Hello!

I have a few unrelated questions to mechanical ventilation. I am looking to ventilate a new build house with a low ACH goal (.75). 2100sq ft of living space with 4 occupants. ASHRAE says I need about .93cfm, so naturally I’m going for 200-250cfm (just for the boost mode, lol!). Plan on getting an ECM unit and run it in that 90cfm range continuous.

This is in Western Colorado (5a)- Hot dry summers and cold dryish winters (higher outdoor RH in the winter than summer).

1) I’m leaning toward HRV systems, although it’s hard to judge without actually living in the house.

2) Has anyone had experience with the CERV? It’s quite expensive, but has some cool features. Here are the units I’m looking at. Because of the area summer bypass would be great, which I think only the first two have:

Equinox CERV
Zehnder COMFOAIR 350
Fantech HERO 250H-EC
Broan HRV200TE

3) Here’s the random one: Does anyone know what happens when I put a negative pressure on the house with a low powered range hood? I am planning a ~300cfm range hood so that I don’t have to mess with makeup air, but I know this may do some weird stuff with the balance of the MVHR system. Build Equinox can be programmed to run unbalanced, but I can’t get info on what happens to the other systems.

Thanks!