Make-Up Air Heaters to Balance a Range Hood
I’ll be breaking ground this Fall for a new home in Maine that will be small (1,214 sq ft) and super-insulated. Heatload requirements are estimated to be around 9,100 Btu/h in the dead of a Maine winter to keep the place at around 72F. One challenge I’m facing is maintaining the thermal efficiency of the home when using a gas range top and ventilation hood on a regular basis. I’m an avid cook committed to cooking with gas and have pieced together a Make-Up Air system that I believe will pull in and preheat air in the colder months at a rate equivalent to the amount of air being exhausted by the range hood. I want a solution that will eliminate the possibility of bringing a cold blast of air into the house every time I use the range top in the winter. Also, if I do install such a system, I curious to know if I should have the incoming air vented directly into the kitchen or whether it would be sufficient to have it brought in through the basement.
Here are the specifics for the system:
1) 36″ LP gas range top that will likely never be burning more than 60,000 Btus at a given time
2) 42″ range hood with 600 cfm inline blower (sized for a maximum of 65,000 Btus) venting to the outdoors
3) Self-contained 10 kW (600 cfm) make-up air heater and intake
4) Automatic make-up air damper with digital controls
There will also be a Zehnder ERV in the house running at all times and exchanging air at a rate of 78 cfm (9 to 10 air exchanges per day.)
Is a Make-Up Air system like this overkill? Are there other less expensive or more reasonable options (short of cracking open a window) that I should be considering?
Finally, in there not a way to harness any of the heat produced by the range top to help preheat the make-up air being pulled into the house, much like a GFX recoups energy from a shower drain? Simply blasting that heat out of the house seems like such an incredible waste of energy that should somehow be able to be recouped, if even just partially.
Thanks for any feedback or suggestions.
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