Well you have your new air conditioning system installed and are very happy with your decision to make the investment. It was worth every penny and you have no regrets. To keep your new air conditioner working at peak efficiency for many years you need to begin a regular maintenance program that includes changing the filter.

This is one of the most important things you can do to get the best performance from your air conditioning and heating equipment. By changing your air conditioner filter and not allowing it to become dirty and restrict air flow you will enable the air conditioner to operate with minimal power consumption, reduce the risk of break downs and keep the amount of dust in your home at a minimum.

As the air conditioner filter or furnace filter becomes dirty it will gradually begin to restrict air flow through the system. Air conditioners are designed to have a certain amount of air flow for each ton of cooling. Four hundred cfm per ton to be exact. As the filter becomes dirty it will reduce air flow to the point that air flow falls below these design parameters.

When this happens it creates the effect of low load conditions on the air conditioner and the operating pressures begin to drop. Under normal conditions the evaporating temperature in the system will be above 32 degrees Fahrenheit.

Because this evaporating temperature is below the room temperature, and the dew point temperature, condensation forms on the evaporator coil from the air as it passes through the evaporator coil. This is good because it helps maintain a comfortable humidity in your home. The condensation drips from the evaporator and drains away from the unit.

When an air conditioner filter becomes dirty enough to reduce air flow, it has the same effect on the system as low load conditions. When air conditioning equipment operates under low load conditions the evaporator coil can ice up. Once ice begins to form, the problem gets progressively worse and eventually a block of ice forms around the evaporator and there is virtually no air flow.

The ice forms because as the heat load on the system diminishes the evaporating temperature in the evaporator begins to drop. When the evaporating temperature drops below 32 degrees Fahrenheit frost begins to form on the evaporator coil.

As frost begins to form it further reduces the amount of air flow and the situation becomes worse. As mentioned before when equipment is allowed to operate like this, eventually the evaporator will become a block of ice and the unit will have to be turned off and allowed to thaw. If this situation occurs it can also damage the evaporator to the point where it begins to leak refrigerant and may even have to be replaced, which will be very expensive.

There are other conditions that can cause these symptoms but this is one of the most common. Frost forming on one of the lines coming out of the air handler is an indication of low air flow among other things. The first thing to do is check your air conditioner filter before calling for service.