Talk of heat, what about Cold? (1 Viewer)

[Dustin B]

There have been a bunch of posts about whether heat was a problem when using the Shiva or Tempest in an attic. The general answer has been that Dan says a Shiva would be ok for a car, so an attic won't be a problem.
My question though is what about cold. I'm in Saskatchewan. It's not abnormal for us to see temperatures below -40 celsuis during the winter. How would a Shiva or Tempest take to being placed in an attic for an infinite baffel config when the temperature can get well below freezing?
Just for shock value to those who have never been up north to a flat open area with no large bodies of water around it I'll give a few other temperature numbers and their converstions to F. -40 C is where the F and C scales match up. Several years ago there was a two week period where I had to walk to school when the temp was between -45 and -50 celesius and with the wind chill it down to between -60 and -65 celsuis.
-45 C = -49 F
-50 C = -58 F
-60 C = -76 F
-65 C = -85 F
And to top it off we see temps over 40 C in the summer
40 C = 104 F

 

[Richard Driskill]

Dustin,
At roughly -31F I would not do it, it's just too cold. What you might do is insulate the area around it, but that would negate the infinite baffel. And what about that extreme cold seeping through to your living area? Cold "sinks".

 

[ThomasW]

I doubt that the attic temperature will be that cold, given the proximity to the rest of the house .
Also remember that the IB itself whether you use just a raw driver or a manifold/plenum configuration will act as a chimney. As a result the warm air from the house migrate up through the cones unless there is a "trap door" that can be closed.

 

[Dustin B]

Hmm, two posts, two different opinions
I'm not sure how cold the attic would actually get. The insulation is the spray in type and just rests on the ceiling. So I'd guess the insulation prevents the house from transferring to much heat to the attic. So I'd guess the attic would actually get pretty close to the outside temp (minus the wind chill of course). Maybe next winter I'll throw a thermometer up there and see for sure.
Now would cold sink through it, or would heat rise up through it. Either way I guess it would cause the heating bill to go up. Also a drap door would be quite annoying and probably would get the whole driver to be very cold.
What concerns me more, if by some miracle I ever decide to do this, is added friction to the drivers movement since the cold will have shrunk it and whether the surround would crack from being moved while very cold and stiff. I'm thinking about when I touch my doors or windows, the house is warm inside but those surfaces are very cold (so I don't know if rising heat from the room would be enough). Although maybe the window and door are just barely above 0 C and its just the 20 degree C difference in temp that makes them feel like they are freezing.

 

[ThomasW]

Heat rises, cold doesn't "sink", at least in this situation.
I think you'll find that the attic is considerably warmer that the outside temp. Especially if you have something like R-30 blown-in insulation.
But there are situations where an attic mounted IB isn't practical and your's may be one of them

 

[Dustin B]

The more I think about it the more I agree with you. It is the hot air rising which has to be replaced by air that isn't rising, which will just result in the creation of a little bit of circular air flow in the room. So with an opening as small as the hole for a IB sub in the attic, heat will rise into it and cooler air in the house, not from the attic will replace it.
But if the cold will toast the surround on the driver I guess I'm out of luck. Although since I likely won't be here for much more than 3 years I think it would be unwise to deface the living room like that anyways.