I'm not a construction, air conditioning or utility expert. I do have personal experience in owning homes and attempting to keep utility costs at a minimum. I had a discussion with a neighbor the other day when his air conditioner went down during the 100 degree temperatures. We checked the coils and they weren't frozen. The compressor kicked on, no frozen coils, but there was no cooling or air circulating in the house. My best guess- the blower was out. It was easy for me to diagnose considering mine had gone out last year. On a side note, if you have a unit in the attic check the drip pan. If the pan is filled with water, the drain is clogged and needs to be cleaned. Something you can probably do on your own.
The conversation with my neighbor turned to electric bills. He stated his bills in this weather ranged in the low $200's! Mine range in the low $100's. Our houses are approximately the same size - 1800 - 1900 square feet. Don't get your hopes up if you own older homes. These are homes that are less than 10 years old and are fairly energy efficient. My point goes to thermostat settings. Newer homes generally have split systems or dual thermostats. When I asked what he had his thermostat settings at he said "a constant 73." I asked, "upstairs and down?" The answer- "Yes." My neighbor has a downstairs master bedroom, spends the majority of his time downstairs and he keeps his upstairs thermostat at 73 degrees? Heat rises? Of course it does, but why would you keep an area you spend little or no time at 73 degrees? Again, I am no expert, but I believe the recommendation for thermostats is 78 degrees. Not that I could live with that!
Back to my point. If you have a split or dual system,evaluate your thermostat settings on each level. If not, when you're not home consider raising the thermostat. Each degree you raise your thermostat can save you as much as 2% on your monthly electric bill.
Just my saving 2 cents.
Agent Owned Realty