One of the simplest, and often neglected maintenance issues for air conditioners and heat pumps is the regular changing of the return air filter. By not changing the return air filter on a regular basis, the filter will clog and obstruct the return air flow to the indoor coil. The obstruction will slow down the air across the coil, making the air colder, eventually leading to the freezing of the indoor coil.
By simply changing the air filter on a regular basis, the home owner can make sure the return air flow is sufficient and prevent nuisance freeze-ups. The air filter manufacturer will recommend the interval for changing the filter.
Air filters can be made in any size and are rated by their "minimum efficiency reporting value" or "MERV". The higher the MERV of the air filter, the greater the percentage of particulates that are captured on each pass through the filter. The MERV scale goes from 1 to 16. Installing the highest MERV air filter is not recommended for your air conditioner or heat pump because it will act as an obstruction to the return air flow. We recommend installing an air filter with a MERV rating of 5 to 8, unless the system has been designed to accommodate a higher MERV air filter. Please give us a call if you have any questions regarding air filters, or if you would like to place an order for an air filter that will work for your system.