Air Conditioning Filters (Cheap, Minutes)

This may be an obvious way to conserve energy and save money, but...
Don't forget to change the filters!!! A/C units with dirty filters can use 5-10% more energy!

I use the 3M Allergy filters, which are recommended to be changed every 3 months. Some filters require washing, so they should probably be washed monthly. Regular fiberglass filters should be changed monthly.

I keep a sticky note on the thermostat with the installed date of the filter on it so I'll see it every so often. This helps me remember to change it as close to that 3 month mark as possible. I also write the date on the filter itself, just in case. While you're changing it, go ahead and vacuum the dust from around the grate - both inside and out. It'll help the filter stay cleaner slightly longer.

One way to save a little more money is to stock up on the filters if you see them on sale. That will keep several on hand for when you need them, too.