6 Comments

1. 
   Interested Onlooker | Jan 27, 2010 08:40am | #1

   If I remember correctly, the
   If I remember correctly, the favoured solution in Europe is to use a recirculating cooker hood which traps the grease locally. You have to clean the hood filters every six months or so, depending on how often you cook. The odours, moisture and by-products of combustion are then removed through the HRV.

2. 
   Anonymous | Jan 27, 2010 01:54pm | #2

   Leave the kitchen hood on,
   Leave the kitchen hood on, but open a window near by if the fireplace is on... Simple easy and low cost.

3. 
   Baltimore Green Construction | Feb 01, 2010 08:39am | #3

   Don't leave the range unducted
   I disagree with Derek's advice. Ranges should be ducted to the exterior.

   Filters will remove some small fraction of smoke, if something starts to burn. But they won't remove water vapor from a boiling pot, and they certainly won't remove combustion byproducts if you have a gas range (which is very common in many parts of the country).

   I think it's reasonable to expect that air will leave your house when you cook, because for health and moisture reasons it really needs to.

4. 
   Derek_Vander_Hoop | Feb 04, 2010 08:22am | #4

   Baltimore Green
   Baltimore Green Construction,

   I was misquoted in that I never "advised" anyone to use a recirculating filter. I did post a photo of what I thought was a perfect solution and offered it to Kevin and the Green Building Advisor community. Having said that, if I was building a Passive House today, I would use this method.

   If you have a PassivHaus, it makes sense to remove the grease and smoke while cooking and then gently exhaust the odors, moisture and stale air through an ERV and HRV (which Kevin is using), recovering the heat in the process. To me, this is a far better solution than forcibly exhausting 600 CFM of air, losing heat energy in the process and throwing pressure balances out of whack.

   I wouldn't use a gas stove in a Passive House, and I'd do my grilling outdoors, for obvious reasons.

5. GBA Editor
   Martin Holladay | Feb 04, 2010 09:13am | #5

   Thanks for your clarification
   Derek,
   Thanks for your helpful post. I've edited the section that summarized your views, in light of your clarification.

6. 
   Whetstone Green | Feb 11, 2010 08:46pm | #6

   high CFM exhaust bad idea in super efficient homes
   First off, I agree with others that connecting a cooktop exhaust system to an HRV is a bad idea. Aside from other arguments presented, 600 CFM would overwhelm the capacity of virtually all residential HRV's, thus greatly reducing the efficiency (heat recovery fraction). And any dirt that accumulates on the heat exchange substrate will drop efficiency even further. Since a cooktop fan only operates a fraction of the time, I can't imagine a scenario where a dedicated HRV would be cost justified.

   I agree with Derek that a gas range has no place in a PassiveHaus or any other super high performance home. Electric ranges are perfectly happy with a 200 to 300 CFM hood. Downdraft fans require more airflow to overcome gravity, and should be avoided. Of course, this all requires customer education (Don't tell my wife she can't have her gas cooktop on an island!).

   Here in the US, commercial style 6-burner gas ranges have become very popular in high-end homes. Having long given up on convincing clients to go electric, I at least advise against installing one of those ridiculous commercial range hoods that pull up to 1200 CFM. These are required in commercial kitchens to meet OSHA requirements but have no place in the home. 300 to 400 CFM is plenty for a oversized cooktop. Unfortunately, 5-Star, Viking and other manufacturers haven't got that message. If you want your hood to match the range, you may not have a choice. These obviously require local make-up air. The best I can do is tell clients to only turn them up as far as necessary to draw in the steam/smoke, and to avoid using the highest speed when it's particular hot, humid, or cold outside.