Wednesday, July 18, 2007

Saving Money on Cooling

A friend of mine recently told me that they estimated that out of their last power bill half of it was due to using their air conditioner in the summer. He noticed my house was fairly cool, but I didn't have mine on.

I have to confess. I have central air in my house, but I almost never turn it on since I know it is such an energy hog. This summer for example, I don't think I have used it yet. I typically only turn it on with the house temperature gets above 27C (80F) and then I only use it to cool down the house so I can sleep at night.

So how do you live without air conditioning? Fairly easily, but there are a few steps.

Step 1 - Plug leaks - Most people wait until fall to install weather stripping and prevent air leakage in your house. I have never understood that. I did as soon as I move in because it keep the heat in the house during winter and also keeps the cool in during the summer. Plug every little leak you can and watch your power bill drop in the summer.

Step 2 - Overnight Cooling - If you overnight low gets down to under 21C (70F) make sure you open all the windows you can in your house. If you have a basement door open that as well before you go to bed. This will create a natural draft in the house which will dump out the hot air from your top floor and bring up the cool air from your basement. I can typically get my house down to the overnight low if I open up my windows an hour before sunset and close them first thing when I wake up the next morning.

Step 3 - Manage Daytime Heating - Close all your drapes/blinds that get sunlight on them. For example I close off the north side of my house first thing in the morning since that when I get sun there. In the afternoon the south side of the house gets baked so I close those off too. Try to avoid drying laundry, using the oven and stove top to produce extra heat during the daytime. Summer is about BBQ season for a reason, you want to keep the house cool. Also try to use the microwave more if it saves turning on your stove top.

Also if you haven't switched to Compact Florescent Light bulbs I suggest doing it now. As regular bulbs are the worst in hot weather. You pay extra power to run a regular bulb which generates extra heat in your house (since 80% of the energy is converted to heat) and then you pay more money to use your air conditioning to cool off the house to get rid of the extra heat.

Step 4 - Cheap Man's Air - My last trick I use before turning on the air is just a modification of step 2. Except I use it during the day. I open up my basement door and turn on a fan at the base of the basement steps to blow cool air up. Then I go upstairs to the top floor and turn on both bathroom fans to suck out the hottest air in the house. The again creates a draft to cool the house, but this time I'm helping it along with a fan in the basement. The trick here is to avoid opening a window which could move the hotter outside air into your house (since heat tends to move from a hot area to a cool area). Powering fans is MUCH cheaper than running an air conditioner compressor. I recall reading on a website that you can run a ceiling fan for an entire month for about $3 to 5 dollars.

So best of luck to everyone as you keep cool this summer.


Frog of Finance said...

If you have a central air system, one thing you can do is simply run the fan, without turning the cooling on. This will mix the cool air from the basement with the warmer air from upstairs.

I do this a lot, and unless it is really hot and sunny outside, it almost feels like the air conditioning is on, without the power drain. It also reduces the temperature difference between downstairs and upstairs.

J at IHB and HFF said...

Hello. Your list is a good start that most people can do, although #4 will not exhaust much if the house is sealed everywhere else, or might intake hot replacement air if you do break the seal. You can use an attic fan or evaporative cooler or other cooling ideas from my Inexpensive Home Building blog.

Mr. Cheap said...

Great post with some sure ideas! If you don't have central air, an alternative is to just cool your bedroom (if you need the AC to sleep), a smaller space obviously uses less power to cool. When I was a kid we used to sleep *IN* the basement on the hotest nights (our below ground basement was always nice and cool). Apparently it takes more power to lower the temperature of humid air then dry air (since water vapour has a higher heat capacity), so running a dehumidifier (which is cheaper then an AC) along with the AC can save power (you don't feel the heat as much with dry air either has been my experience)

Mr. Cheap said...

sure should be super in the above post :-)

Canadian Dream said...


Acutally that might not work. It depends on your heating system. For example mind doesn't have any air intakes in the basement, so all it does is move the air around on the top to floors. Yet if you do have air intakes in the basement that would be an easy fix to cool the house.


True it won't exhaust much if you have a perfect seal house, but I haven't seen one yet that doesn't leak a bit. Good point on I could be bringing in some warmer air from outside. Yet I find my upstairs is often very warm so I take the risk to vent some of that heat to at least cool down the upstairs.

Mr. Cheap,

Great idea on only cooling the rooms you need. Your correct that humidity if a huge factor in cooling with AC. Since the AC often has to remove most of the moisture in the air first to allow a temperature drop. I never thought about running a dehumifier, but then again in Regina we don't get the humid to start with.

CD said...

Speaking of compact fluorescent bulbs, have you found a good brand name? I've tried several, and they all provide a dim light solution. On top of that, most have a slight delay when turning on, which can be aggravating.

telly said...

Great ideas and great post!
We've recently installed a couple fans in the bedrooms upstairs. We also use a fan on the floor in the hallway. For us, the biggest difference is made by closing the shades. Our house stays much, much cooler by doing this and isn't a problem because neither of us is home during the day (when the AC is off). But I have to admit, we've been using our AC A LOT this summer though I think Windsor, ON has to be one of the most humid & hottest cities in Canada. :( Most nights we haven't been able to fall asleep if we try to keep the windows open at night.

Thankfully we had an energy audit when we moved in and have made a lot of changes to make sure we're wasting too much since our house is over 80 years old. We added insulation to the hollow walls and put in a ne furnace & AC unit so it's rather efficient (I'm justifying our love for AC aren't I?!) ;)

Canadian Dream said...


All CFL's tend to have a slight delay when you turn them on. The ones now are hugely better than the old ones. I'm so used to it now that I don't even notice, but I've been using them for about five years now.

As to the dim light issue. I don't think it is a brand name issue, but rather just a fact that the light is more white than a normal lightbulb which has a slight golden colour to it. The result it your room looks a bit dimmer than your used to even if the bulb is putting out the same amount of light. To solve it I suggest just using more lamps. I've got four in my family room with use a total of five bulbs at 13W each, so at 65W I have a ton of light for the same power of just over one normal light bulb.

I hope that helps.


Humid heat is way more uncomfortable than dry, so I don't blame you using your AC. Good to hear you are dealing with the air leaks in the house. In really old homes they can be horrible.

Thanks for all the feedback everyone.


Lazy Man and Money said...

I hope that no one steals anything while you are asleep with the basement door open. That's some good neighborhood. It only takes one theft before all your gains are gone.

Gregory said...

I recommend adding a cold air return to your basement to help move the air. I have cold air returns in my basement and run the furnance fan continously (low speed). This is still noticiable on the electric bill, however should be cheaper for those with newer furnances (DC, variable speed motors etc). I also recommend awnings on south/west exposures as they don't have to block the view much while they keep the sun out versus closing blinds on the inside when the heat is already in (or good positioning of trees).

Gregory said...

Oh forgot one more suggestion, check/change your roof vents. Make sure you have enough ventilation. Look into the Maximum Ventilation (no I have no relationship with the company) roof vents, I have noticed I can keep my house cooler since I switched to them (even though I'm above code with my attic insulation).

Canadian Dream said...

Lazy Man,

Actually I mean the basement door in the house, not outside. Sorry for the confusion.


Good points. I forgot to mention trees. I've been looking at getting one to block some of the light in my south facing living room window during the summer. Thanks!


byno said...

Two more tips that have really helped us.

1. Phantom screens. We have these on all of our doors and it allows us to create a good draft throughout the house without letting the bugs in.

2. Awning. We installed an awning over our south facing windows and it has helped keep the sun off the windows during the day.

We have no A/C yet our friends are always commenting on how cool our house is. If you use all of the tips from this post it really is possible to keep a house cool without A/C.