A: Yes. It can cause multiple problems in both heating and cooling modes. Dirty filters reduce efficiency. They also cause furnaces to overheat; A-coils to ice up; and blower motors to burn out.
Q: Does a high-efficiency air conditioning unit cool more than a standard-efficiency one?
A: No. The size of the unit—not the efficiency--determines the amount of cooling it can do. The efficiency of the unit refers to the amount of energy it uses, not the amount of cooling it produces.
often should I change my filter?
house is different. But for most, every
3 - 4 months. Pets, smoking, number of people in and out of the house, and fan
run-time, all affect the frequency of your filter change-out.
SEER: Seasonal Energy Efficiency Ratio. Measures
cooling efficiency, calculated by the cooling output for a typical cooling
season, divided by the total electric energy input during the same time-frame. Basically,
the higher the SEER rating, the greater the efficiency. A/Cs and heat pumps are
rated in SEERs.
EER: Energy Efficiency Ratio. Cooling
output divided by electrical power input. Typically determined by a set outside temperature and a set inside air
temperature, and a 50% relative indoor humidity. Just like SEER, the higher the
EER, the more efficient.
AFUE: Annual Fuel Utilization
Efficiency. Gas furnace rating. It’s a unit’s efficiency at converting fuel
into heat by projecting average thermal efficiency for a full heating season. 80%
would be standard; anything above 90% is considered high-efficiency.