Should you heat your attic?

Kjmass1

2/3 of my attic is a finished playroom. All rafters have been spray foamed so it is pretty closed up. There is maybe a 5 degree difference between the attic and the rest of the house. It has a radiator up there. Is there any efficiency gains by having that radiator on? I keep it off as we don't use the space. I'm just curious from a heat loss perspective and if by keep that area warmer, heat from the rest of the house won't want to escape?

billtwocase

I would say heat the attic, if it is not a separate zone. I don't know if the piping is on an outside wall for the radiator, but you may take a chance on freezing with lack of circulation. As I said, if it is tied in to a zone below, it would only benefit letting it heat the space

Kjmass1

Sorry I forgot to mention- 1 pipe steam system.

You bring up good point. The pipe runs up an outside wall which has blown in insulation. I believe it actually runs 2-3 feet outside (ceiling of uninsulated, open air porch) which then goes up thru a dormer. In that case I probably don't want any water in that pipe?

How easy is it for a pipe to freeze? Steam and condensate would be passing through it every 20 minutes in the coldest of days.

billtwocase

Sorry, I almost always assume forced hot water, as steam is not that common here. As long as the piping is pitched right, there shouldn't a problem. I have a hard time imagining a frozen steam pipe. It would thaw immediately if it was

Jamie Hall

Strictly from the heat loss perspective, if that space is cooler it won't lose as much heat. On the other hand, there will be more heat loss through the ceiling of the second floor into the attic. On the whole, though you will lose less heat by having it cooler -- so turning the radiator off should save you. A little. Not very much.

On the other hand, while one would think that a cold steam pipe wouldn't freeze, and it might not (although I've had a trap freeze on a two pipe system) if that steam pipe is outside the insulated envelope, it will be condensing steam like mad. It may not freeze, but it will be using steam. More to the point, it will be doing that anyway, whether you are using the radiator or not (turning off a radiator does not prevent some steam from getting into the feed line, particularly if it can condense when it gets there). Is there any hope for insulating that pipe specifically?

SWEI

Any chance you can access the pipe in the porch ceiling? Insulating it would be worth a certain amount of trouble.

Kjmass1

Thanks for the suggestions. I'll probably just keep it turned off for the time being. I can probably access the pipe through the knee walls, but it will be pretty tight. Either that, or I'll have to try and rip out some of the wooden porch ceiling. I might have to save that for another day.

SWEI

Blown-in is far better than nothing.