Commercial Exhaust Fan Repair and Maintenance

Exhaust fan issues commonly present themselves as loud noises while operating, complaints of spaces being to hot or sudden suction drops. Ensuring your exhaust fan is working properly allows fumes to leave the area and ensure the safety of those in the space. In this article we will give you a maintenance checklist and things to look out for when considering commercial exhaust fan repair.

Commercial Exhaust Fan Repair

By listening for rattling or unusual tones you may be able to spot issues before the system fails. Excessive vibration or a velocity/pressure drop are another sign that something is not right. In any case, when the clattering or banging begins, it’s time to call in the experts.

Note: If the exhaust system is not turning on, start by checking the circuit. If it isn’t a circuit, you may have a more serious issue that should be diagnosed professionally.

Some common issues we see in exhaust fan are:

1. Fan bearing failure – If your fan is louder than normal, this is usually due to bearing failure. Ensure surface temperature is within range. Then check oil rings and watch for excessive end play. Greasing the bearings regularly helps prevent these issues.

2. Worn Or Broken Belts: This is one of the most common issues. Check belt tension (should have about 1″ of play). Ensure sheaves and couplings are tight and don’t have excess play. If there is excessive play in the fan pulley, it may need to be replaced.

3. Motor Failure: Occasionally the fan’s motor may have completely burnt out.

Commercial Exhaust Fan Maintenance

All hoods should have preventive maintenance performed on a regular basis. These units are often overlooked even though they some of the most used pieces of equipment in many facilities.

For Exhaust Fans up to .25 hp you should perform the following steps quarterly:

• Check/clean fan assembly
• Lube fan bearings
• Lube motor bearings
• Check belts & sheaves – adjust as applicable
  

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  Tighten all nuts/bolts/mounting hardware

• Check motor mounts and vibration pads
• Check motor volts/amps
• Inspect and tighten all electrical connections
• Check fan operation
• Check structural integrity of assembly

For exhaust fans up to .75hp perform the following procedures semi-annually:

• Check blade pitch operation where applicable
• Check rotary union where applicable
• Inspect/lube blade links where applicable
• Inspect/lube spherical bearing where applicable
• Lube spider hub assembly where applicable
• Check/clean fan assembly
• Lube fan bearings
• Lube motor bearings
• Check belts & sheaves – adjust as applicable
• Tighten all nuts/bolts/mounting hardware
• Check motor mounts and vibration pads
• Check motor volts/amps
• Inspect and tighten all electrical connections
• Check contactors/relays, etc.
• Lube/adjust associated dampers
• Check fan operation
• Check structural integrity of assembly

Why Clean Commercial Exhaust Fans?

Aside from the obvious reasons, like ensuring proper operation and prolonging the equipment’s’ life, there is another reason. That is fire safety. If your exhaust fan is located in a cafeteria, kitchen, restaurant or catering facility, you need to have that hood cleaned regularly.

The National Fire Protection Association’s NFPA 96 requires trained and certified personnel to clean restaurant kitchen hoods and exhausts on a regular basis. (NFPA 96-11.4)

“Upon inspection, if found to be contaminated with deposits from grease-laden vapors, the entire exhaust system shall be cleaned by a properly trained, qualified, and certified company or person(s) acceptable to the authority having jurisdiction in accordance with Section 11.4.”

Preparing Commercial Exhaust Fans For Winter

For exhaust fans that are used to reduce heat, they are often not necessary in the cold winter months. When this is the case, you will want to winterize your exhaust fan. This often involves installing covers on the outside of the unit and installing foam on the inside. Be sure to remove the cover and insulation before starting the system back up again in the spring.

We Can Help

We can repair all types and sizes of blowers, fans, and exhaust systems. Whether they are roof mounted fans, sidewall exhaust fans, or kitchen ventilation systems, we can help! Call us at 1-800-237-3141, email sales@rasmech.com, chat with a support agent, or contact us online.