Keeping ERV, makeup air and range hood ducts AIRTIGHT
I am 2 days away from my blower door test and 8 months into our custom home build in Northern Wisconsin. We’ve (I think) impeccably detailed a contiguous air barrier and covered all our bases. There’s no combustion in the home and we’ve selected appliances with as little venting as possible (heat pump dryer and water heater, etc.).
That said, I have (4) 8″ ducts coming through the wall:
– ERV intake
– ERV exhaust
– Range hood makeup-air
– Range hood exhaust
The HVAC team installed mechanical dampers today on all 4 as that was going to be my solution to keep these as airtight as possible, however, upon inspection, well, see the picture… Each damper has two nickel to quarter size gaps around the shaft that are going to contribute greatly to infiltration/exfiltration.
Is the ERV system actually already airtight at the ERV unit itself? Meaning, if I seal the ductwork up to the ERV, will the box itself provide airtightness?
Are there better airtight mechanical dampers? What are my options to shore up this potential major leak?
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