Makeup air, I think I built our house too tight.
We recently finished our 1260sqft, single level house. Lots of attention to air sealing. I never had a blower door test done, based on wingnut evidence.
Some quick details:
-Zehnder CA200 ERV
-Zephyr Ak7136AS 210 – 400CFM vent hood.
-JennAire Induction Cooktop
-Electric (non-heat pump dryer)
-Kuma wood stove with makeup air kit installed.
-Mitsubishi Split units
The only “combustion” appliance in the house is the wood stove, which is only used occasionally (two times total as of now).
When using the vent hood on low (210CFM) the house gets depressurized to the point that there is a noticeable change in fan speed/load/noise when opening a door or window. We have taken to opening a door or window when cooking, providing makeup air and allowing the vent hood to work.
This is my ‘wingnut’ air sealing testing, I felt pretty comfortable with the air sealing without paying for the blower door test.
Now that it’s colder, opening a window makes the kitchen cold, we’ve started opening windows on the other side of the house, which works, but makes that side of the house cold.
Of greater concern was last weekend, I had built a fire, catalytic burner engaged, was burning nicely. Vent hood turned on, and the fire visually went out. Opening a window caused the fire to start burning normally again. I checked the outside air inlet with the fire burning, it had air flow through it (extra scientific back of hand test)
What’s the best/least energy penalty method to have makeup air? Currently looking at 6″ motorized damper, T- into the ERV – exterior ducting. Either switch controlled, or using CT relays arranged in an OR circuit, sensing vent hood and dryer.
I’m also a little concerned that we’re wearing out the exhaust ECM fan on the ERV. Not realizing that the dryer/vent hood needed extra makeup air, the extra load/ DP the exhaust fan has been working against. The ERV has gotten louder (although it may be my imagination). ECM motors should be basically silent, and the exhaust side is louder than the intake.
I can post some videos showing noise change, fire effects if interested.
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