Duct Boosting - How to increase air flow in ducts

What is the problem ?

For one reason or another many homes have been built with undersized ductwork. Remote rooms that are just plain too hot or cold... What's going on here is that pressurized air (from your furnace, air handler) will take the path of least resistance and not travel to those distant rooms.

What can you do ?

First rule: Cheap things first! Most furnaces or air handlers have multiple speed connections (taps). Perhaps you can raise fan speed on the unit. If you do have too much airflow on the shorter duct runs, you will need to throttle back that air. Dampers located on your grilles or registers are not very useful for this purpose and can cause a lot of noise if used.  Obviously this approach may not work for you and does require some labor.

Booster fans.

Inline Air Booster Fans

Air booster fans are used inline when the main fan does not have enough capacity to blow air through long or convoluted duct runs

Room-to-Room and Register Boosters

Room to room and register boosters are simple to install fans designed to boost airflow.

Pressure (Air) Balancing

Relieve pressure build up in the home by allowing the movement of air from one room to the next. Wall and door air pathways.

Pressure Switches

Pressure switches for gases (usually for air) and liquids. Proving switches.

Current Switches

Current switches used to activate booster fans. Also used for boosting clothes dryers.

Exhaust Fan Controls

Electronic timers, humidity switches, and fan speed controls.

AV Closet Cooling

Fan system designed for cooling AV equipment rooms, closets, and larger enclosures.

Draft Inducers and Chimney Fans

These fans can be used to improve the draft of a wood fired chimney.

Power Venters

Used for side wall venting residential/light commercial natural gas, LP or oil fired equipment including: furnaces, boilers, water heaters and unit heaters.

Booster Fans


We have several varieties and brands of booster fans. How do you know which one will work for you? As you would expect, there are quality and performance improvements which come with higher prices (also said as .."you get what you pay for")


Please take a look at our how-to aritcle for more info:



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