One of the special challenges of building a Passive House is heating it during construction. The standard solution for temporary heat is a portable forced-air propane heater, but there are two reasons why we can't use one of them:
They put out a tremendous amount of moisture, which would take ages to dry out in a tight house.
It would release a lot of nasty combustion chemicals into our building envelope.
But it's winter in Vermont, and our various crews and subs are oddly cranky about working in a frigid building. So we had to come up with something.
Once again, it was Eli to the rescue. He somehow found a weird exterior heating device, and we're pumping the heat into the house through a temporary hole in the floor. This puts the combustion outside but fills the house with delicious heat. (Note that we have to open a window first, or else there's nowhere for the warm air to go.)
It's cantankerous little devil — Eli spent the better part of a week getting it to work, seeking advice from a wizened engine guru of his vast acquaintance. Ted and I live in vague fear that it will either (A) stop working or (B) explode, but we are also grateful that it has shown up to lend us a hand.
In other news, the garage is nearly complete. Mark and Luke (from Eli's team) will start the roof edge trim later this week, and the roofing will soon follow. Windows and doors will arrive by the end of the month, and we look forward to being able to store stuff inside. I'll upload more garage photos soon, since it's truly a cool and wonky little building, deserving of its own post.
Here's a photo from this morning. Can you spot what's funny about it?
Ordinary houses breathe through leaky joints and poor seals, losing heat and wasting energy. But our house won't leak, so we'll use a heat recovery ventilator (HRV) to admit fresh air and expel stale air, transferring heat from one stream to the other.