I am in the process of designing a tight house with ICF and triple pane windows and spray foam non vented attic. I was told that it may be a challenge to put a 6 burner gas oven in a house that is very tight. Can this be of a concern? I understand the hood needs to be vented outside. But what about when the unit is not being used?

I have a 5 burner propane cook stove in a very tight house (1.4 ach50) and have no problems with it. It is ignition lighting so no pilots. I do use my vent hood when cooking and supply make up air by cracking open a window since I don't have an hrv/erv. But this is just to facilitate removing moisture and cooking smells, not due to any problems with the stove itself.

-Rosalinda

Thanks Rosalinda, Can a HRV make up for the exhaust fan?

That can happen if the HRV is running, although this may be somewhat dependent on the particular unit. I know on ours (Lifebreath 195ECM) that happens. The range hood tends to depressurize the house, especially if the house is tight. Before the incoming air duct from our HRV was connected to the rest of the distribution ductwork, the fresh air from the HRV just dumped into the basement air space. If you put your hand up to the HRV outlet, you could feel the difference in temperature of that air immediately when the range hood was turned on, indicating a big drop in outgoing air flow. The mfg didn't really want to give a direct answer to my question on whether this would happen, as the unit isn't really designed to work that way. I just found that the HRV (ours anyway) does become imbalanced and the outgoing flow does drop due to the depressurization. We also had to turn off the HRV for the blower door test, as that was an even bigger depressurization.

There were several discussions over at greenbuilddingadvisor.com on this subject. I recall at least one HRV manufacturer being quoted as stating it will NOT make up the difference as it is a balanced system. I would not risk depressurizing your house if you have any other gas-fired or wood-burning appliances (sealed combustion or not). There were several decent suggestions including interlocked motorized dampers to allow outside air to enter the house when the hood is in use. When not in use the dampers would remain closed and be relatively airtight. I would take a look and see if any of the suggestions will work for you.

Thanks for the info. It appears that if this is not though out properly it can be an issue.

You need to exhaust the gas stove, and create a way for make up air to enter the house.

One effective idea I've seen is a duct that provides outside air situated under the range. You would install a makeup air damper.

Air is drawn into the house by the stack effect and negative pressure created by the range vent.

It'll also minimize the amount of mixing your clean conditioned/heated indoor air will have with the dirty air or the clean but unconditioned/heated outside air.