What is an Air Handling Unit?

If you have a split system air conditioner or heat pump, you are aware of the fact that you have both indoor and outdoor units. The outside unit houses the compressor, one of the most expensive components of the system. Your inside unit houses the blower along with evaporator coils, a drain pan and the air filter. This is known as the air handling unit, and careful maintenance is important for optimum system performance.

How Do Air Handling Units Work?

Your air handler may be freestanding, or it may be enclosed. It connects to your air ducts, serving as the means of moving air through the circuit and into different parts of your home. The blower is operated by a motor, and in modern systems, multiple speeds may be available to provide more or less intense heating and cooling action.

An air handling unit that is part of an AC or heat pump split system also manages the heat transfer process in your home. As refrigerant moves through the coils in the unit, it gives off or absorbs heat, leading to a change in the temperature of the surrounding air. In an AC unit, the function of the coils is to absorb heat so that cool air can be distributed through the home. A heat pump can also transfer heat from these coils to the surrounding air to heat the home.

Indoor coils also contribute to dehumidification during summer cooling months. As the coils absorb heat, moisture in the air condenses, pooling and dripping from the coils into a drain pan. This condensate liquid is directed out of the home through drain lines.

Maintaining Your Air Handling Unit

Pre-season maintenance of your heating and cooling equipment is important for efficient operation. The air handling unit is prone to a buildup of dirt because of the constant movement of air through your system. Although your air filter catches much of the airborne debris, as it becomes clogged, more of the material can make its way into the air handler. This debris can settle on your coils, inhibiting the heat transfer process significantly. Dirty indoor coils can add as much as 20 percent to your energy costs for HVAC activity, making coil cleaning a significant money saving strategy. During your preventive HVAC service, your technician will also check moving parts in your blower, lubricating as needed. Additionally, your drain pan will be cleaned so that liquid condensate doesn’t back up and overflow.

Upgrading Your Air Handler

The failure of some components in your unit can be addressed with replacement parts. In some cases, however, it’s better to replace the entire unit. If you are obtaining poor performance from your AC or heat pump, you can consult with your contractor to evaluate whether an upgrade is warranted. It’s common to replace both the indoor and outdoor units at the same time so that parts work together. However, it’s important to discuss the options with your HVAC service representative.

W A Air Conditioning can assist you in dealing with dirt in your HVAC system. We can also help in evaluating the performance and life of your equipment. Whether you need a repair or a tune-up, our technicians are ready to help when you contact our office.


January 22, 2014 5:49 pm