For most of us, our central cooling system represents the single greatest cost on our summertime utility bills. Often times it makes up to half our bill or more. What are some of the things you can do to reduce your cooling costs this summer?
As noted on a previous post, the single most important thing you can do is keep your air filter clean. This ensures proper air flow throughout the system. Another key item is to keep the area around the outdoor unit free from bushes, branches, weeds, etc. that can prevent efficient air flow through the condenser coils. Your unit needs unrestricted air flow around it to ensure efficient operation. Also, you can wash out the visible condenser coils by turning off the power to the unit at the circuit breaker or at the wall mounted disconnect switch, and flushing out the dust and dirt that collects between the coils. It’s amazing, sometimes, how dirty the water can be that comes out from between the fins.
Another thing to look for is obvious signs of air infiltration coming around leaky doors and windows and address with appropriate weather stripping and caulking. Also, if your duct system is accessible, it’s good to inspect the ductwork for air leakage while the system is running and seal as needed with duct tape or mastic.
A good way of measuring to see if your air conditioning system is operating efficiently is to use a thermometer and measure the air temperature difference between the return air grill (where the air goes back to the unit) and the supply air register closest to the unit. You should be able to get a temperature difference of 18 to 24 degrees F. If it is lower than this, it may indicate that your system is low on Freon and needs to be serviced. If it’s higher than this, it may indicate an air flow problem such as a dirty evaporator or a crushed duct.
An interesting note is that if your cooling system is just 10% low on Freon, it can cost 30% more to operate, and you don’t even realize it is low. It still cools, but takes 30% longer to do it. It will show up on your utility bill though. So, there are things you can do to make sure your system is operating efficiently.