Two commonly visible parts of an HVAC system are the condenser unit (the outdoor unit) and vents (the ductwork). However, your air conditioning system has another critical component that must be taken care of like other parts for the efficient and smooth functioning of your unit. That part is the air handler also called the air handling unit (AHU). Any issues with it can also cause efficiency and cooling/heating problems. You should consult HVAC repair services for any inspections and repairs.
What Is An Air Handler Unit?
As we mentioned an air handler is one of the major parts of an HVAC system because it works with the outdoor unit to cool or heat your house. It’s a large metal box usually installed horizontally and may appear like a furnace. Air handlers are commonly located in the basement, attic, or any other indoor part of your house.
A residential air handler contains an air filter, a blower fan and its motor, an evaporator coil, heating elements, and dampers. So, any issue with any of the above components would be an air handler problem.
Keep in mind that in mini-split air conditioners (ductless ACs), the air handler unit is the part that’s mounted on the wall that blows cool or hot air. It has air filters, an evaporator coil, a blower fan, a drain line, and temperature sensors.
The focus of this guide is the AHU of a ducted HVAC system. However, some problems and solutions may also apply to the air handler of a ductless air conditioner.
HVAC Air Handler Problems
Dirty Air Filters
We mentioned that AHUs have air filters so this means they require regular cleaning or replacement. Air filters are the first line of defense against airborne particles when unconditioned air enters the air handler for getting conditioned (cooled or warmed). As they keep the air and the other components like the evaporator coil clean, they become clogged with the particles they block, so they need to be cleaned or replaced.
Failure to do so would directly impact the airflow of the unit. You may notice weak airflow and less cooling or the unit running for longer periods before cycling off. This means the HVAC unit is working more to cool the house which will increase wear and tear and also hike the energy bills.
Therefore, clean the air filters once a month. However, the exact frequency may be different depending on how much you use the unit, the area where you live in, if you have pets, and other factors.
Damaged Or Obstructed Fan Blades
The blower fan regulates the airflow. If the fan blades are damaged or obstructed, they won’t perform their job properly leading to airflow issues and no cooling (in cooling mode). Fan blades are susceptible to damage as they rotate and if anything comes in contact with them, they may become bent or damaged. It could be debris or even critters.
If the fan blades are damaged, you may hear a rattling sound from the air handling unit. In that case, have an expert inspect the unit.
Malfunctioning Or Bad Blower Fan Motor
Another problem related to the blower fan is a bad motor. When the motor gives up, the fan blades don’t rotate at all resulting in no airflow and no cooling. Moreover, the motor gradually goes bad. During that time, the motor works slower than usual so the fan blades rotate slowly as well. Because of this, you would notice poor airflow.
Therefore, if there is reduced or restricted airflow, you should inspect the air filters, vents, fan blades, and the blower fan motor. In some cases, you may notice a burning smell that may be coming from the motor. However, it could be anything else as well so it’s better to call in an expert if you notice anything unusual or schedule an HVAC tune-up.
Moreover, there can be any other issue with the blower compartment so having a professional inspecting your unit is a good thing as they will inspect everything and suggest repairs and replacements.
Electrical Problems
The blower compartment has electrical wiring which can wear, corrode, or fray leading to the blower fan not working properly or not working at all. Inspecting electrical wiring can be difficult and risky so it should be left to HVAC experts. If there is a burning smell coming from the unit, you should turn it off immediately and call in a professional.
Condensation Leaks
When the air conditioner works to cool your house in the summer months, it produces condensation that flows to the drain pan that’s located under the air handling unit. This drain pan is then connected to a drain line. Any blockages, leakages, or damages in this entire system can cause condensation to leak out from the air handler. You would see puddles of water near the unit.
Therefore, inspect the drain pan and the drain line for blockages first. Clean them and if the issue is not resolved, look for a damaged drain pan or drain line.
However, keep in mind that another cause of water near the air handler unit is a frozen evaporator coil. We will explain this below.
Frozen Evaporator Coil
There is also a big coil in the air handler unit called the evaporator coil. It receives cool refrigerant from the condenser coil. When warm air from your house blows over the cold evaporator coil, the refrigerant in it absorbs the heat and leaves cool air to be pushed to your house via ducts.
However, if the evaporator coil freezes, it can’t cool the air properly leading to inefficient cooling. Moreover, as the ice on the evaporator coil freezes and thaws, it makes the air handler leak water.
The most common and easy-to-fix cause of a frozen evaporator coil is dirty air filters or not cleaning the air filter often. Only making sure to clean the air filters regularly depending on your usage can keep this problem from rearing its head. Moreover, a dirty evaporator coil can also lead to this problem.
Another cause could be low refrigerant levels. If an expert inspects the unit and the refrigerant is low, they will also look for possible refrigerant leakages. They will fix the leaks and then refill the unit with Freon.
Ductwork Problems
This is not an air handler problem, but it affects the air handler and the entire HVAC system. The ductwork is connected to the air handling unit so even if the AHU is working fine, any issues with the ductwork would lead to cooling problems. Common ductwork problems are dirty air ducts and cracked or leaky ductwork.
Dirty Air Handling Unit
We have discussed how you have to keep the individual components of the air handler unit clean like the air filter and evaporator coil. However, this would become difficult if the air handler is not taken care of regularly. So, make sure the location of the air handling unit is cleaned and so is the unit. This will help you avoid many problems.
Conclusion
Various problems can occur inside the air handling unit which signifies the importance of regular inspections and bi-yearly HVAC maintenance performed by certified air conditioning repair services Fairfax.
