Around 2k-3k. I don’t know how the controlled residential ventilation warranty is affected if you install it yourself. But by sourcing it yourself and installing it yourself, you can certainly save some money.
P.S. Your controlled residential ventilation system shuts off at -7 degrees? Why is that if so?
P.S.S. Why does a controlled residential ventilation system always have to have a EWT in your opinion? There are other very good solutions that work just as well
Without an EWT, the ventilation system already throttles at -1° and then eventually shuts off. Unless you install a preheating coil beforehand...
Because all other solutions do not work as well and passively – quite simple.