Ventilation fans in modern livestock buildings, greenhouses and crop storage barns are an efficient way to
exhaust moist air and provide summer cooling. But just because a fan is turning doesn’t mean it’s moving
air efficiently. Here are some tips to improve efficiency.
Cleaning increases performance. Be careful not to knock blades out of balance.
Keep fan blades and shutters clean, to reduce
friction and move more air. If fans are not cleaned, the accumulated dirt increases the resistance to air flow,
cutting efficiency by up to 40%. This is particularly a problem in animal buildings. The farm operator loses in
two ways -- less air will be delivered for the same amount of electricity, and animal production will suffer
due to fowl air, and summertime heat stress.
Perform maintenance checks and cleaning of fans every two months (monthly for poultry houses). Look for:
(1) Belts that are too loose, too tight or misaligned;
(2) Shutters that won’t open fully due to dirt or lack of lubrication;
(3) Fan blades with a film of dust or caked-on dirt;
(4) Weeds and other obstructions near the fan discharge that blocks airflow.
To clean fan blades and shutters, first disconnect power to the fan; this is a critical safety step. Place a lock or sign on the switch so no one accidentally turns on the circuit. Use compressed air or a stiff brush to remove dust buildup. If moisture has caused caked-on dirt, try a warm detergent solution or a plastic putty knife, but remember fan blades can be bent easily. Wipe off the motor too, which keeps it running cool and extends its service life. Check all electrical wiring for rodent damage, loose wires, or other electrical hazards. Reattach guards, screens and covers before turning the power back on.
Many of these same efficiency tips apply to fans in non-farm applications.
Warehouses, machine repair shops, dry cleaners, and other businesses use fans to supply fresh
air for summer cooling, and can benefit from the same maintenance tips provided here.
Information on agricultural fan efficiency is available on this site. RERC has two helpful books:
Agricultural Ventilation Fans: Performance and Efficiencies lists actual fan performance ratings
for hundreds of fans tested by the University of Illinois. A second 8-page booklet, Agricultural
Ventilation Fans: Selection and Maintenance describes how to use the listing and explains
step-by-step cleaning and maintenance tips to make existing fans more efficient.
Keep fan blades and shutters clean, to reduce
friction and move more air. If fans are not cleaned, the accumulated dirt increases the resistance to air flow,
cutting efficiency by up to 40%. This is particularly a problem in animal buildings. The farm operator loses in
two ways -- less air will be delivered for the same amount of electricity, and animal production will suffer
due to fowl air, and summertime heat stress.