Why Changing Your Air Filter Regularly Is Important!
Last night on my drive home, a friend called me to ask my opinion on his upstairs A/C unit which was no longer blowing cold air, in fact there was very little air movement at all. My first questions was “have you changed your air filter recently?”
This is a common summer problem for residents in the humid south. When your air conditioner is working properly, a refrigerant is sent to a small “radiator” by the air handler (fan) very similar to the one on cars. This refrigerant is very cold and as a result performs two functions: 1) it cools the air passing through it as heat moves from the warmer air to the colder refrigerant (remember that heat always moves from hot to cold) 2) moisture in the air is removed through condensation. As the air from your house passes over the cooler radiator fins, the moisture suspended in the warmer air reaches the dew point as it cools and condenses to fluid on the metal surface of the fins, then drains out from the system through the condensate lines (this is the water dripping out of your A/C unit lines in the summer).
The proper functioning of this cycle depends entirely on air moving across the “radiator”. If the air flow is restricted (e.g. dirty air filters) then sufficient heat is unable to be transferred to the refrigerant, the radiator then gets too cold and the condensation which forms on the fins begins to freeze rather than drain. When this “radiator” is sufficiently blocked by the ice, cold air is no longer able to get through and your system stops cooling the house. In some cases this can damage the system. If it’s caught early enough, the system can usually recover by simply shutting the system down and letting the ice melt, but remember to change the filter!
In my friend’s case, he shut the system down, changed the filter and waited 2 hrs. Afterwards everything started working fine again.
