Is there a way to vent a downdraft cooktop without having to punch a hole out the wall. I'm not thrilled with having to do this due to the heat loss and/or cold drafts from the vent. Furthermore, I have ICF cement walls, so it's a bit of a job. What about tying it into the ducting of my fresh air heat exchanger? What lead me to this thought was some very sparse information elsewhere where they said you could wire the cooktop fan switch to turn on your furnace blower, but haven't been able to find any further detail on what they were getting at.