You are absolutely correct to turn the temperature up when you aren't home. However, there is a limit to how much warmer the thermostat should be turned up. We recommend not turning it more than 7-10 degrees warmer than the temperature you would desire when you are home. Otherwise, the unit will end up running longer than to cool that 10+ degrees than it would have if it had been left at the original temperature all day.
A couple of tips for extra energy efficiency: Change the filter. A dirty filter is not only hard on the indoor blower motor, while decreasing air flow, it also affects the outdoor condenser. It allows liquid freon to be carried back to the compressor (instead of vapor), damaging the compressor.
Also, to save a bit on the electric bill, wash the outside condenser every month or 2 during the a/c season! The a/c sucks in air from the sides (along with dirt and debris) and blows it out the top, cooling the unit. Spray it out with a hose and wash the dirt and debris out of the "fins". Doesn't matter if the unit is running, it is made to take some water. The cooler it runs, the less energy it uses.
Lastly, make sure it is actually cooling properly! It is going to use the same amount of electricity when it runs whether it cools the house or not. At the outside unit, there are 2 copper lines. When the unit is running, the larger line should be cool and sweating. Never frosted. If not, it is probably low on freon. Also, if you have a thermometer, check the air temperature at a return air register, then at a supply air register. It should be cooling the air at least 15 degrees. Anything less than that - call a repairman.
Since I have no clue what a return air register or a supply air register are, I asked, and she said:
|The return air register in my apartment.|
As you can plainly see, I tried the
paper test. It works.
You might be looking for something like this picture.
As for heaters: Change the filter and turn down the thermostat. Those are about the only easy Do-It-Yourself things. I highly recommend having any heater checked by an HVAC tech at the start of the season. We do more than "clean" it. We check safety controls, make sure it lights properly, and most importantly, check the heat exchanger for damage. No one wants Carbon Monoxide poisoning! Electric furnaces should be checked too!
There you have it! I don't have any particular question to ask today; just tell us what your weather is like! And where you are, I suppose, so it all makes sense.