November 22, 2006

Windows, heating and insulation

We need a new heating system! There is an oil heating of about 1988 in the house at the moment and our first bigger investment will be to modernize the heating system. We definitely won't go on heating with fossil fuels - too expensive and, more important, not ecological at all. Moreover, personally I don't feel safe with all that oil in the cellar of a - partly - wooden house...

At first we wanted to go for a pellet heating system because it is based on renewable resources. Well, and I simply liked the thought of heating with wood, sounds somewhat "natural" (I admit, I'm an "eco-kid" of the eighties, socialised with Greenpeace and WWF, whale-saving and demonstrating against nuclear power stations...).
But we realized pretty soon that this solution is far too expensive for us. The investment costs are really high and the wood pellets themselves become more and more expensive, too. Therefore we decided to go for gas (central, not in tanks). Later on we might combine it with solar cells, but this is a bit difficult, as the cells mustn't be visible from the street (listed building).

Next point to it: INSULATION... Take a look at our windows (again, not a good picture, sorry...)!

You could just aswell try to heat the street outside, the wind whistles through the chinks and gaps just about any song you like... Now, of course we want to keep these old windows and frames, anyway we're not allowed (and never would!!!) to put in new windows of another kind (again: listed building).

Our windows - this just as an interesting and uttterly off-topic detail - must open towards the street instead of towards the room (in modern houses). This makes window-cleaning quite an adventure :-)

But back to topic: we thought of adding "inner windows" in order to improve the insulation. But they mustn't be too sealed either, this would influence the climate in the house which we want to avoid. And we're talking of 22 (!!) windows, each one with a very individual size - that would mean 22 one-off productions... We also thought of insulating the inner walls - but my father-in-law, an engineer, convinced us that it would be a nonsense from the point of view of construction physics.
Any other ideas?


Angus said...

I had wondered if insulation would be one of the first things on your list. I'm so glad that you won't be insulating the outside of the house. Down south here I see more and more nice looking house (timberframe / stone) disappearing under styrofoam sheets and then stucco.
I've always wondered though how one can insulate older house here in Germany because the walls are solid, as opposed to many houses in N. America which have space in the walls which can be blown full with insulation.
Insulating the inside of course makes the rooms smaller and covers any nice details there.
Hmmmm, was zu tun? Is it possible tho remove some (half) of the thickness of the wall between the timbers and put insulation there? Probably not feasible? And too much work.
I'm looking forward to your decision.
And love the windows!

Felicia said...

Do they sell the plastic film insulation? Mostly made by 3M, I believe. I am using it on windows in my colder rooms. I've used it again and again over the years and while not a permanent solution, it works well for the winter, is pretty invisible (you use a hair dryer to shrink it to fit around the window) and then you can pull it down in the spring when the weather's nice and you want to open the house again.
I'm sure you could buy some on the internet if you can't find it there.

Greg said...

I will preface all this by stating that I have never lived in snow country, so take it for what it's worth.

I would concentrate on the attic space. Imagine your house as one big chimney. As the cold air comes in from the bottom (doors, windows, etc) the hot air then goes up and out the roof. Insulate the attic space and stop air infiltration at the bottom.

Stopping air infiltration can be done with shirk wraps (plastic wrap on the windows that is sealed with a hair blower). You can also use things like spring bronze (Google it), and sash locks (may not work on your windows). Doors can be better sealed with weather stripping, and then there is the old friend caulk. Fifty dollars worth of caulk will make a work of difference. There is also a kind of “temporary caulk” that can be used to seal cracks in windows and then is easily removed when winter is done.

Ragnar Bartuska said...

Well, regarding wall insulation always remember a solid brick/stone wall already provides much better insulation than 2 or 3 layers of wood and a layer of plaster/drywall. Especially in a timber frame they often used mud/clay with lots of straw for the infill, and straw is pretty good insulation.
Further insulating such a house is usually (at least by preservationists) seen as unfeasible because it is very likely to trap moisture and ruin the house. And my grandmother is the owner of a 1900(?) brick farm house, I know what I'm talking about... before we installed gutters on the rear side our kitchen cabinets rotted out from the back...

The windows are a different story. I guess the only more or less historically correct way to do this would be putting in inner windows as you mentioned.
And that's one big difference between Austria (where I live) and some areas in Germany: in Austria it has been unthinkable for several centuries to put in single pane windows! There are always two windows in one frame with about 15cm (6") of air space between them. The older ones have outwards opening outer windows, just like yours. Seems like they went out of favor around 1900 but survived much longer on the rear side of houses, facing the yard. That's the reason why most houses in Vienna still have their original windows facing the street, but not facing the yard...

Long story short, if you're really concerned about heat loss you could construct some temporary inner windows made of wood and plexiglass. If you take thin plexiglass it shouldn't be too expensive (thicker plexiglass is horrendously expensive, for a school project we needed 30mm plexi which was something like 600 Euros per square meter, fortunately we only needed a 15x15cm piece).

Greetings from Vienna

Anna said...

Hello everybody! First of all: thanks a lot for all your comments and advice - much appreciated!!

@angus: I absolutely agree with you - no idea, why people "verhunzen" (sorry, I don't know what that would be in English) their old houses/facades with that modern insulation stuff...
I've never thought of your idea, though - I'll definitely discuss it with my father-in-law next time!

@felicia and Greg: You're right about the plastic wrap, my sister used to make that when she lived in a house heated by a single tiled stove. I must admit that I kind of repressed that possibility - I have spent a winter in Siberia in the late nineties and they used to seal their windows that way. With the result that you had a real indoor sauna... But I will try it!

@Greg: That's exactly what my father-in-law said (insulate the attic), so I guess he (and you, of course!) was right... Thanks!

@ragnar bartuska: Hallo nach Wien! When I moved to Germany I was quite surprised about the missing "inner windows" in old houses. I'm originally from Switzerland and I knew exactly the system you described from Austria. My grandmother used to fit the inner windows during winter and hung them out in summer.

Good point about the moisture!That's what I meant with "construction physics" and that's also why I'm always on about the "climate" in the house. I'm really afraid of changing it - especially because we don't have any problems with moisture so far. Maybe I should just go for warm knitted jumpers :)

Thanks again, Anna

Greg said...

"verhunzen" - In English I think that would be "remuddle". It's a play on the term "remodel". It’s when you remodel a house, but do it badly. I had forgotten all about the double windows. Back in the 1980s I stayed in a horrible Soviet era, cement apartment building in St. Petersburg, Russia for a few months. I think it was built in the 1960s. All of the windows were double windows just as Ragnar Bartuska described, and the front door was double as well. You first opened a steel outer door, and then opened a wood door with thick padding on it. It was very interesting.

Ragnar Bartuska said...

One thing you might try to stop the wind from blowing through the windows is the rubber stick on insulation strips made by Tesa (not the foam (Schaumgummi) kind but the brown rubber stuff).
Here in Vienna I used silicone caulk, but I'd be less thrilled to try that in a house several hundred years older than the one I have here. Especially since I'm on the second floor I certainly don't have any moisture problems to expect...
On the other hand, silicone is dirt cheap (I used roughly one €1,39 cartridge per double window with upper lights) and should be removeable if you apply it over the paint. If you are interested I can give you a step-by-step guide. I'm sceptical due to the age and construction type of your house though.

At my grandmother's place we take out the outer windows in summer. The original outer kitchen windows don't even have hinges, they're designed to be put in in autumn and removed in spring.
On the ones that have hinges we keep the outer windows open during summer.

Anna said...

Sorry for not answering to your comments earlier...

@Greg: Wow, so you spent a few months in the Soviet Union! I missed that, my first journey to Russia was in 1992... But I also spent six months in St. Petersburg, working in a human rights organisation. And of course I also lived in one of those horrible buildings made with precast concrete slabs in one of the suburbs - driving to the centre by "marshrutka" every day.
May I ask why you were in Russia - for work or studies?
Oh, and thanks for the term "remuddle", blogging in English definitely improves my language skills :)

@ragnar bartuska: Of course you are absolutely right about taking out the outer windows. Same thing at my Grandma's place - I mixed it up... Seems quite logic as they are called "Vorfenster" in Switzerland (probably the same with you!?).
If we should decide to go for the silicone solution, I'd be grateful for a step-by-step guide! May I take you up on your offer should the situation arise?