Most Common Issues of exhaust Fan in HVAC System

HVAC System aka Heating & Ventilation Air Conditioning System which is highly effective for the modern era building room or zones temperature control on a different levels.  Exhaust Fan known as one of its most important components whose work is defined to throw dustful and heated air outdoors the surroundings. For Some Reasons few of time it faces working issues and our this blog was highly dedicated to the most common issues of exhaust fan in hvac system and precaution, hvac solution to resolve these all problems.

Major Problem with Exhaust fan by Human Error

• Ignorance: Irresponsible Behavior to Ignore Unusual Noises which came from the Fan and System.

• Maintenance gap: Sometimes the user can’t make a call for the service partner for an accurate guidelines giving period that at some point the fan and other components of your HVAC system could face some problems.

• Less Skilled Technician: Many People or authority contact local technicians but in major cases technician can’t pass the required skills for maintenance and after a few days components of hvac include exhaust fan also causes error.

Reason of Error in Exhaust Fan by System Own

• Mechanical Blockages/Restrictions: A blocked or clogged filter, grease in the duct or duct obstruction may cause the fan to run outside its specified design such that the system will shut down or alarm.

• Electrical Problems: Cause could be a tripped circuit breaker, blown fuse, loose wiring, or power supply imbalance, causing the fan to stop, or operate abnormally. Heat can also be an issue with motors potentially being overloaded by heat causing a protection device to switch the fan off until it cools.

• Faults of Control System: In case of failure in the control system on timers and humidity sensors, and relays, contactors, the automatic control systems can incur errors. As an illustration, a stuck relay or a malfunction sensor may be encountered which might make the fan not run or still run continuously.

• Motor Failure or Fan Overload: An undersized, damaged or overloaded (more current than is specified) fan motor can cause tripping of in-built overload protection or external overload relays thus causing a system error.

• Vibration or Mechanical Failure: We have also seen that excessive vibration caused by unbalanced or out of balance fan blades and fasteners, misalignment, loose fasteners/bearings can cause operating sensors or mechanical devices can produce damage leading to system shutdowns, and errors.

• System Design or Installation Factors: Insufficient duct size, constrictive fittings, system installations, i.e., excessive duct assembly or collar length, can result in high static pressure or low airflow with resultant error conditions indicated by the system.

Solution to Prevent Exhaust Fan by Unusual Errors

Unusual errors in exhaust fans can be avoided with apt installation, as well as maintenance and thorough observing strategies. The following is the way of avoiding the risk of unknown failures to its minimum:

1. Constant cleaning and check-up

   1. Wash blades, grills and filters fortnightly or once or every 4-6 weeks to eliminate dust, grease and other contaminants that may create a blockage of air and over straining the motor.

   2. Clean and survey ductwork at least two times in a year to remove impairments and assure free flow of air and avoid moisture or boldness.

   3. Old dust, spiders, and other obstructions should be checked and swept out of ventilation and fans.

2. Planned Preventive Maintenance

   1. To minimize the friction of the motor and the bearings, use motor oil and bearings oil as directed by the manufacturer.

   2. Check belts (on belt driven fans) and adjust tension as well as replace them if worn or damaged.

   3. Put all the electrical connections tight and inspect whether they are overheating, corrosion or loosely running wires.

   4. Insulation resistance Measure test motor insulation resistance at regular intervals using a calibrated megohmmeter.

3. Proper Installation

   1. Fan must be at the appropriate size to be used in the space or application, as this will result in faulty performance and heat as well as an early end to its life due to insufficient or excessive sizing.

   2. Fan should also be mounted in a rigid, vibration-isolated position to avoid the over vibration and mechanical fatigue.

   3. To reduce stress and transfer of vibration use flexible attachments between fan and ductwork.

4. Timely Troubleshooting

   1. It is best to deal with abnormal sounds (squealing, grinding) promptly, as they often indicate a worn-down bearing, or misalignment.

   2. Examine out-of-control behavior, including unexpected shutdown or constant running, by inspecting thermal overloads, sensor fault or timer errors.

   3. In case the fan does not power up check and reset circuit breakers and inspect switches and wiring.

Read Also:- How to Fix the Exhaust Fan in VRV Outdoor System

Conclusion

Exhaust fans also play a crucial role in HVAC operation but are easy to fail due to human errors (disregard of noise, maintenance not done) or systems errors (clogging, electric faults, motor failure). Avoiding such frequent issues depends on the policy of prevention: ensure that the unit is cleaned on a regular basis, professionally checked periodically, properly installed, and investigated in case of any loud or strange noises or behavior to guarantee adequate, predictable performance.