HPWH, HRV, bathroom vent, stove-top vent, make-up air, and balancing house ventilation
So ventilation or rather balanced ventilation seems so distant, especially when using a comprehensive ventilation strategy for all the appliances that need ventilation.
The house will be built in zone 6A, and is all electric, with PV – hoping for Net Zero.
I’m going with a HRV (Zehnder ComfoFond-L), and a stove-top vent hood for an induction stove (low CFM (250ish), it’s hard to find a lower CFM hood). Energy Star or their other newest program “Net Zero Ready” certified homes won’t allow the HRV to operate by themselves without also having source ventilation in the bathrooms….so I’m going to have bathroom vents too I guess, and I’m hoping to use a HPWH instead of a SHW system.
While at Building Energy 15′ in Boston this year someone mentioned a good way to temper make-up air for a stovetop vent hood is to place the incoming make-up air vent at the bottom and behind the fridge, so that when it blows over the coils the cool air will make the fridge more efficient and temper the incoming air also….this only works in the winter though – even in Zone 6A.
So if I did this with my HPWH it would work all year round. Some of the HPWH even have ducted kits available as options. Would the CFM that the HPWH puts out make the kitchen uncomfortable or would the fridge temper the air enough? Would this throw off the balance of the house?
I’ve also considered ducting the HPWH outside. I wouldn’t have the intake ducted from the outside here in zone 6A, but would have the outlet ducted to the outside. Would this throw off the balancing of the HRV or balance of the house?
Or should I just forgo ducting to the fridge or to the outside, and use the HPWH like I planned initially – to duct it too a cool food storage room in the basement. The basement is insulated under the slab (R20) and on the walls (R30). I would probably insulate the ceiling above the cool storage room too, so it didn’t make the floor above cool too. I guess I could put a passive vent in that would discharge behind the fridge right?
What balancing issues am I missing?
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