The last thermal bridge
fourforhome
| Posted in General Questions on
After we have broken every thermal bridge in our latest project house with double studs or continuous exsulation and our slab is a barge on a sea of rigid foam, the only thermal bridge that remains is a piece of metal with a large surface on the inside to conduct our heat to an equally large radiator on the outside. We put one (or two) on every exterior door.
What to do about the doorknob?
Is there such a thing as a thermally broken doorknob (that still looks respectable) for a front door?
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Replies
Mark,
I don't know of a modern latch that is thermally broken. In Alaska, it's a useful gauge of the outdoor temperature -- when there is lots of ice on the interior doorknob, you know it's cold outside.
My friend Bill Gessner built a wooden door with an elegant wooden latch that pulls the door against the weatherstripping. No thermal bridge.
Here in Vermont, we don't lock our doors. If you need to lock your door, you could always install a hasp and padlock on the exterior -- no thermal bridge there.
I access a commercial door where the handle is just something to hold on to - it doesn't penetrate the door . All latching and locking functions are done electronically.
As new additions of building codes here in Western Canada have been updated, they have been including the requirement that exterior doors have triple-latch locking systems. I can't see how they could be made to include a thermal break.
Except for the perhaps unpleasant feel of a cold doorknob, is this really something to worry about? The energy penalty is unmeasurable.
Good enough, then.
You forgot the front free hose bib.
Also, is there any way to air seal the door knobs?