# Ducted vs. Recirculating Range Hood for a New-Home Rough-In

Source: https://brictale.com/build/materials/compare-ducted-vs-recirculating-range-hood-new-home-rough-in
Published: 2026-09-14
Audience: Homeowner
Published by Brictale, a consumer home-intelligence publication. https://brictale.com

## Short answer

Choose a ducted hood when your cooking, fuel, indoor-air, and project constraints justify exhausting captured pollutants outdoors and the team can reserve a compliant duct route. Choose recirculation only when the exact appliance manual and AHJ allow it, you accept filter-limited capture and no outdoor moisture removal, and you can maintain the filters. Release neither option until the hood, duct, power, makeup-air branch, access, and verification owner are recorded.

---

# Ducted vs. Recirculating Range Hood for a New-Home Rough-In

For a new U.S. home, choose a ducted hood when the cooking pattern, fuel, indoor-air goals, and building plan justify sending captured pollutants and moisture outdoors and the team can reserve a compliant route. Choose recirculation only when the exact hood manual and the actual AHJ allow it, you accept filter-limited capture and no outdoor moisture removal, and you can maintain the filters. Release neither option until the hood, duct, power, makeup-air, access, and verification owners are documented.

This guide covers a homeowner coordinating a designer, builder, HVAC or ventilation installer, electrician, and local authority having jurisdiction (AHJ) from design through rough-in. The default market is the United States. “Code” below never means a nationwide rule: the Virginia provisions are a named adopted-jurisdiction example, while the state, county, city, township, or other authority that adopted the rule for the project controls. Commercial kitchens, unsafe combustion testing, and nationwide code conclusions are outside scope.

![Split technical view of outdoor ducted exhaust and filtered recirculating range-hood paths](https://brictale.com/images/home/build/materials/compare-ducted-vs-recirculating-range-hood-new-home-rough-in/ducted-recirculating-architecture.webp)

## 1. Make the architecture decision before the rough-in release

A ducted or recirculating hood is ready for rough-in only when the homeowner can explain what the system must remove, where the removed air goes, which constraints govern the choice, and who will verify each item before the wall or ceiling closes. If any of those answers is missing, the correct status is **revise** or **defer**, not a guessed hood opening.

### The decision in one sentence

Use a ducted hood if outdoor exhaust is feasible and valuable enough to justify the duct, termination, pressure, noise, makeup-air, framing, electrical, envelope, and maintenance coordination. Use a recirculating hood if a duct cannot be responsibly routed or the project has deliberately accepted its limits, after the exact product instructions and local authority have approved that path.

The distinction is functional, not merely cosmetic. A ducted hood captures air above the cooking surface and sends it through a duct and exterior termination. A recirculating hood moves air through grease and other filters, then returns the treated air to the kitchen. The second arrangement can reduce some airborne grease and odor under the exact conditions for which its filters were designed, but it does not create an outdoor exhaust path. It therefore cannot remove indoor moisture, heat, or combustion products to the exterior in the way a properly installed ducted system can.

EPA identifies cooking as a source of excess indoor moisture and says kitchen exhaust should be vented directly outside; it also explains that local kitchen fans remove contaminants and moisture at their source and increase outdoor-air ventilation. That is why a recirculating option should be treated as a constrained alternative, not as an equivalent indoor-air result. See the [EPA remodeling and indoor-environment guidance](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling) for the scope of that advice.

### A three-state release gate

Record one of these states in the design decision log:

| Status | Meaning | Required next action |
| --- | --- | --- |
| **Go** | A named hood and appliance are selected; the route, performance basis, electrical point, makeup-air branch, termination, access, and verification owners agree. | Builder may release the coordinated rough-in drawing and procure only the approved configuration. |
| **Revise** | The architecture is plausible, but an input, manual, route, code interpretation, or trade scope conflicts. | Return the open item to the responsible designer, HVAC installer, electrician, builder, or AHJ; do not close the assembly. |
| **Defer** | The appliance, hood, jurisdiction, or room layout is not sufficiently known to make a safe comparison. | Preserve a larger chase or flexible service zone where practical, then set a decision deadline before insulation, drywall, or cabinet fabrication. |

The word “approved” has a narrow meaning in this worksheet. It means the person with authority for that part has recorded a decision. A homeowner can approve the cooking pattern and maintenance commitment. A designer can coordinate cabinet, ceiling, and exterior appearance. The HVAC or ventilation professional must resolve duct and airflow design. The electrician must resolve the circuit and controls. The builder must coordinate the physical sequence. The AHJ decides what the adopted local rule and permit review require. Do not make one person silently carry all five responsibilities.

### What changes the decision most

The highest-leverage inputs are not the retail price or the hood’s free-air CFM. They are:

1. **Appliance and fuel:** induction, conventional electric, natural gas, propane, or another fuel; nominal burner or element layout; and the appliance’s own installation instructions.
2. **Cooking pattern:** occasional boiling, frequent frying, high-heat searing, wok use, open-top broiling, canning, or long simmering; back-burner versus front-burner use; and whether the homeowner will actually run the hood.
3. **Hood geometry:** wall or island location, hood width, capture area, mounting height, canopy depth, and whether the appliance manual imposes a different clearance or airflow requirement.
4. **Rated performance:** airflow in CFM at stated static pressure, speed settings, sones at a stated condition, power draw, certification, and whether the rating applies to ducted or recirculating configuration.
5. **Route:** duct diameter and material, smooth versus flex construction, equivalent length, bends, transitions, termination, fire and weather details, framing, insulation, and access.
6. **House pressure and combustion:** other exhausts operating at the same time, air-sealing level, natural-draft or other non-sealed combustion appliances, and the local makeup-air trigger or design requirement.
7. **Handoff and proof:** who supplies the manual, who draws the route, who installs it, who seals and photographs it, who measures airflow if required, and who records the final model and settings.

If the team cannot fill those fields, the project has not compared two architectures yet. It has compared two product descriptions.

## 2. Establish the inputs, prerequisites, and jurisdiction before comparing products

The first design action is to create a one-page input record and have the designer or builder identify the actual AHJ and adopted rules; only then should the team compare hood models. A model code, product listing, or retailer chart cannot substitute for the project’s address-specific permit path, adopted edition, amendments, and manufacturer instructions.

### Identify the authority having jurisdiction

Write the jurisdiction as a place, not as “U.S. code.” Examples of a useful record are “City of ___ Building Department, ___ County, ___ State,” “___ County mechanical inspection office,” or a state agency when that agency has authority for this project. Ask that office or the permit professional to confirm:

- the adopted residential or mechanical code edition;
- local amendments, energy-code provisions, and permit notes affecting kitchen exhaust;
- whether the project is reviewed under the IRC, the International Mechanical Code (IMC), a state-specific code, or a local code;
- whether the hood must be listed or labeled in a particular way;
- the local interpretation of ductless or recirculating hoods;
- the local threshold or design method for makeup air;
- termination location, clearances, dampers, duct material, and access requirements; and
- what inspection or test record is required before close-in or final approval.

ICC explains that model-code language becomes law only after adoption by the appropriate state or local authority, and that the adopting law can include amendments or changes. The [ICC code-adoption guidance](https://www.iccsafe.org/advocacy/code-adoption-resources/) supports the practical rule: name the actual jurisdiction and attach its answer to the project record. Virginia illustrates why this matters: the [Virginia Department of Housing and Community Development](https://www.dhcd.virginia.gov/codes) says its 2021 codes became effective January 18, 2024, while the [Virginia Uniform Statewide Building Code page](https://www.dhcd.virginia.gov/virginia-uniform-statewide-building-code-usbc) says enforcement is handled by the local government's building inspections department. If the AHJ has not answered, set the status to **defer**. Do not quote a model or state code as if it automatically governs a house in every state, county, or city.

### Use an accessible adopted-jurisdiction example, not a national conclusion

Use Virginia only as a named, accessible example of how an adopted rule changes the decision. The [Virginia incorporated-code regulation](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/) changes IMC Section 505.3 so that, in Group R buildings, a listed and labeled ductless range hood need not discharge outdoors when it follows the manufacturer's instructions and mechanical or natural ventilation is otherwise provided. The same official regulation changes VRC Section M1503.6 to require makeup air for an exhaust hood system capable of exhausting more than 400 CFM, with Virginia-specific exceptions and automatic simultaneous operation requirements. Those are Virginia provisions, not a nationwide threshold or permission slip. For any other project, identify the actual state, county, city, township, or other enforcing authority and read its adopted text alongside the hood manual.

This distinction matters in both directions. A local rule may be more restrictive, may use a different edition, or may incorporate a different mechanical code. A local reviewer may also ask for a listed product, a duct detail, a calculation, or a test even when a homeowner has found a general online statement that sounds permissive. Conversely, an adopted-code exception does not mean every product may be installed ductless: the exception still depends on listing, instructions, and the other conditions in the adopted rule.

### Complete the homeowner input record

Use one line per input, with a source or responsible person. Blank is a useful result; it exposes an unresolved decision.

| Input | Record this precisely | Owner or source |
| --- | --- | --- |
| Address and AHJ | Project address, reviewing authority, phone or permit portal, adopted code edition, amendments, permit number when known | Homeowner plus builder or permit professional |
| Appliance | Manufacturer, model, fuel, width, cooking surface dimensions, installation manual URL or file, open-top broiler or specialty modes | Homeowner and appliance supplier |
| Cooking pattern | Typical and peak method, duration, burner location, frying or searing frequency, whether the hood will run during and after cooking | Homeowner |
| Hood | Manufacturer, model, wall/island, width, depth, mounting height, ducted and recirculating configurations, filter type, certified ratings | Designer and homeowner |
| Airflow | CFM at each relevant speed and the stated static-pressure condition; identify free-air, rated, or installed value | Hood manual, HVI or certification record, HVAC professional |
| Sound | Sones and test condition at the selected speed and configuration | Hood manual or certification record |
| Duct | Inside diameter, material, smooth or flex, straight length, elbows, transitions, termination, damper, access, insulation and firestopping | HVAC professional and builder |
| Other exhaust | Bath fans, whole-house exhaust, dryers, central vacuum exhaust, fireplace or other exhaust that may run concurrently | HVAC professional and homeowner |
| Combustion | Fuel-burning appliances, direct-vent or sealed status, natural-draft or mechanical-draft details, location relative to air barrier | HVAC professional and qualified combustion professional |
| Makeup air | Local trigger, calculated or selected supply rate, duct/damper location, tempering or conditioning, control interlock, service access | HVAC professional and AHJ |
| Electrical | Voltage, amperage, circuit, disconnect or service access, outlet or hardwire location, controls and lighting load | Electrician and hood manual |
| Framing and finish | Joist/stud conflicts, chase, cabinet opening, exterior termination location, siding/roof detail, acoustic isolation, fireblocking | Designer and builder |
| Verification | Airflow method, pressure or combustion test where applicable, visual checks, photos, documents, and responsible witness | Builder, HVAC professional, electrician, AHJ |

### Separate prerequisites from preferences

Prerequisites are conditions that can disqualify a path: an AHJ prohibition, a hood that cannot be installed in the planned configuration, no compliant exterior route, a combustion risk that has no resolved makeup-air or sealed-combustion strategy, or no way to service a filter or damper. Preferences are tradeoffs: quiet operation, minimal ceiling bulkhead, lower heat loss, fewer exterior penetrations, high capture performance, or a particular cabinet appearance.

List prerequisites first. A quiet hood that cannot exhaust through the available route is not a quiet solution; it is an uninstalled product. A ductless unit that fits the cabinet but cannot be maintained is not a low-coordination solution; it has deferred maintenance risk. A large hood that wins a CFM comparison but trips a combustion-safety branch is not a stronger design.

### The first handoff

The homeowner hands the completed input record and the appliance manual to the designer or builder. That person returns a coordinated plan showing the candidate hood envelope, cabinet and ceiling geometry, and a preliminary route. The HVAC professional then marks the route and pressure basis. The electrician confirms power after the actual hood is selected. The team does not release the framing opening until those inputs are tied to one model and one configuration.

![Homeowner range-hood rough-in inputs flowing through coordinated trade handoffs](https://brictale.com/images/home/build/materials/compare-ducted-vs-recirculating-range-hood-new-home-rough-in/rough-in-decision-handoff-map.webp)

## 3. Compare what each architecture can remove—and what it cannot

A ducted hood is the stronger choice for removing captured moisture, heat, odors, grease-laden air, and fuel-combustion products from the home; a recirculating hood is a filter-based compromise whose result depends on capture, filter condition, cooking pattern, and user operation. Induction reduces combustion pollutants at the appliance, but it does not make grease, particles, odors, or cooking moisture disappear.

### Capture is upstream of either destination

The hood must first capture the rising and moving plume above the cooking surface. Only the air that enters the hood can be exhausted or filtered. Capture depends on canopy geometry, width and depth, mounting height, cross-drafts, burner or element location, pan shape, cooking intensity, and fan speed. A high airflow number cannot compensate indefinitely for a hood mounted too high, too narrow, or too far behind a front burner.

HVI describes a range hood as an enclosure and fan intended to capture heat, odors, gases, grease, steam, and smoke above the cooking surface, and says performance must match the cooking type and frequency. It also notes that hood width should match the range and that the manufacturer’s recommended height matters. Use the [HVI range hood performance brochure](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf) as a comparison prompt, not as a substitute for the selected hood’s manual.

Capture questions for the homeowner are concrete:

- Is the hood at least as wide as the cooking surface, or does the exact manual require an overhang?
- Will frequent cooking occur on the front burners or elements, where a shallow canopy may capture less effectively?
- Is the cooking surface on an island, where cross-drafts and the absence of a wall can change capture?
- Will the hood be mounted at the manual’s maximum height, and if so, does the selected airflow still make sense?
- Does the plan include an open-top broiler, griddle, wok, or high-heat mode that changes the appliance or hood requirement?
- Can the homeowner commit to starting the hood before the plume grows and leaving it on after cooking?

### What ducted exhaust adds

When capture is successful, a ducted system can carry away the captured air. The practical benefits are:

- **Moisture removal:** water vapor from boiling and simmering has an outdoor path rather than being returned to the room.
- **Heat removal:** some sensible heat leaves with the exhaust air, which can be a comfort benefit in a tight home even though it creates an energy and makeup-air tradeoff.
- **Odor and particle removal:** captured cooking emissions are sent toward the exterior termination rather than recirculated through a filter and returned.
- **Gas-appliance branch:** combustion products from gas cooking have a direct outdoor-exhaust path when the hood is correctly sized, installed, and operated.
- **Maintenance visibility:** grease filters still need cleaning, but the system does not depend on a saturated odor filter to provide the only treatment.

These are capabilities, not guarantees. A poorly routed duct, stuck damper, blocked termination, or hood that never runs can make a theoretically superior architecture ineffective. EPA’s cooking guidance says to turn on an outdoor-vented hood whenever cooking, run it for 10–20 minutes afterward, use back burners when possible, and clean the grease filter routinely. Keep those instructions in the homeowner handoff. See the [EPA cooking infographic page](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking-infographic).

### What recirculation can and cannot do

Recirculation may be reasonable when the exterior route is impossible, the local rule and manual allow the configuration, the cooking pattern is modest, and the homeowner accepts frequent inspection and replacement of filters. It can preserve conditioned air, avoid a roof or wall penetration, reduce framing and duct coordination, and sometimes simplify a late layout change.

Its limits must be written into the decision, not hidden in the product name:

- the air returns to the kitchen rather than being discharged outdoors;
- moisture from cooking remains an indoor load unless another exhaust strategy removes it;
- heat remains primarily indoors;
- gas combustion products are not sent through an outdoor hood duct;
- filter performance depends on the exact filter media, its condition, airflow, loading, and replacement schedule; do not assume removal of a pollutant unless the exact manual or tested product documentation says so;
- some odors may remain or return when capture is incomplete or a filter is loaded; this is a bounded inference from manufacturer guidance, not a universal removal percentage;
- a recirculating hood does not automatically satisfy a local requirement for mechanical outdoor exhaust or whole-home ventilation; and
- an indoor air cleaner elsewhere in the house is not proof that the hood captures the cooking plume at its source.

If the homeowner chooses recirculation, specify the exact replacement filter part number, access path, cleaning interval, saturation indicator if provided, and the separate plan for moisture and general kitchen ventilation. EPA recommends outdoor air and supplemental filtration strategies when an outdoor-vented hood is absent, but its guidance also tells the reader to consult a professional when unsure. Read the [EPA cooking strategies](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking) as supplemental indoor-air guidance, not as evidence that recirculation equals outdoor exhaust.

Broan-NuTone provides a useful manufacturer-specific boundary for this comparison: its official [range-hood FAQ](https://broan-nutone.com/en-us/home/customer-service/range-hood-faqs) says non-ducted filters trap some grease and odors from normal cooking, while humidity, smoke, and heat are recirculated. It also says replacement normally depends on the frequency and type of cooking, commonly every three to six months, and warns that neglected filters lose their grease- and odor-catching effect. Treat that as a conditional product-family example, not as the rating or replacement interval for an unselected hood; the exact manual and filter instructions control.

### Fuel changes the risk branch

DOE explains that induction creates heat in compatible cookware and avoids the indoor combustion pollutants associated with burning gas, including nitrogen oxides, carbon monoxide, and formaldehyde. That difference is relevant to the range-hood decision, but it is not an argument to omit capture. Frying, searing, boiling, smoke, grease, odors, and moisture still occur with induction and electric cooking. See [DOE’s induction cooking explanation](https://www.energy.gov/articles/making-switch-induction-stoves-or-cooktops).

For natural gas or propane, add the combustion branch to the release gate. EPA states that a properly sized hood directly vented outdoors should be used with a gas range, and warns that larger fans can depressurize a home enough to cause backdrafting or other problems. EPA also recommends that combustion equipment be tested after installation with a worst-case depressurization procedure by the installer or another qualified professional. Those statements are in the [EPA combustion-appliance guidance](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling).

The homeowner may record fuel type, appliance model, locations, and simultaneous exhausts. The homeowner should not deliberately depressurize the house, disable safety controls, manipulate gas components, or perform an improvised combustion-spillage test. Ask the qualified professional what test is appropriate and have the report attached to the final record.

### The second handoff

The designer hands the capture and fuel requirements to the HVAC professional. The HVAC professional returns a ducted and/or recirculating performance basis: the candidate configuration, rated airflow condition, route, makeup-air branch, and verification method. If the ducted path fails, the homeowner must decide whether to redesign the route, reduce the selected operating point within the manual and code, change the hood or appliance, or accept a documented recirculating path with supplemental ventilation. That is the next decision—not “buy the strongest fan.”

## 4. Compare airflow, sound, duct pressure, and energy using matching units

Compare a hood only at the same configuration and stated pressure condition; a free-air CFM and a ducted CFM at static pressure are not interchangeable. The working comparison should show certified or manufacturer data, sones, power, duct diameter, smoothness, length, bends, and termination—not one headline airflow number.

### Use the hood’s performance table correctly

Request the exact manual or technical sheet for the hood and record:

- CFM at each speed;
- the pressure condition for each CFM value, such as 0.10 or 0.25 inches water gauge (in. w.g.), or the manufacturer’s stated condition;
- whether the value is free-air, rated, or installed;
- whether it applies to ducted, recirculating, wall, island, internal-blower, or remote-blower configuration;
- the sones at the same relevant speed and condition;
- voltage, amperage, wattage, and control requirements;
- minimum and maximum duct size;
- maximum equivalent length or approved fittings;
- backdraft damper, transition, termination, and clearance requirements; and
- filter type and replacement parts for recirculating operation.

ENERGY STAR’s ventilation-fan criteria use static-pressure reference measurements, require a range hood to meet the specification in each possible configuration, and distinguish airflow and sound test conditions. The [ENERGY STAR ventilation-fan criteria](https://www.energystar.gov/products/ventilation_fans/key_product_criteria) are a useful reminder to keep the pressure basis beside the CFM. HVI similarly says range-hood performance includes airflow, sound, power, and ducting, and that actual performance varies by model and manufacturer. The [HVI certified-performance explanation](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf) is useful when a salesperson presents an unexplained “maximum CFM.”

Do not write “this hood is 600 CFM” without an attached condition. Write “600 CFM at ___ in. w.g., speed ___, configuration ___, source ___.” If no pressure condition is available, mark the value as unconditioned and ask the HVAC professional how it can be compared. Absence of a rating is not permission to assume performance.

### Think in pressure losses, not only nominal duct size

The fan must overcome resistance from the hood inlet, filters, transitions, duct friction, elbows, termination, damper, and any special fitting. A long, small, rough, flex, or sharply bent route can reduce delivered airflow and increase sound. The exact pressure calculation belongs to the HVAC or ventilation professional, but the homeowner can make the inputs visible and catch an incomplete quote.

Use this worksheet notation:

```text
L_eq = L_straight + Σ L_elbow + Σ L_transition + L_termination
P_total = P_hood/filter + P_duct(L_eq, diameter, material, airflow) + P_damper/termination
Q_installed = fan-curve airflow at P_total
```

Here, `L_eq` is equivalent duct length in feet, `P_total` is total pressure loss in in. w.g., and `Q_installed` is the delivered airflow in CFM at that pressure. The formula is a planning structure, not a substitute for a fan curve or duct friction method. Ask the HVAC professional to replace each generalized term with the hood manual’s data and the selected duct calculation.

ENERGY STAR’s kitchen-exhaust reference gives a concrete program example of why route details matter. Its table changes allowable length with fan rating, duct diameter, and flex versus smooth duct; it assumes no elbows, then instructs the user to subtract 15 feet of allowable length per elbow and use the smallest diameter when diameters vary. Read the [ENERGY STAR kitchen exhaust reference guide](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf), but do not treat its table as the project’s local code or the hood manual.

The guide’s illustrative example starts with a 62 CFM fan rating, uses the next larger 80 CFM column, and shows that 5-inch flex has an 81-foot maximum before elbow deductions. Two elbows remove 30 feet, leaving 51 feet; 44 feet of straight duct then fits that example. This is a compliance illustration for the ENERGY STAR program, not a universal allowance for a different hood. It is valuable because it shows the direction of sensitivity: adding fittings can erase the apparent margin quickly.

### A source-derived illustrative pressure comparison

The following is a modeled example, clearly labeled illustrative. It is not a field measurement and does not represent a particular manufacturer’s fan curve.

**Inputs**

- Candidate hood: 36-inch wall hood, ducted configuration.
- Selected operating point for comparison: 300 CFM.
- Hood and filter allowance: 0.10 in. w.g. at 300 CFM, assumed only for the model.
- Smooth round duct route A: 8-inch diameter, 18 feet straight, two 90-degree elbows, one termination; modeled equivalent-length additions are 15 feet per elbow and 10 feet for the termination.
- Smooth round duct route B: 6-inch diameter, 18 feet straight, two 90-degree elbows, one termination; the same modeled fitting additions.
- Illustrative friction allowances: 0.015 in. w.g. per 100 equivalent feet for 8-inch duct at this operating point and 0.055 in. w.g. per 100 equivalent feet for 6-inch duct at this operating point.

**Formula**

```text
L_eq = straight length + (2 × elbow allowance) + termination allowance
P_duct = friction allowance × L_eq ÷ 100
P_total = hood/filter allowance + P_duct
```

**Calculation**

Route A: `L_eq = 18 + (2 × 15) + 10 = 58 ft`.

Route A: `P_duct = 0.015 × 58 ÷ 100 = 0.0087 in. w.g.`.

Route A: `P_total = 0.10 + 0.0087 = 0.1087 in. w.g.`.

Route B: `L_eq = 58 ft` as well.

Route B: `P_duct = 0.055 × 58 ÷ 100 = 0.0319 in. w.g.`.

Route B: `P_total = 0.10 + 0.0319 = 0.1319 in. w.g.`.

The modeled 6-inch route therefore has about 0.0232 in. w.g. more pressure loss before the actual transition, damper, hood inlet, and termination data are known. That number is not large enough to predict a particular delivered CFM without the actual fan curve. Its purpose is to expose why “both routes are 18 feet” is not a complete comparison.

**Sensitivity**

| Change to the illustrative model | 8-inch route pressure | 6-inch route pressure | What it tells the homeowner |
| --- | ---: | ---: | --- |
| Base: 18 ft, two elbows, one termination | 0.1087 in. w.g. | 0.1319 in. w.g. | Diameter changes the pressure even when length is equal. |
| Add 20 ft straight duct | 0.1117 in. w.g. | 0.1429 in. w.g. | A longer small route loses margin faster under the assumed allowances. |
| Add one more elbow | 0.1110 in. w.g. | 0.1402 in. w.g. | Fittings matter; count them before framing. |
| Replace smooth with a higher-resistance flex path, new allowance required | Not calculated | Not calculated | Do not reuse smooth-duct numbers for flex; obtain the correct table or calculation. |

The limitations are deliberate. The illustrative friction allowances are assumptions, not sourced measured values; a real pressure calculation depends on airflow, duct dimensions, fitting geometry, roughness, transition shape, damper, termination, and the hood’s own curve. The homeowner should show the arithmetic to the HVAC professional and ask for a project-specific replacement. The useful output is a missing-input list and a comparable handoff, not a claim that Route A will deliver exactly 300 CFM.

![Technical cutaway comparing wide and narrow hood ducts across bends and an exterior termination](https://brictale.com/images/home/build/materials/compare-ducted-vs-recirculating-range-hood-new-home-rough-in/duct-pressure-sensitivity-cutaway.webp)

### Compare sound as a system result

Sones belong beside airflow and pressure, not in a separate shopping column. HVI explains that sound comes from airflow into the hood, the fan, and the ducting; it recommends a low sone rating and properly sized and installed ductwork when minimizing sound. A larger fan operated against an undersized route can be louder and deliver less than expected. Conversely, a remote blower can move some fan noise away from the kitchen while adding route, access, wiring, and service coordination.

Ask the team to state the desired operating speed for everyday simmering and the peak speed for frying or searing. Compare the sone value at those speeds and conditions. Do not compare “quiet at low” on one product with “maximum CFM at high” on another. Write down whether the homeowner would tolerate the everyday setting; a control that is technically available but never used is not a reliable design.

### Compare energy and pressure honestly

The ducted choice removes some conditioned air and may require makeup air or additional heating and cooling. That is a real operating tradeoff. The recirculating choice avoids intentional exhaust loss but retains indoor moisture and heat and shifts more responsibility to filters and other ventilation. The right comparison asks which load the project is willing and able to manage.

Do not claim an annual energy cost without local climate, operating hours, airflow, temperature, heating fuel, cooling system, makeup-air strategy, and utility rates. If energy is material to the decision, ask the HVAC professional for a scenario comparison using those inputs. A homeowner can record the scenarios; a homeowner should not turn a generic CFM number into a false annual savings figure.

### The third handoff

The HVAC professional returns a route schedule and pressure basis with the exact hood configuration. The homeowner compares that record with the hood manual and cooking pattern. The designer checks whether the route still fits the room and exterior design. If the pressure basis is missing, the decision remains **revise**. If the selected hood’s ratings are not configuration-specific, the team must get better product documentation or select another product before rough-in.

## 5. Resolve makeup air, combustion, electrical, framing, and exterior coordination

The ducted option is not released until the team has resolved the actual jurisdiction’s makeup-air and combustion requirements, the hood’s electrical load, the duct and termination path, and the access and framing consequences; recirculation still requires power, filter access, and a separate plan for moisture and kitchen ventilation. These are coordinated building decisions, not cabinet-afterthoughts.

### Makeup air is a branch, not a universal number

When air leaves a tight home, replacement air must come from somewhere. Uncontrolled replacement can arrive through cracks, attached garages, chimneys, combustion vents, or other undesirable paths. A designed makeup-air system may add a dedicated outdoor intake, damper, control interlock, tempering, filtration, and service access. The exact trigger, rate, temperature treatment, and approval path are jurisdiction- and system-specific.

Virginia’s adopted rule gives one concrete example: its official regulation states that an exhaust hood system capable of exhausting more than 400 CFM must receive makeup air at approximately the exhaust rate above 400 CFM, with a means of closure and automatic simultaneous operation, subject to Virginia’s listed exceptions. The [Virginia regulation](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/) is not a national threshold. Ask the actual AHJ and HVAC professional what governs this house, and record whether the project is in Virginia or under another jurisdiction’s adopted rule.

Use this branch record:

| Question | If yes | If no or unknown |
| --- | --- | --- |
| Is there a fuel-burning appliance inside the dwelling air barrier? | Identify whether it is direct-vent, sealed-combustion, induced-draft, power-vented, or natural-draft; hand the information to the qualified HVAC/combustion professional. | Record the confirmation; do not assume an induction cooktop removes risk from a furnace, fireplace, water heater, or other appliance. |
| Can the hood exceed the local or adopted-code trigger? | Resolve makeup-air rate, control, damper, discharge location, tempering, and access before rough-in. | Get the jurisdiction’s written or permit-based answer; do not use a retailer threshold. |
| Can other exhaust operate at the same time? | Include bath fans, dryer, whole-house exhaust, and other exhaust in the pressure and combustion review. | Record the assumed operating schedule and verify it with the HVAC professional. |
| Can the makeup-air path be serviced? | Show access to filters, damper, control, and any heater or tempering device. | Revise the route; a hidden inaccessible component is not a complete design. |

A dedicated makeup-air duct that discharges into the wrong room, creates drafts at the cooktop, freezes a pipe, or cannot be serviced can damage the intended result. Ask where supply air will enter relative to the hood, occupants, smoke alarms, combustion appliances, and return-air pathways. The professional must resolve the design; the homeowner’s job is to ensure the question appears in the scope.

### Combustion safety must be independently owned

EPA says natural-draft combustion can be overcome by depressurization, causing spillage or backdrafting, and it recommends professional inspection and a worst-case depressurization test after combustion and ventilation equipment are installed. The [EPA remodeling guidance](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling) also distinguishes sealed combustion, which draws combustion air directly from outside, from appliances that use air from the home.

The hood installer may not be the person who can sign off the furnace, fireplace, water heater, or fuel-gas installation. Assign the combustion review to a qualified HVAC or combustion professional and state what equipment is included. The homeowner should receive the test method, conditions, instruments or professional report as appropriate, result, exceptions, and corrective action. A carbon-monoxide alarm is a backup, not a replacement for proper installation, operation, maintenance, and testing.

Stop the process and call the responsible professional if occupants smell combustion products, a CO alarm activates, a flame behaves unexpectedly, or an appliance spills during an authorized professional test. Do not repeat a risky test to make a worksheet turn green.

### Electrical coordination

Obtain the hood manual before the electrician roughs in the box. Record voltage, circuit rating, amperage, lighting load, control wiring, remote-blower wiring, disconnect or service location, and any manufacturer requirement for a dedicated circuit. The exact circuit requirement is a product instruction and local electrical-code question, not something a generic comparison can safely invent.

For a ducted hood, the electrician may coordinate with the makeup-air control so the exhaust and damper operate as intended. For a remote blower, the electrician may have more than one connection and a control interlock. For recirculation, the electrical work is simpler only if the selected hood is simple; lighting, controls, sensors, and a filter indicator still need access and a final test.

The handoff is complete when the electrician marks the outlet or junction-box location on the coordinated plan, the builder confirms it will remain accessible as required, and the hood supplier confirms the connection method. Photograph the rough-in before insulation or drywall, but do not treat a photograph as proof that the circuit is energized correctly.

### Framing and the building envelope

The duct route can collide with joists, trusses, studs, cabinets, plumbing, electrical runs, fireblocking, insulation, and air-sealing details. The builder should not notch or drill structural members from a hood sketch without the responsible designer or engineer’s direction. A chase that looks available on a plan may be needed for another system or may require a framed opening and protection detail.

For an exterior wall termination, coordinate the cap, backdraft damper, weather-resistive barrier, flashing, siding, soffit, roof, and clearance from windows, doors, air intakes, property lines, and neighboring openings according to the adopted rules and product instructions. The termination should be visible for inspection and accessible for cleaning or replacement where required. Avoid a discharge location that sends greasy air onto a walkway, patio, window, or fresh-air intake.

The duct must be sealed with a suitable method compatible with the material and local requirements. EPA warns that ducts should be tightly sealed and that standard cloth duct tape is not a suitable duct sealant; its [remodeling guidance](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling) is a useful source for the air-leakage and pressure rationale. The exact sealant and firestopping detail still belong to the installer and AHJ.

### The fourth handoff

The designer and builder issue one coordinated rough-in drawing. It should show the hood centerline and opening, appliance relationship, duct centerline and size, each bend and transition, termination, damper and access, makeup-air intake and discharge, electrical connection, framing notes, and any required fire, air, or weather sealing. The HVAC professional signs the pressure and makeup-air portion; the electrician signs the power portion; the builder owns the physical coordination; the AHJ’s permit or inspection requirements remain controlling.

![House pressure diagram linking hood exhaust, makeup-air intake, and combustion review](https://brictale.com/images/home/build/materials/compare-ducted-vs-recirculating-range-hood-new-home-rough-in/makeup-air-combustion-coordination.webp)

## 6. Use the source-derived worksheet and decision matrix

The decision matrix should score the two architectures against the project’s stated priorities and disqualify a path when a prerequisite fails; it should not pretend that one universal point total can determine every home. The worksheet below is the original contribution for this guide: it is reproducible from the named sources, the selected hood manual, the actual route, and the homeowner’s recorded assumptions.

### Source-derived range hood rough-in worksheet and decision matrix

**Summary.** This worksheet converts appliance fuel, cooking pattern, certified hood performance, duct route, makeup-air branch, electrical point, access, maintenance, and verification responsibility into a documented **go**, **revise**, or **defer** decision. It compares architectures, not brands.

**Method.** Extract decision inputs from EPA, DOE, ENERGY STAR, HVI, Broan-NuTone manufacturer guidance, and accessible Virginia adopted-code text; compare ducted and recirculating paths by pollutant destination, pressure, sound, coordination, maintenance, and verification; then run an illustrative airflow-and-pressure sensitivity using explicit units, assumptions, and formulas. The cited sources establish the questions and selected technical claims; the matrix is Brictale’s synthesis, not measured research. Source links: [EPA cooking guidance](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking), [DOE induction context](https://www.energy.gov/articles/making-switch-induction-stoves-or-cooktops), [ENERGY STAR home ventilation context](https://www.energystar.gov/newhomes/features-benefits/indoor-air-quality-features), [ENERGY STAR fan criteria](https://www.energystar.gov/products/ventilation_fans/key_product_criteria), [ENERGY STAR duct reference](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf), [HVI performance guidance](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf), [Broan-NuTone range hood FAQ](https://broan-nutone.com/en-us/home/customer-service/range-hood-faqs), [Virginia kitchen-exhaust provisions](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/), [Virginia code effective date](https://www.dhcd.virginia.gov/codes), and [Virginia local enforcement](https://www.dhcd.virginia.gov/virginia-uniform-statewide-building-code-usbc).

**Limitations.** This is a source-derived planning aid, not an engineering design, code determination, manufacturer installation instruction, combustion-safety test, airflow measurement, or field test. The actual AHJ, designer, HVAC professional, electrician, and hood manual control the project-specific release. It does not certify that a selected system captures a particular percentage of pollutants, meets a local code, or delivers its nameplate CFM after installation.

### Fill the comparison columns

| Decision field | Ducted entry | Recirculating entry | Release question |
| --- | --- | --- | --- |
| Pollutant destination | Captured air goes through an exterior duct and termination | Captured air passes through specified filters and returns indoors | Is the difference acceptable for the actual cooking pattern? |
| Moisture and heat | Outdoor path, with exhaust and makeup-air energy tradeoff | Remains primarily an indoor load; separate ventilation needed | Who controls kitchen humidity and heat? |
| Fuel branch | Required combustion and depressurization review for gas or other fuel-burning context | Cannot use recirculation as a claim that combustion products are exhausted outdoors | Has a qualified professional resolved all fuel-burning appliances? |
| Hood and appliance | Exact ducted model configuration, width, height, and manual | Exact ductless configuration, filter parts, and manual | Are both entries based on the same appliance and geometry? |
| Airflow | CFM at stated static pressure and selected speed; installed verification method | CFM or circulation rating in exact filter configuration, without calling it outdoor exhaust | Are the ratings configuration-specific? |
| Sound | Sones at the same pressure and speed basis, plus duct noise | Sones in recirculating configuration, plus filter loading noise | Will the homeowner use the everyday setting? |
| Duct and termination | Diameter, material, length, bends, transitions, damper, cap, access, sealing | No hood exhaust duct; still record any separate kitchen or whole-house exhaust | Does the ducted route fit without unsafe structural changes? |
| Makeup air | AHJ and HVAC design, rate, damper, supply, tempering, control, access | Usually no hood exhaust makeup-air branch, but other exhaust may still need review | Is the no-duct assumption explicit and approved? |
| Electrical | Voltage, amperage, circuit, controls, remote blower, interlock | Voltage, amperage, controls, lighting, filter indicator | Has the actual manual reached the electrician? |
| Maintenance | Grease filter, hood interior, damper, termination, duct as specified | Grease filter plus manufacturer-specified odor or other recirculation filter with replacement cost and access | Can the homeowner clean and replace everything on schedule? |
| Verification | Visual route check, airflow test or prescriptive check if required, controls, damper, combustion test where applicable | Filter installation, controls, capture operation, separate ventilation, AHJ conditions | Who records proof before close-in and at final? |

### Apply hard stops before any points

Mark **fail** and stop the path if:

- the AHJ has not confirmed whether the ductless configuration is permitted;
- the hood is not listed, labeled, or installed in the configuration required by the adopted rule and manual;
- the selected duct route cannot meet the hood manual, adopted rule, or verified design;
- the duct would terminate in an attic, crawl space, soffit, or other prohibited location;
- a makeup-air or combustion branch is triggered but has no design and responsible professional;
- a required electrical connection is unknown or inaccessible;
- a recirculating filter cannot be removed, cleaned, or replaced without damaging finished work; or
- the homeowner’s intended cooking pattern exceeds the selected system’s documented basis.

Do not let a high score on price, appearance, or energy loss override a hard stop. A fail is a design signal, not a reason to hide the input.

### Use a transparent weighted comparison only after prerequisites pass

If both paths pass the hard stops, use a 0–3 rating for each project criterion:

- 0 = does not meet the stated need;
- 1 = meets it with a significant unresolved tradeoff;
- 2 = meets it with a manageable tradeoff;
- 3 = strongly meets it with documented margin.

Choose weights with the homeowner before scoring. For a homeowner who fries several times per week, pollutant and moisture removal might receive weight 5, capture geometry weight 5, and maintenance weight 3. For a small, lightly used kitchen where an exterior route would require a major redesign, route feasibility might receive weight 5, energy loss weight 4, and pollutant removal weight 4. There is no honest universal weighting.

```text
weighted score = Σ (criterion weight × architecture rating)
```

Example, labeled illustrative: assume both paths have passed hard stops. The homeowner sets weights of capture 5, moisture/heat control 4, route feasibility 5, sound 2, maintenance 3, and verification confidence 4. The ducted path is rated 3, 3, 1, 2, 2, 3. The recirculating path is rated 2, 1, 3, 2, 1, 2.

```text
ducted = (5×3) + (4×3) + (5×1) + (2×2) + (3×2) + (4×3)
       = 15 + 12 + 5 + 4 + 6 + 12 = 54

recirculating = (5×2) + (4×1) + (5×3) + (2×2) + (3×1) + (4×2)
              = 10 + 4 + 15 + 4 + 3 + 8 = 44
```

The 10-point difference is not a market ranking. It shows which assumptions drive the decision. If route feasibility changes from 1 to 3 for ducted after the designer finds a compliant chase, the ducted score rises by `5 × (3 − 1) = 10` to 64. If the homeowner changes from frequent frying to occasional low-heat cooking and reduces the capture weight from 5 to 2, the relative result may change. That is sensitivity analysis: it tells the team what new fact is worth resolving.

### Write the verdict in a handoff-ready format

End the worksheet with:

```text
Selected architecture:
Selected hood and appliance:
Jurisdiction and adopted rule checked:
Primary reason:
Hard stops cleared:
Open assumptions:
HVAC owner and verification method:
Electrician owner and verification method:
Builder close-in hold point:
Homeowner maintenance commitment:
Next decision deadline:
Decision state: GO / REVISE / DEFER
```

The next decision should be specific, such as “HVAC professional returns a fan-curve and duct-pressure calculation by cabinet-release date,” “AHJ confirms ductless exception before permit resubmission,” or “homeowner selects between two named 36-inch hoods after filter-access mock-up.” “Discuss ventilation later” is not a handoff.

## 7. Sequence the design-to-rough-in handoffs

The safe sequence is appliance and cooking brief, jurisdiction check, hood configuration, route and pressure design, makeup-air and combustion review, electrical and framing coordination, procurement, rough-in inspection, and only then close-in; changing the hood after drywall turns a coordinated decision into a change order and may remove the space needed to fix it.

### Stage 1: homeowner brief before cabinet design

The homeowner records the appliance preference and likely model, fuel, cooking pattern, cooking surface width, special modes, desired quietness, maintenance tolerance, and whether outdoor exhaust is a priority. Use verbs and frequencies: “fry twice weekly,” “boil pasta most nights,” “sear steaks monthly,” or “rarely cook.” A vague statement such as “we cook a lot” cannot set a useful airflow or filter requirement.

The homeowner also records constraints: exterior wall or roof route, island or wall location, ceiling height, cabinet style, budget range, energy priorities, and tolerance for a soffit or chase. This is not an engineering calculation; it is the input the professionals need to design one.

**Handoff:** homeowner → designer/builder. **Record:** appliance manual or provisional model, marked-up plan, cooking brief, open questions.

### Stage 2: designer and builder reserve geometry

The designer checks hood width, depth, height, cabinetry, sight lines, structural framing, ceiling finish, and exterior termination appearance. The builder checks whether a route can be physically built without compromising structural members, fireblocking, insulation, air sealing, weather protection, or other systems. If a chase is needed, show it now.

For a recirculating path, reserve the filter access area and confirm that cabinet doors or shelves will not block removal. For a ducted path, reserve the transition, duct, damper, access, and termination, not merely a circular line above the cabinet. An “8-inch route” that narrows to 5 inches inside the cabinet is a 5-inch bottleneck until the professional proves otherwise.

**Handoff:** designer/builder → HVAC professional. **Record:** coordinated plan with candidate route, dimensions, elevation, and constraints.

### Stage 3: HVAC or ventilation professional sets the performance basis

The HVAC professional reviews the selected manual, captures the route, calculates or selects the duct basis, identifies the fan curve or rated airflow condition, and evaluates interactions with other exhaust. Ask for a drawing or schedule that records every bend, transition, diameter change, termination, and damper. Ask how installed airflow will be confirmed.

The professional also identifies the makeup-air and combustion branch. If the home has a gas furnace, fireplace, water heater, or other fuel-burning appliance, the review must identify whether it is sealed/direct-vent, induced-draft, power-vented, or natural-draft and how the exhaust scenario affects it. A new induction range does not remove the need to review other combustion appliances.

**Handoff:** HVAC professional → homeowner, designer, builder, electrician, and AHJ as required. **Record:** pressure basis, makeup-air decision, assumptions, test plan, and unresolved exceptions.

### Stage 4: AHJ and electrician close the rule and power branches

The builder or permit professional sends the relevant plan and product information to the AHJ through the required permit process. The homeowner keeps the jurisdiction name and response with the project records. If the AHJ requests a revision, the design state returns to **revise**, even if a retailer says the hood is common.

The electrician receives the exact hood manual and any remote-blower or makeup-air control diagram. The electrician marks the circuit and connection location. The builder confirms that the connection remains accessible and protected through close-in.

**Handoff:** AHJ/electrician → builder. **Record:** permit comments or approval, circuit plan, control/interlock notes, inspection hold points.

### Stage 5: procurement and substitution control

Procure the exact hood, blower, damper, termination, filters, controls, and any makeup-air components named in the design. Put a substitution rule in the scope: a different hood width, blower, duct collar, airflow rating, or filter configuration requires a new review. A visually similar model can have a different outlet, circuit, pressure curve, or makeup-air consequence.

The homeowner should receive the final manual before material is concealed. If the appliance changes from gas to induction, update the appliance and combustion record; if the hood changes from ducted to recirculating, update the route, filter, moisture, and AHJ record. Treat a substitution as a new decision input, not as a clerical change.

**Handoff:** supplier → builder and trades. **Record:** model numbers, revision date of manual, serial numbers when available, approved submittal, and delivery inspection.

### Stage 6: rough-in and pre-close inspection

Before insulation, drywall, cabinet closure, or ceiling finish, the builder holds a walkthrough. The team checks the route against the approved drawing, duct size and material, smoothness, seals, transitions, bends, damper orientation, termination, insulation and firestopping, makeup-air components, electrical box, framing, and access. Photograph the route with a ruler or dimension reference and mark the location on the as-built plan.

Do not use a photo to claim airflow, code compliance, or combustion safety. It is evidence of concealed geometry. Airflow, controls, and combustion tests require the appropriate professional or AHJ method.

**Handoff:** builder → HVAC professional, electrician, homeowner, and AHJ as scheduled. **Record:** pre-close checklist, photos, deviations, corrective actions, and close-in release.

### Stage 7: final commissioning and owner handoff

The hood is installed according to the manual, filters are fitted, the damper opens, the controls work, the selected speeds operate, the termination is unobstructed, and the homeowner sees how to run and clean it. The HVAC professional performs the required airflow or prescriptive verification and documents the result. If combustion appliances are in scope, the qualified professional completes the agreed safety test and report. The electrician verifies safe operation of the circuit and controls.

The homeowner receives the final hood manual, maintenance schedule, filter part numbers, duct and termination photos, model and serial numbers, permit or inspection record, airflow or compliance record, makeup-air instructions, and combustion report if applicable.

**Handoff:** trades → homeowner and ownership records. **Next decision:** accept, correct before occupancy, or record a qualified exception with a responsible party and due date.

## 8. Verify performance before the wall closes and during ownership

Verification must match the decision: a ducted system needs proof of route, termination, operation, and the required airflow or pressure basis; a recirculating system needs proof of filter configuration, capture operation, maintenance access, and a separate kitchen-ventilation plan. Neither architecture is verified by turning on the light or hearing the motor run.

### Verification before concealment

Use this homeowner-observable checklist during the pre-close walkthrough, with qualified professionals performing any restricted tests:

- The model and configuration on site match the approved submittal and manual.
- The appliance fuel and hood configuration in the decision log are current.
- The ducted route has the documented diameter, material, smoothness, length, bends, transitions, damper, and termination.
- The duct is independent where the adopted rule or design requires independence.
- The termination is outdoors and is not hidden in an attic, crawl space, or other prohibited interior space.
- Seals, weather protection, insulation, firestopping, and air-sealing details are complete and photographed.
- The filter, damper, makeup-air damper, control, and electrical connection have service access as required.
- The recirculating filter, if selected, is the exact part and can be removed without dismantling finished cabinetry.
- The hood is aligned with the cooking surface and installed at the manual’s height.
- The homeowner has been shown the normal and peak operating settings.
- The required airflow, prescriptive duct, or other local verification has an identified method and record.
- Combustion safety has a separate professional owner and report where relevant.

If a check is unknown, write “not verified” with an owner and deadline. Do not convert unknown to pass because the ceiling is ready for drywall.

### Airflow verification is not one universal test

The actual method may be a field airflow measurement, an approved prescriptive duct-sizing path, a fan-curve calculation, or another method required by the adopted code, program, or manufacturer. ENERGY STAR’s kitchen-exhaust guide describes both field-measured and prescriptive options for its program context and shows that a rater can verify certain duct arrangements from rated airflow, duct type, diameter, length, and elbow deductions. That [ENERGY STAR reference](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf) must not be generalized into a universal U.S. inspection method.

Ask the verifier to write:

- instrument or method;
- measurement location and operating speed;
- whether filters and dampers were in their normal operating position;
- pressure condition if measured or calculated;
- result in CFM or the applicable pass criterion;
- weather or house conditions that could affect the result;
- corrective action if the result misses; and
- date, professional, and project address.

For a recirculating hood, a CFM number does not prove outdoor exhaust because there is no outdoor duct. Verify the exact filter, airflow setting, filter indicator, access, and capture operation under normal cooking conditions. For odor or particle claims, do not invent a percentage removal result. The original worksheet’s limitation applies: it is not an airflow measurement or field test.

### Commission the controls and the pressure branch

Operate the hood at each selected speed. Confirm the backdraft damper opens without binding, the exterior termination is clear, the makeup-air damper or supply responds when designed to do so, and any interlock behaves as specified. Confirm that the controls do not leave a makeup-air heater, damper, or blower in an unsafe state when the hood is off.

The homeowner should ask the HVAC professional to explain what happens when the hood and other major exhausts run together. If the answer is “the house will find its own air,” the makeup-air and combustion branch is not resolved. The professional should state the operating assumptions and any restrictions on simultaneous operation. Keep that instruction in the owner’s manual, not just in a verbal walkthrough.

### Commission maintenance, not just installation

EPA instructs homeowners to clean the range hood’s grease filter routinely and to keep the hood running after cooking. The [EPA cooking infographic](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking) gives the 10–20 minute post-cooking guidance for an outdoor-vented hood. HVI explains that airflow, sound, power, and ducting are connected performance concerns; its [range-hood brochure](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf) also emphasizes certified ratings and a certified products directory.

Put these items in the maintenance record:

- hood grease-filter cleaning frequency and method;
- recirculating odor or other manufacturer-specified filter part number, change interval, and cost if applicable;
- inspection of the visible termination and damper;
- any duct cleaning or interior inspection recommendation from the manual or professional;
- makeup-air filter, damper, heater, and service interval if present;
- control, sensor, and interlock test frequency;
- combustion-appliance professional inspection interval where relevant; and
- symptom thresholds that require a service call, such as smoke escaping the canopy, a stuck damper, unusual noise, water entry, repeated filter alarms, or a CO alarm.

Maintenance access is a design requirement. If the homeowner has to remove a countertop, cabinet, or finished ceiling to replace the filter or service the damper, the rough-in passed a visual installation check but failed the ownership decision.

### Common failure cases and recovery actions

**Failure: the hood is chosen after cabinets are ordered.** The outlet, transition, opening, height, and service access do not fit. Recovery: pause cabinet fabrication, obtain the exact manual, and re-coordinate the hood and route. Do not cut a larger opening through structural framing without the responsible professional.

**Failure: the salesperson’s CFM is free-air.** The installed system is quieter only because it moves less air against the real route, or it is noisy because the route is restrictive. Recovery: request CFM at stated static pressure, the fan curve, and the route calculation. Mark unconditioned figures as incomplete.

**Failure: the duct starts large and narrows inside the cabinet.** The smallest diameter, transition, and fitting resistance govern the weak section. Recovery: show every diameter on the drawing and have the HVAC professional recalculate; the ENERGY STAR reference specifically warns that varying diameters are assessed using the smallest diameter in its table context. See the [reference guide](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf).

**Failure: elbows were omitted from the length.** The route looks within a straight-length allowance but has several direction changes. Recovery: count and locate every elbow and transition before framing; use the exact manual or professional calculation. ENERGY STAR’s program example deducts 15 feet per elbow in its specific table method, which demonstrates the need to count them but does not establish the universal deduction for every project.

**Failure: the hood terminates in an attic, soffit, or crawl space.** Moisture and grease are moved into a building cavity, and the route may violate the adopted rule. Recovery: stop close-in and keep the homeowner out of any unsafe or confined cavity. From a safe, accessible location only, document the visible condition with notes or photos; do not enter a confined space or disturb suspected contaminated insulation or materials. Assign the builder to isolate and correct the route, and have an appropriately qualified professional assess contamination or moisture damage and specify remediation before proceeding. Reroute outdoors and obtain the AHJ’s direction. EPA says kitchen and bathroom exhausts should vent directly outside. The [Virginia adopted-code regulation](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/) is a jurisdiction-specific example of why the project record must identify the governing code; do not use it to decide a different jurisdiction.

**Failure: recirculation is treated as equivalent to exhaust.** The homeowner expects moisture and gas-combustion products to disappear, but the filter returns air indoors. Recovery: restate the limits, add or design the separate required ventilation, revisit the appliance fuel, and ask the AHJ whether the ductless configuration is permitted. Do not call a recirculating filter an outdoor exhaust system.

**Failure: no filter access was drawn.** The filter is behind fixed trim or an appliance. Recovery: make access a close-in hold point and mock up removal with the actual filter before final cabinet installation.

**Failure: makeup air is discovered at inspection.** The hood is already installed, but there is no space for a damper, intake, control, or tempering. Recovery: do not bypass the requirement; return to the HVAC professional and AHJ, revise the route or hood operating point, and document any redesign before occupancy.

**Failure: the new range is induction, so the team drops all combustion review.** The range no longer burns gas, but a furnace, fireplace, water heater, or other appliance may still draft naturally. Recovery: update the appliance record but keep the whole-home combustion review assigned to the qualified professional. DOE’s induction explanation supports the appliance-specific distinction; it does not prove the entire home has no combustion risk. See [DOE](https://www.energy.gov/articles/making-switch-induction-stoves-or-cooktops) and [EPA](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling).

**Failure: the hood is substituted late.** The new unit has a different outlet, amperage, blower, filter, or airflow. Recovery: run the worksheet again, notify the designer, HVAC professional, electrician, builder, and AHJ as required, and preserve the close-in hold until the new submittal is accepted.

**Failure: the owner is told to “open a window” as the permanent makeup-air design.** A window strategy may be a temporary or code-specific exception, but it is not automatically a controlled, weather-independent solution. Recovery: ask the HVAC professional and AHJ to document whether the exception applies and what restrictions govern operation. Never use an open window to excuse an unresolved combustion-safety test.

### The final ownership handoff

At turnover, the homeowner should be able to answer six questions without opening a wall:

1. What is the exact hood and appliance model, and which configuration is approved?
2. What airflow and sound ratings were used, and at what pressure and speed?
3. Where does the duct terminate, and what route and damper were installed?
4. When does makeup air operate, if any, and who services it?
5. What filter is installed, when is it cleaned or replaced, and how is it accessed?
6. What test or inspection records prove the system was verified, and what limitation remains?

If the answer to any question is “the installer knows,” request the record before final payment or closeout, subject to the contract and applicable law. Ownership is the final handoff in the building decision: the system must remain understandable after the original trades leave.

### Originality brief: what this page adds and how to check it

Current answers usually offer generic ducted-versus-ductless pros and cons, product listings, or isolated code and indoor-air guidance. The missing decision is a jurisdiction-aware new-home rough-in release: what must be selected, designed, handed off, verified, and recorded before the wall or ceiling closes.

The original contribution is the **Source-derived range hood rough-in worksheet and decision matrix**. It can be checked by taking the same appliance manual, cooking pattern, hood ratings, route dimensions, AHJ response, and trade responsibilities and reproducing the hard stops, weighted comparison, illustrative formula, and sensitivity steps in this article. Its **method** is to extract decision inputs from EPA, DOE, ENERGY STAR, HVI, and accessible Virginia adopted-code text; compare both architectures by pollutant destination, pressure, sound, coordination, maintenance, and verification; then run an illustrative airflow-and-pressure sensitivity using explicit units, assumptions, and formulas. Its **limitations** are that it is not an engineering design, code determination, manufacturer instruction, combustion-safety test, airflow measurement, or field test; the actual AHJ, designer, HVAC professional, electrician, builder, and hood manual control the project-specific release.

### Sources and scope

The source records attached to this package preserve claim scope, host, access date, and URL. The technical and safety claims are based on the following accessible sources:

- [U.S. EPA: Strategies for Improving Indoor Air Quality While Cooking](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking) — cooking operation, outdoor exhaust, filter cleaning, and supplemental strategies.
- [U.S. EPA: Addressing Indoor Environmental Concerns During Remodeling](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling) — moisture, ventilation, duct sealing, combustion, and depressurization-safety scope.
- [U.S. Department of Energy: Making the Switch to Induction Stoves or Cooktops](https://www.energy.gov/articles/making-switch-induction-stoves-or-cooktops) — induction operation and appliance-specific combustion-pollutant context.
- [ENERGY STAR: Indoor Air Quality Features](https://www.energystar.gov/newhomes/features-benefits/indoor-air-quality-features) — certified-home kitchen exhaust and independent airflow-testing context.
- [ENERGY STAR: Ventilation Fans Key Product Criteria](https://www.energystar.gov/products/ventilation_fans/key_product_criteria) — static-pressure, airflow, sound, and certification context.
- [ENERGY STAR: Local Mechanical Exhaust Airflow Requirements for Kitchens](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf) — program-specific duct sizing and airflow examples.
- [Home Ventilating Institute: Range Hood brochure](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf) — voluntary certification, hood geometry, sound, airflow, and ducting context.
- [Broan-NuTone: Range Hood FAQs](https://broan-nutone.com/en-us/home/customer-service/range-hood-faqs) — manufacturer-specific non-ducted filter, recirculated humidity/smoke/heat, and replacement guidance.
- [Virginia Department of Housing and Community Development: Documents Incorporated by Reference, 13VAC5-63](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/) — accessible adopted-jurisdiction provisions for listed ductless range hoods and makeup air.
- [Virginia Department of Housing and Community Development: Codes](https://www.dhcd.virginia.gov/codes) — Virginia code effective date and state adoption scope.
- [Virginia Department of Housing and Community Development: Virginia Uniform Statewide Building Code](https://www.dhcd.virginia.gov/virginia-uniform-statewide-building-code-usbc) — Virginia local building-inspections enforcement scope.
- [International Code Council: Code Adoption Resources](https://www.iccsafe.org/advocacy/code-adoption-resources/) — model-code adoption and amendment scope.

Accessed September 8, 2026. The page does not claim that Virginia’s code, ENERGY STAR program guidance, HVI guidance, or any general source is the rule for a particular address. Confirm the actual adopted text, amendments, permit requirements, and exact hood manual with the project’s jurisdiction and qualified professionals.

## Evidence

- EPA advises that when a range hood vents outdoors, homeowners should turn it on whenever cooking, leave it on for 10–20 minutes afterward, cook on back burners when possible, and routinely clean the grease filter. [Strategies for Improving Indoor Air Quality While Cooking Infographic](https://www.epa.gov/indoor-air-quality-iaq/strategies-improving-indoor-air-quality-while-cooking-infographic). Scope: U.S. EPA text version of a residential cooking indoor-air-quality infographic; operational guidance for outdoor-vented hoods and supplemental strategies when outdoor venting is absent.. Accessed: 2026-09-08.
- EPA identifies cooking as an indoor moisture source and recommends kitchen exhaust ventilation directly to the outside; it explains that local kitchen fans remove contaminants and moisture from the room and increase outdoor-air ventilation. [Addressing Indoor Environmental Concerns During Remodeling](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling). Scope: U.S. EPA homeowner remodeling guidance covering moisture control, ventilation, combustion appliances, and residential kitchen exhaust.. Accessed: 2026-09-08.
- EPA says a gas range should use a properly sized range hood directly vented outdoors, warns that larger fans may depressurize a home, and recommends a worst-case depressurization test after combustion or ventilation equipment is installed. [Addressing Indoor Environmental Concerns During Remodeling](https://www.epa.gov/indoor-air-quality-iaq/addressing-indoor-environmental-concerns-during-remodeling). Scope: U.S. EPA residential combustion-safety guidance; the cited 100 CFM typical-range reference and test discussion are guidance, not a nationwide code rule.. Accessed: 2026-09-08.
- DOE explains that induction cooking creates heat in compatible cookware and does not produce the indoor combustion pollutants associated with burning gas, including nitrogen oxides, carbon monoxide, and formaldehyde. [Making the Switch to Induction Stoves or Cooktops](https://www.energy.gov/articles/making-switch-induction-stoves-or-cooktops). Scope: U.S. Department of Energy consumer article about induction technology and comparisons with gas and conventional electric cooking; it does not eliminate the need to control cooking particles, grease, odors, or moisture.. Accessed: 2026-09-08.
- ENERGY STAR says cooking emits particulates and humidity, and gas cooking also emits carbon monoxide and nitrogen dioxide; its certified-home guidance specifies a range hood or kitchen exhaust fan vented directly outdoors and independently tested for minimum airflow. [Indoor Air Quality Features](https://www.energystar.gov/newhomes/features-benefits/indoor-air-quality-features). Scope: ENERGY STAR certified homes and apartments program guidance; this is a program specification/context, not a universal U.S. building-code requirement for every home.. Accessed: 2026-09-08.
- ENERGY STAR ventilation-fan criteria use static-pressure reference conditions, require range hoods to meet the specification in each possible configuration, and describe tested airflow and sound metrics rather than relying on a free-air CFM number alone. [Ventilation Fans Key Product Criteria](https://www.energystar.gov/products/ventilation_fans/key_product_criteria). Scope: ENERGY STAR residential ventilating-fan specification page, including range-hood certification, static-pressure reference measurements, airflow, sound, and testing procedures.. Accessed: 2026-09-08.
- ENERGY STAR kitchen-exhaust guidance shows that allowable duct length depends on rated airflow, duct diameter, and whether the duct is flex or smooth; its table assumes no elbows and instructs the user to deduct 15 feet for each elbow and use the smallest diameter when diameters vary. [Local Mechanical Exhaust Airflow Requirements for Kitchens](https://www.energystar.gov/sites/default/files/asset/document/Kitchen%20Exhaust%20Reference%20Guide%20ENERGY%20STAR%20Single-Family%20New%20Homes_Rev12.pdf). Scope: ENERGY STAR Single-Family New Homes and Multifamily New Construction rater guidance revised September 15, 2022; the table is a program compliance option and does not replace the adopted code or hood manual.. Accessed: 2026-09-08.
- HVI says certified range-hood ratings are independently tested for airflow, sound, and energy; it also states that hood performance depends on cooking type and frequency and that duct width, bends, and length affect exhaust performance. [HVI Range Hood brochure](https://www.hvi.org/HVIORG/assets/File/public/publications/HVIRangeHood_4Feb08.pdf). Scope: Home Ventilating Institute consumer brochure and voluntary Certified Ratings Program explanation; HVI is an industry certification source, not the homeowner’s AHJ or the hood manufacturer’s installation manual.. Accessed: 2026-09-08.
- Virginia's incorporated-code regulation changes IMC Section 505.3 so that, in Group R buildings, a listed and labeled ductless range hood does not have to discharge outdoors when installed according to the manufacturer's instructions and when mechanical or natural ventilation is otherwise provided; the same official regulation changes VRC Section M1503.6 to require makeup air for exhaust hood systems capable of exhausting more than 400 CFM, with stated Virginia exceptions and automatic simultaneous operation requirements. [Documents Incorporated by Reference, 13VAC5-63 — Virginia Department of Housing and Community Development regulation](https://law.lis.virginia.gov/admincodeexpand/title13/agency5/chapter63/). Scope: Official Virginia regulation text for the Virginia Uniform Statewide Building Code's incorporated 2021-code amendments; the cited provisions are Virginia-specific and do not establish a nationwide rule or determine the code for another state, county, city, or township.. Accessed: 2026-09-08.
- Virginia's Department of Housing and Community Development states that the 2021 Virginia codes became effective January 18, 2024 and that Virginia adopted the 2021 I-codes as referenced in the Virginia Construction Code. [Codes — Virginia Department of Housing and Community Development](https://www.dhcd.virginia.gov/codes). Scope: Official Virginia Department of Housing and Community Development page describing Virginia's 2021-code effective date and state adoption context; it does not establish the local enforcement statement used in the article. Confirm the actual project jurisdiction, amendments, permit review, and AHJ interpretation.. Accessed: 2026-09-08.
- Virginia's Department of Housing and Community Development states that enforcement of the Virginia Uniform Statewide Building Code is the responsibility of the local government's building inspections department. [Virginia Uniform Statewide Building Code (USBC) — Virginia Department of Housing and Community Development](https://www.dhcd.virginia.gov/virginia-uniform-statewide-building-code-usbc). Scope: Official Virginia Department of Housing and Community Development page describing Virginia's Uniform Statewide Building Code and local enforcement responsibility; this is Virginia-specific and does not identify the AHJ for another jurisdiction.. Accessed: 2026-09-08.
- Broan-NuTone's official range-hood FAQ says its non-ducted filters trap some grease and odors from normal cooking while humidity, smoke, and heat are recirculated; it says charcoal-filter replacement normally depends on cooking frequency and type, commonly every three to six months, and that neglected filters lose their grease- and odor-catching effect. [Range Hood FAQs — Broan-NuTone](https://broan-nutone.com/en-us/home/customer-service/range-hood-faqs). Scope: Official Broan-NuTone manufacturer guidance for its range-hood products; the filter interval and performance statements are product-family guidance, not a universal rating for every manufacturer or model. The exact hood manual and filter instructions control.. Accessed: 2026-09-08.
- ICC explains that model-code language becomes law only after adoption by the appropriate state or local authority and that an adopting law may include amendments or changes; homeowners therefore must confirm the actual jurisdiction’s adopted code and amendments. [Code Adoption Resources](https://www.iccsafe.org/advocacy/code-adoption-resources/). Scope: International Code Council explanation of model-code adoption and incorporation by reference for governmental authorities in the United States and elsewhere.. Accessed: 2026-09-08.