Our power company has started sending monthly letters comparing our home’s energy consumption with that of our neighbors. As it turns out, we’re well above average, and I’m kind of interested in figuring out why.
One suspect: when we run our air conditioner during the warmer months, we typically set the blower to the always-on position. We do this when we come home from work (~5:30 PM), and it stays on until I get up the next morning (~6:30 AM). The blower switches to high speed whenever the air conditioner is actually running, but when the AC is off, the blower reverts to its lower speed.
Ballpark figure, how much power might this blower using in the lower-speed mode? I mean are we talking about 200 watts, or 2000 watts? This is for a 3 bedroom home, ~2000 square feet.
Hard to say without knowing some specifics of the fan, but fan law shows that decreasing the fan speed cuts the power by quite a bit (it’s a cubic relationship).
I’d guess the fan running at low speed isn’t the only cause of your power issue.
Don’t know, and no. House was built in 1995. Cathedral ceiling inside. Master bedroom is on first floor. Two upstairs bedrooms, upstairs bathroom and a loft space where wife and I have home office; those rooms have the only flat ceiling with an attic where we could conceivably blow in more insulation. Above the “main” room and kitchen, where the ceiling slope matches the roofline, the space between ceiling and roof is fairly narrow. I doubt we could get more insulation in there without interfering with attic ventilation.
This of course sucks for AC in the summer, and also the heating bill in the winter…
How warm do you keep your house in winter? About the only thing we really do differently than anyone else is keep our house fairly cool (around 18ºC/64ºF) in winter, and our bills seem to be much lower (when we sold our last house, we had to show people the bills because they didn’t believe they were that low). We use a programmable thermostat, too, so the house is the warmest when we’re home and awake.
We have the same kind of ceiling in our kitchen/dining room/living room, and we are looking into adding a layer on top of the existing roof. It’s entire purpose is to add a layer of additional insulation. Now my house was built 45 years ago, and I bet that the standard for insulating was much lower then.
As far as other energy uses. Have to looked at months that don’t require heating or cooling, spring and fall? That should give you an idea if your higher usage is insulation based, or other energy users (hot water, refrigerator, hot tub, etc.)
If you really like having the main blower running all the time, you can get T-stats that will randomly turn it on and off throughout the day to keep the air circulated. If I have mine set that way it aims to have it running about 30% of the day.
Don’t forget to change your furnace filter probably more like once a month rather then once every three months if your running your fan that often.
If you pull the furnace cover off, then pull the bottom cover off (there’s probably a single screw holding it on) you’ll have access to the motor. On the motor you’ll find a label that will tell you how many watts (or at least how many amps) it uses. Of course, it might just give you the max, but at least it’s something to work with. If you have a clamp meter, you could just connect that at your breaker box and see how many amps it draws in fan only mode.