Use sunlight from your windows to conserve heat in your home

[Bobbie Soxer]

A good way to reduce the amount of energy used in your home is to invest in some energy efficient window treatments.

I live in Canada where the winters can get down to about -30 degrees Celsius, so heating costs are always an issue. Last year I tried a trick that saved me a significant amount.

For the windows and doors I wouldn't be using often in winter, I filled the cracks with insulating tape. Then I purchased some window shades with Energy Shield (http://www.levolor.ca/products/cellular-shades/energy-savings.php), which uses the sun's natural light to preserve the heating in your home. The ones I got were from Levolor, but I'm pretty sure other companies make window coverings with this feature as well.


Hope that helps!


What are some of the ways you reduce heating costs in your home?

[Rob Beckers]

Hi Bobby,

Welcome to the forum!
I think you hit the nail on the head: Covering the windows at night can net very large energy savings. Most of the older dual-pane windows are less than R2 in insulation value. They leak heat to the outside like there's no tomorrow. The cellular shades you linked to should work pretty well, the air pockets that it's made off form an insulating layer. You should see the savings reflected in your heating cost.

I've seen people make their own heavy-duty window coverings for off-grid and passive-solar houses. Usually layers of thick fabric with a layer of reflective material (probably much like that Energy Shield stuff you mention) in between.

-RoB-

[Bobbie Soxer]

Thanks for the warm welcome, Rob.

I agree, I live in an older building so I was shocked when I found out just how much heating was lost through my windows and doors alone! Although I was skeptical at first, I'm glad to say that the shades and insulation helped a lot.

That sounds interesting that there's DIY window coverings. What kind of fabric and reflective material do they use? Does it have to be a specific type in order to be effective?

[Joe Blake]

I used heavy duty clear vinyl taped (good ol' duct tape) to the wall surrounding the window to give myself a kind of double glazing. This seems to be good for summer (preventing ingress of some heat), winter (minimising heat loss while still allowing light in) and even a small reduction in sound transference. It cost me about $40 Australian and so far is into its second summer.

My large window has venetian blinds installed, with a wand to control opening and closing, so I just cut a small hole in the vinyl (leaving the flap attached), passed the wand through, and voila, I can open and close the blinds, with no effect on the heat transfer.

Admittedly it doesn't look particularly "flash", but what the heck, I live on my own and it's just a painted brick wall.


Joe

[Rob Beckers]

One more comment about old windows and heat loss: I had an energy audit done on my (then) 20-year old house. Not that old of a house you'd think. Yet, the blower door test found that most of the readily identifiable air leaks of the house were around our windows. Turns out that 20 years ago it was common practice to fill the space between the window frame and the rough opening (framing) with a little fiberglass stuffed in there. Result: Those 30-some windows added up to gail-force winds through the house! :weird:

Those windows were on their last legs anyway (alu-clad wood windows, you'd think they should last longer than 20 years), so we replaced them. Given the price of decent windows that is a very, very expensive thing to do, and not something I want to repeat in my life time.

If your windows are still good you can pull the trim off the inside, pry out the fiberglass stuffing, and use low-expanding polyurethane foam to fill those voids. Makes a BIG difference!

-RoB-

[Tom kent]

that is such a great idea. Most houses in the UK are so drafty (at least mine is) and during our damp and cold winters heating is a fortune! so using the sun light coming through windows is just ingenious! thanks.

[Joe Blake]

Since my last posting in this particular thread, I've had proper double glazed windows installed on the two largest windows, living room and main bedroom, both of which face due east onto a road.

The difference has been amazing. It's now moving into summer and in the winter just past I've had absolutely no need for any artificial heating. But the reduction in external sound coming in has alone almost made the whole thing worthwhile.

Another source of heat loss I hadn't reckoned on is the hollow cored external doors. There's not much mass in them, mostly air (which in itself is a good heat insulator, and there are not draughts inside the door) but sound comes through easily, so I bought some of the high density foam roll up camping mats, cut them into appropriate shape and glued them onto the internal side of the door. It reduced sound transmission as well as added thermal insulation. They don't look so good, but if I get sick of it I'll just slap on a coat of paint or maybe some sort of illustration.

I'm still considering whether to add a small skirt at the bottom to act as a draught excluder. But this might catch on the carpet when the door opens and closes.

Joe

[Jerry Smith]

I started using renewable energy, you may invest big but the result will make you live comfortable for a long time, You may also get paid..

[Joe Blake]

Interesting to see this thread raise its head again. So I can give another update.

Since my last posting there has been a fairly intense change in the climate over a fairly short period. Since January 1 to Feb 15 there have been roughly five-six days when the maximum daily temperature has been at or below the mean as published by our local weather bureau, in some cases it has exceeded this mean by about 10 degrees!!! In other words, it's not only getting hotter, it's staying hotter longer.

In real terms I'm now using my air conditioning for up to 12 hours per day to try and keep the internal house temperature at 26 degrees C or less. I've had periods of 5-6 days in a row with this happening. I've luckily got sufficient PV generating capacity to carry the load (1150 watts) and still have excess power but the A/C unit is not able to keep up with the heat, and I have to continue running it at night time. Not much point getting more solar panels. :huh: Just a bigger air con I suppose.

Anyway, I've decided to splash out and finish double glazing the rest of the house. Had the measuring man come round last week and size up the last two doors and windows. So except for the laundry/bathroom, which, whilst on the north side of the house, and cops a tremendous blast of sun during the day, is thermally isolated by an internal brick wall, the entire house is (or soon will be) double glazed. The big difference will be that one of the doors will have a sort of "pet flap" which will enable me to vent the hot air from the wheel-around air-con to the outside patio.

I'll see if I can post a couple of piccies when it's done. It'll be expensive, but worth it I hope.

Joe

PS To make matters worse, there has been virtually no rain around my place since December last year, and although I've installed a further 1,600 litres of rainwater storage tank to add to my existing 2,200 litres, without rain it's pretty much a wasted effort.

But on the upside on a "good" day the air con condenses up to 15 litres of water per day which I can add to the rainwater tank. ("Good" in this case means it's humid and I'm running the air con for hours :wondering:)

[Rob Beckers]

Joe, you truly live in an extreme climate over there!
Going from single to double-pane should make quite the difference. These days double-pane with a low-e coating in between works very well in keeping the heat out (or in, depending on where you live).

I went from double-pane to triple over here a few years ago. These were old double-pane windows, no low-e coating, and the frames were rotting out (alu-clad wood). The triples have two low-e coatings. It is very noticeably warmer inside, the windows no longer radiate 'cold' as they used to. Here it's the cold we battle of course, with good chunks of time below -20C, sometimes well below.

Good luck with the windows!

-RoB-