How to size an AirZone bath fan (CFM by bathroom size)
Size an AirZone fan by airflow, not by housing size: aim for enough CFM to replace the room's air about eight times an hour, which for a standard eight foot ceiling works out to roughly one CFM per square foot of floor area. The Home Ventilating Institute publishes the eight air changes per hour standard this rule is based on. Match your bathroom's square footage to the chart below, then round up to the next AirZone tier.
- Bathroom up to 50 sq ft needs 50 CFM: AirZone S50, SNP50.
- 50 to 80 sq ft needs 70 to 80 CFM: AirZone S70, SE80P, SES80.
- 80 to 100 sq ft needs 90 to 100 CFM: AirZone SE90P, SNP100.
- 100 to 110 sq ft needs 110 CFM: AirZone SE110P, SE110PH.
- 110 to 150 sq ft needs 150 CFM: AirZone SE150P, SEPD150.
- Over 150 sq ft needs 200 CFM and up: AirZone SED400, SED500, sized by fixture.
For a bathroom over 100 square feet, the Home Ventilating Institute recommends adding CFM by fixture instead: about 50 CFM for each toilet, shower, or bathtub, and 100 CFM for a jetted tub, then total them to find the fan size.
How quiet are AirZone fans? Sones explained
AirZone fan noise is measured in sones, a loudness unit where a lower number means a quieter fan, and anything at or below about 1.0 to 1.5 sones reads as quiet in a normal bathroom. For reference, 1.0 sone is close to the sound of a quiet refrigerator. AirZone's positioning rests on ultra quiet AC and DC motors built for continuous, low noise operation. Check the sone rating on each product page, since it varies by CFM class and motor type.
AirZone fan types: fan only, light, humidity, motion, and high CFM DC
AirZone builds several configurations off the same quiet fan platform, so choose by the job rather than the model name: a plain exhaust fan, a fan with an LED light, a fan with a humidity sensor, a fan with a motion sensor, a fan, heat and light combination, or a high CFM DC motor unit for larger rooms.
- Fan only for a bathroom that already has separate lighting and just needs quiet exhaust: SE Select and SES Slim Line models.
- Fan with LED light for one ceiling grille that both lights and ventilates: fan and light models.
- Fan with humidity sensor that runs automatically when humidity rises, then shuts off on its own: PH models such as SE110PH.
- Fan with motion sensor for guest and powder rooms that switch on when someone enters: M models such as SEPD140MH.
- Fan, heat and light for cold bathrooms wanting warmth, light, and ventilation in one fixture: fan, heat and light.
- High CFM DC (Supreme) for large bathrooms and light commercial restrooms: SED400 and SED500.
AirZone also sells replacement parts, including LED light kits, backdraft dampers, and motors. Because AirZone fans use a plug and play design, you can add a sensor, a light kit, or a controller to an installed fan without replacing the housing.
Reading AirZone model numbers (the SE series)
AirZone model numbers follow a readable pattern: a series prefix, a number that reflects the fan's CFM class, and letter suffixes that flag added features such as a humidity sensor or an LED light. The prefix identifies the platform: SE is the AC motor Select series, SES is the shallow Slim Line series, SED is the DC motor Supreme series, and SEPD covers the DC Select and 4 in 1 models. The number reflects the CFM class, so SE110 moves about 110 CFM and SED400 sits near the top of the range for large spaces. Four worked examples:
- SE110P: AC motor Select fan, 110 CFM class, premium efficiency, no light or sensor.
- SE110PH: the same 110 CFM fan with a humidity sensor added.
- SE110PL2: the same fan built with an LED light instead of the sensor.
- SED400: a DC motor Supreme fan for high airflow in a large bathroom.
Some models carry a trailing letter such as N, which denotes the light kit generation or housing variant on that model's catalog sheet.
Venting and installation basics
An AirZone fan must vent to the outside through rigid or approved duct, never into an attic, soffit, or wall cavity, where the moisture it removes would collect and cause the mold you installed the fan to prevent. AirZone AC fans use a detachable collar sized for 4 inch and 6 inch duct, with a built in backdraft damper that stops outside air flowing back in. Terminate the duct outdoors, away from the roofline and at least three feet from windows and other openings. AirZone fans run on 120 volt line voltage, so a licensed electrician should handle the wiring and follow your local building code. Many AirZone models are ETL listed for installation over a tub or shower on a GFCI protected circuit.
AirZone vs Broan, NuTone, and Panasonic
AirZone is a value focused, ultra quiet alternative to the household bathroom fan names Broan, NuTone, and Panasonic, which is why it tends to appeal to contractors and remodelers pricing a job rather than shoppers loyal to a brand. Broan and NuTone dominate consumer search, and Panasonic is known for its WhisperSeries efficiency, but AirZone competes on the core specs that matter in a bathroom: HVI certified airflow, ultra quiet AC and DC motors, and ENERGY STAR listings, at a spec grade price point. For trade buyers, Lumera stocks 47 AirZone SKUs and supports trade account pricing and job quantities that a homeowner focused big box guide does not address.
Frequently asked questions
What size AirZone fan do I need?
Size an AirZone fan by CFM, targeting roughly one CFM per square foot of floor area for a standard eight foot ceiling, which follows the Home Ventilating Institute's eight air changes per hour standard. A 90 square foot bathroom needs about a 90 CFM fan such as the SE90P. For bathrooms over 100 square feet, add CFM by fixture instead.
Are AirZone fans quiet?
AirZone fans are built around ultra quiet AC and DC motors, and most bathroom models rate at or below about 1.0 to 1.5 sones, the range that reads as quiet in everyday use. The exact sone rating is printed on each product page, since it changes with the fan's CFM class and motor type.
Do AirZone fans come with a light or heater?
AirZone offers fan only models, fan with LED light models, and combination fan, heat and light units, so you can run one ceiling fixture instead of three. A GU24 LED light kit also converts many SE and SED series fans into a fan light after installation, thanks to AirZone's plug and play accessory design.
What is a humidity sensor fan and do I need one?
A humidity sensor fan, marked with an H in the model number like the SE110PH, has a built in humidistat that turns the fan on when bathroom humidity rises and shuts it off once the air dries. It suits any bathroom where people forget to run the fan, since it controls moisture and mold on its own.
Can I install an AirZone fan myself?
AirZone fans run on 120 volt line voltage, so a licensed electrician should handle the wiring and follow your local building code. The housing mounts to ceiling joists with adjustable hanger bars, and many models are ETL listed for installation over a tub or shower on a GFCI protected circuit.
Where should a bathroom fan vent to?
A bathroom fan must vent to the outside through rigid or approved duct, never into an attic, soffit, or wall cavity where trapped moisture causes mold. Terminate the duct outdoors, away from the roofline and at least three feet from windows and other openings, and rely on the built in backdraft damper to block cold air return.
