Wednesday, November 21, 2007

Electricity Challenge - Keeping Cool

Well, as expected, the recent heat wave has seen our electricity usage jump up somewhat to an average of 22.6kWh's per day this past week. That's almost as high as our highest week a while back when we were using heaters in both kids bedrooms. So, I'm a little bit disappointed about that.

BUT, as they say "what goes up, must come down". LOL. So we've got some work to do on that. I would be extremely happy if I could manage to keep it down to around 20kWh's per day over the hotter months.

In contrast, our hot water usage is now back down to zero thanks to the long days of sun we've been getting (solar hot water). I can't ask for any more than 100% from it can I? :-)

So, how are we going to go about reducing our electricity usage over summer? We have a few plans. Some of them require capital investment so will take some time to achieve.

Recently done:

  • I finally got around to cleaner the filter on the reverse cycle air conditioner on Monday. It was FILTHY. We noticed a difference in the cool air coming out of it almost immediately. I *should* have gotten to it months ago. Never mind, it's done now.
  • We're noticing an improvement in how hot our floor gets now that DH has installed the base infill around the bottom of the house. Before that, hot air blew under the house and heated it through the floor. This will be our first summer since it was installed so I'm hoping it will make a difference.
  • Installed window coverings in office ($40 silver venetians from Spotlight) - I'm really happy with the way they look and they're definitely helping with the temperatures in that room.

Short Term Plans:

  • Purchase another blind from Spotlight for front lounge window to give a second line of defense from the hot afternoon sun (has curtains but they're not brilliant at keeping the sun out)
  • Add a door sealer to laundry door to help keep draughts out of main living area (have ordered - should arrive soon I hope).
  • Work on keeping air conditioner at 25C (77F). DH currently has it set for 23C (73F) so we'll see how we go. He feels the heat more than I tend to.
  • Turn dishwasher off before it goes through the air dry cycle. This is adding heat to the kitchen. Will also save on electricity being used for that cycle. I can't figure out how to do that other than manually so this will only work on days when it's run during the day and not while we're in bed.
  • Use crockpot (and solar oven when we get one made) for cooking to avoid heating up kitchen/living area.
  • Make use of fans as much as possible. Currently have a ceiling fan in lounge and our room plus 1 pedestal fan.

Medium Term Plans:

  • Install a ceiling fan in family room where we watch TV so that we're not as tempted to turn the air con on unecessarily.
  • Replace curtains in lounge with ones that are better block out and cover the window better (what we have are seconds curtains and they're not really the right size). Our lounge room is on the North West side of the house so bears the brunt of the summer sun.

Longer Term Plans:

  • Build pergola with laserlight to block some of the summer sun.
  • Install blinds to front verandah to keep the afternoon sun off of the house.
  • Install solar panels for electricity usage (or at least partial electricity usage).

I just did some research and an air conditioner of our size (around 2HP - think ours might even be 2.5HP) uses on average about 2kWh's of electricity per hour of usage. My goal to keep our electricity usage under 20kWh's per day average would only allow us around 2 hours of air conditioner usage per day. Which means I'm not sure if it's a realistic goal. Of course, it's rare that the air conditioner would be operating flat out so that may allow us a little longer. I guess I'll do some playing around and see how we go.

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