Thursday, January 31, 2008

Shirtsleeve Weather

We're just coming off a few days of the kind of cold that makes me think about survival. It was a bit unusual because there was wind as well as cold, with wind chill values around -40 to -50ºC. Today I was out running errands around noon, and it was only about -20º, and by late afternoon it was maybe -10.

Working in the sunroom this afternoon, Dad and I took off our jackets because it got too warm. There is some heat that leaks into that space from the rest of the house, but we keep the doors closed, and the one heating duct that feeds into it is closed off. Mostly the space is heated by the sun through the windows. Even during the extreme cold over the past few days, the sunroom has been cooling to only a couple of degrees below freezing over night, and warming nicely during the days. Today the heat flow was reversed: Garth opened up the doors into the rest of the house and turned the furnace off for a couple of hours.

The thermal performance of the new space has been improving bit by bit as we insulated the outside walls, closed in the gaps where warm air could rise right into the attic and away (big improvement there!), and finally started sealing all the walls up with vapour barrier. Today we were applying the last big sheets of poly and finishing the seams around windows. As we got down to the last little details, I noticed the sound of a big truck, engine braking somewhere nearby, and realized that the sound was much fainter than usual. With that thought, I also realized that the room had been feeling different over the last few hours. If someone had asked me, I might have said that I sensed it becoming more airtight, but in reality, what I sensed was probably just the gradual reduction in sound.

We are very pleased with the sunroom so far. Over the next couple of years, I hope to add a rock wall or perhaps water containers as thermal mass, to smooth out the heating and cooling cycle a bit. Insulated blinds or shutters are a big priority, too. If we can slow the heat loss overnight, I am hoping the room may become a significant heat source for the rest of the house.

And if you're wondering what it will be like in July, check out my post from 2006 about designing window overhangs. From what I saw of the rafter shadows on the window framing last summer, it looks like this is going to work, folks!


MojoMan said...

Check Paul's blog, "Wondering!" at for posts about his solar greenhouse addition. He's using big barrels of water as thermal mass.

arcolaura said...

Yep, I've been watching Paul's progress with great interest. I'm especially intrigued by the discovery that his area is not so very much warmer than ours, even though he's in Arizona. Unfortunately our addition was already well underway when I read Paul's description of a "solar closet" - otherwise I would have made our addition a bit bigger to accommodate one. But if I waited to have a perfect design, I'd never build. And overall, I'm quite happy with the way this project is turning out.

Madcap said...

It's a great project, and I love that you're making an older house more sound rather than starting from scratch. I was talking to a friend recently who was telling me that the cost of retrofitting an older home for geothermal is about twice that of a new furnace - which really isn't that bad, considering. It's something we're going to look at after everything else has been dealt with. And hey! You and I are both still married - even after all the renos! Cast iron vows, ya figger? ;-)

arcolaura said...

I think the metal of these vows is being fire-hardened! Actually, now that the sun is streaming in and visitors are admiring the view and the feel of the space (ragged though it still is), Garth keeps saying how proud he is of me. And whether it's my accomplishment so far, or his recent experience living in a back brace and being rather dependent for a couple of months, I don't know, but he seems much more willing to listen and give my ideas a chance. Either way, we have this project to thank! The other day we were doing some vapour barrier seals up high, right in the same area from which Garth fell back in August. There was some discussion about which of us should balance on the plank up there. Garth said his reach was longer than mine (true) and he was probably more comfortable than I with it. I was glad to hear that, and nervous but glad to watch him work up there, like getting back up on a horse after falling off.

Great to hear from you, Mum! Can I assume from what you said that your renos are going well? Are you in yet?

Madcap said...

My renos aren't going at all, at this point. We need to sell our present house to fund the last lap, and nothing's moving real-estate-wise. Spring's a-cumin. I anticipate everything will be hopping again then. And then we'll have to live somewhere while we finish the next place. Bleh. I try not to think about it!

arcolaura said...

A tent? ;) Rather than living in another place, we've been living in less of our place, but this week Dad started cutting holes in the ceiling of the remaining bit of living room, and nerves are getting a bit frayed. There was a house for sale nearby, that might have worked as an interim place, but they wanted way too much for it, and then it sold.

Well, I hope spring gets things moving for you in a good way.