Duct Fans

Duct fans improve airflow through HVAC ductwork, helping rooms heat and cool more evenly, reducing humidity, and cutting energy waste from struggling systems. Whether you’re boosting a long duct run, clearing steam from a bathroom, supplying fresh air to a workshop, or venting a grow tent, a properly sized duct fan can stabilize temperatures, reduce odors, and enhance indoor air quality.

Common styles include inline duct fans, duct booster fans, mixed-flow fans for quiet performance, and centrifugal fans for higher static pressure. Sizes typically range from 4 to 12 inches to match round or rectangular ducts, with airflow ratings from 100 to 1000+ CFM. Look for EC (electronically commutated) motors for high efficiency and precise speed control, or robust AC options for cost-effective upgrades. Noise matters too: mixed-flow designs and insulated housings help keep sound levels low.

How to choose the right duct fan:
- Match fan diameter to duct size to prevent turbulence and loss.
- Size by required CFM and static pressure from filters, grilles, and long runs.
- Check noise ratings (dBA/sones) if installing near living or work areas.
- Consider controls: speed controllers, thermostats, humidistats, or smart automation.
- Useful features: backdraft damper, vibration-isolating mounts, quick-release clamps, thermal protection, and UL/ETL listings.
- Construction: galvanized steel or ABS; sealed bearings and IP-rated housings for humid spaces.

Installation tips:
- Place the fan mid-run or near the problem room for best pull.
- Keep duct runs straight; avoid tight elbows and restrictions.
- Use flexible couplers, secure supports, and seal joints with foil tape or mastic.
- Balance supply and return airflow to avoid pressure issues.
- Maintain by cleaning blades and grills and checking bearings.

Ideal for bathrooms, kitchens, attics, crawlspaces, server closets, and home offices, duct fans provide targeted ventilation and reliable HVAC airflow improvement.