Wow! The electric bill just arrived. Salt River Project has started including a bar graph to compare 2008’s month-by-month kilowatt-hour usage with 2007’s. Though it’s a little hard to read, I’d say that this month I’ve dropped my power consumption by about 275 kWh off the same period last year, from about 875 to about 600 kWh. The bill is only $63.52, probably an all-time low. It also looks like I consumed about 150 kWh less than I did last month.
How? Here are the strategies I’ve been using:
1. Replace most incandescent bulbs with CFLs.
2. Cut the pool pump’s run time to four hours a day.
3. Jack up the thermostat in the summertime and jack it down in the winter.
4. Leave the air-conditioning or heat off if temperatures are even remotely tolerable.
5. This month, use a space heater instead of the central heating.
Last month, I did use the HVAC to heat the house on a half-dozen or so mornings when the house was chilly; as a result, usage dropped only a few kWh compared to the same month in 2007. But at the beginning of the current billing cycle, I bought a space heater and have used it to take the chill off only in the rooms where I hang out (not the bedroom). I’ve been using it just in the mornings in the kitchen, dining room, and bathroom. Even though this month has been a lot cooler, the bill was $13 less than last month’s! It’s about $10 less than the 2007 bill—not bad, considering that SRP raised its rates by 6 percent this year.
This confirms my suspicions that, protestations of the air-conditioning service guys notwithstanding, it’s insane to heat and cool eight rooms when I occupy three rooms. I’m going to move forward with my scheme to install a room air conditioner in the bedroom. The programmable thermostat is already in place (hasn’t been used yet this winter, because I’ve left the system off). Now all I have to do is buy a unit and find someone who can cut a hole in the wall, install it, and caulk around it correctly. The bedroom has no window—only a sliding door—and so the contraption will have to go in a block wall. But since Satan, the previous owner, put one in the garage, I don’t see why I can’t get one in the bedroom.
Air-conditioning contractors will tell you things, by way of discouraging you from dorking with the system, that appear to be…well, shall we say, mythological.
For example, you hear all the time that you should not leave the air-conditioning off until the day starts to get uncomfortably warm, because this will cause your house to get “heat-soaked” and make your unit work harder to cool the place back into the comfort zone. Last time my AC guy was here for the twice-yearly routine inspection, he insisted this would cause the unit to run three to five hours, nonstop.
That is just flat not true.
I’ve been in the habit of leaving the AC off until the temperatures outside reach around 98 or 100 degrees and inside are in the high 80s. The unit most certainly does not run for hours to cool the place down to 82.
And IMHO, there’s no such thing as “not heat-soaked.” Block walls work very much like trombé walls: they gain heat during the day as the sun beats on them and ambient heat rises. They radiate heat late in the day and through the evening after the sun goes down. It does not matter whether you cool the air inside the structure, nor does it matter much whether the block has holes inside it; if your walls are made of slump block, your walls will heat up during the day and start radiating into the house about 4:00 or 5:00 p.m. Concrete block has much the
same effect as adobe. If you live someplace where the evenings chill off after hot days, such as New Mexico, this is a grand thing. If you live in Arizona, where a balmy summer evening is around 95, it’s a less than perfectly ideal phenomenon.
That notwithstanding, I still wouldn’t have styrofoam, chickenwire, and mud walls. pbfttttt!
Next summer, I’m going to set the thermostat to effectively go off around 9:30 or 10:00 at night and then come back on at 82 degrees a half-hour before sunrise. Then I’m going to use the room air-conditioner to cool the bedroom to the 76 or 78 degrees I find comfortable for sleeping.
Why chill 1860 square feet at night, when I’m only occupying about 35 square feet?
Why not put a window unit into a room that HAS a window and make that your bedroom? You could have a summer and a winter bedroom!
🙂 That WOULD make sense. Actually, I’ve thought of tricking out the TV room (i.e., one of the smaller bedrooms) as a second nighttime roost. Because the regular master bedroom is between it and the rising sun and the kitchen, dining room and family room are between it and the setting sun, that room stays a lot cooler in the summertime.
Still, it’s difficult to install a window unit in the sliding windows these houses have: they’re not sash windows; they’re like miniature Arcadia doors. So you have to fill the space above the top of the AC unit with a piece of plywood (a lovely decorator item) and then figure out how to jam the slider so the burglar can’t open it the rest of the way and climb in. Or…simply kick out the plywood and climb over the AC unit.
You might not even have to cut a hole in the wall. The newer AC units I’ve seen seem to be more amenable to use with sliding doors and windows.
Sorry about the hideous link but QVC is where I first saw them demonstrated:
http://www.qvc.com/qic/qvcapp.aspx/view.2/app.detail/params.item.V26931.desc.Amcor-14000-BTU-Portable-Air-Conditioner-with-Remote-Control
I’ve considered one for even my little 1 bedroom apartment because the AC is in the living room and doesn’t really cool the bedroom to a satisfying degree. But it would have a several year payback and I’m not 100% sure how long I’ll be in my current digs.