Use a Programmable Thermostat to Save Energy
Are you using a programmable thermostat in your house? If you aren't, chances are that you are losing a lot of money. Since I've started using one, I've saved up to 30% of my electric bill during summer and winter months just by using a $50 programmable thermostat.
Here's why it works. When you are gone during the day, there's really no need to have your air conditioning or furnace running at full power. But it's frustrating to come home to a really hot or really cold home after a long day of work. If you don't have a programmable thermostat, that's your only option.
You also don't need to have your heat turned up as high when you are asleep as you do when you are awake. However, there is nothing worse than waking up nice and warm and then getting out of bed to a freezing house. If you want to take your morning shower in a warm bathroom, you've got to get up early just to turn your heat back up. It's a hassle...and when things are a hassle, we tend not to do them.
If you install a programmable thermostat (which you can do on your own, by the way), you can set your thermostat to turn down the heat or off the air conditioning as you leave for the day, and you can set them to turn back to your desired temperature just before you get home.
The same concept works at night - you can turn your heat down at night and set it to turn back up just before you wake up in the morning.
The only thing you have left to do is to choose which programmable thermostat that you'll use. I've used a Vox in the past, and now use the Honeywell programmable thermostat and love it. The major benefit is that it allows you to create different settings for different days. That means that you can set your thermostat to perform one way on Monday - Friday, and a different way on the weekend days. Because, really, there is nothing worse than forgetting to change your thermostat and waking up late on a Saturday morning to a freezing cold house!
If you aren't yet using a programmable thermostat to save energy, it's time to start. Not only will you save energy and money, you'll be more comfortable is your home!
I turn my heat down to 52 when I leave for work...and there's no way I'm coming home to a house that's 52 degrees in the middle of winter. :) I suppose turning the heat down manually works, assuming you remember to do it every day (with 3 kids to get out the door, I typically didn't). I also turned my heat down much farther while I was gone than when I was sleeping at night so I would have had to remember to turn it down twice each day. It's probably not as important with air conditioning - I can manage to wait for a house to cool down, but I hate to be cold!
If you typically leave your heat (or A/C) turned up overnight and during the day, then yes this will help. HOWEVER, most people turn their heat down when they leave for the day and at night when they go to bed. The downside is that you come home (or wake up) to a cold house. If you install a programmable thermostat you'll actually use MORE energy. This is because, instead of waiting to turn up the heat when you walk in the door, the heat will kick on before you arrive. Similarly, in the morning, instead of just leaving the heat down, it'll kick in before you wake up so that it's toasty when you get out of bed. If you want to get up (or get home) to a warm house, then go ahead and install a programmable thermostat. If you want to save energy, don't bother. My plumber told me this when I asked about installing one and he convinced me that it wouldn't save me a dime.