Central fan integrated supply + Range Hood/Make-up air
Building a “pretty-good” house in Zone 5
* 2″ exterior foam with taped and staggered seams
* r-15 mineral wool in interior
* attic will be conditioned with 4″ closed cell foam and mineral wool
I can’t know before the blower test how much leakage there will be but assuming the house will do well on the test.
The current plan is to use “central-fan-integrated supply ventilation system” with HVAC unit with a variable speed blower in the attic and basement each with a ductwork with motorized damper to bring in fresh air.
The S.O. is insisting on a big commercial style range requiring a large high CFM hood (I would change this if I could but some fights are not worth having). I have looked at Martin’s 2010 article on the large range hoods required by these monsters:
“Make up air for a residential hood” https://www.greenbuildingadvisor.com/blogs/dept/musings/makeup-air-range-hoods?page=2.
This makes me a bit concerned about backdrafting. In the article (2010) the manufacturers seemed blissfully ignorant about the make-up air issue, however today I see many of the manufacturers recommending motorized dampers and external make-up air sources in addition to the hood which is a step forward.
In my case since I will already have a fresh air source with a motorized damper and I was thinking if I have the hood open the damper for the HVAC system to make-up air to be drawn in through the existing ductwork. This would a)save a little bit of money/time and b) have the make-up air distributed through-out the house which would be better on days with extreme temperatures as the cold/hot air would not be concentrated in one area.
My question to the GB crowd is does this seem reasonable? and will the approach pull in enough make-up air through the ductwork when the HVAC motor is not on or could it still possibly cause backdrafting??
Thanks in advance
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