I've been posting several tips on saving energy lately since many of us Southern California residents have seen very high utility bills. The recent hot weather means more A/C use which translates into high bills. One of our readers sent me some additional tips that I'll post over the next several days. (Thanks, SB!).
In order of most to least:
1) Install double pane windows/doors
2) Install new weather-stripping around doors/windows. This includes interior doors to furnaces and A/C units. If you have a furnace/ac in a closet by itself, then the door needs to be weather-stripped. This is because the furnace/ac draws air into it, and it will draw air that has already been heated or cooled, and will send this up the vent and out of the house. This work requires an assessment by an Energy Partner or HVAC contractor to make sure the appliance is operating correctly, and has sufficient combustion air. (Combustion air is drawn via vent(s) from attic, crawlspaces, outdoors).
3) Door jambs! If worn, replace. Especially the sill plate.
4) Look under your sinks! The place where water and drains enter/exit the walls is a significant source of drafts. For small holes, seal with caulking. Larger holes should be properly repaired with wire mesh or plates and caulked.
5) Electrical outlets: switches, outlets, cover plates for lamps and so forth. You can get little gaskets from home supply store that fit under the cover plates for all of these-very inexpensive.