Replies

1. 
   HammerHarry | Apr 29, 2008 01:21am | #1

   I would absolutely NOT tie the kitchen vent into the hrv, unless you like cleaning sticky greasy crud from the core of the hrv every couple of months.

   I would tie the bathroom fans into the hrv, it's simply moist air.  Typically here (NB Canada) the bathrooms have a switch that kicks the hrv on for x minutes.

    

1. 
   TroutMullins | May 06, 2008 10:15pm | #2

   Any other thoughts about clothes dryer air intakes?

2. 
   dovetail97128 | May 07, 2008 01:30am | #3

   Yes

   Yes

   No

   Yes, but only on a timer and with sealed duct work.

   They can't get your Goat if you don't tell them where it is hidden.
3. 
   shelternerd | May 07, 2008 04:25am | #4

   Provide outside air intake for clothes dryer yes, 6" "sock damper"

   -Provide outside air intake for gas fireplace? yes buy direct vent model

   -Tie kitchen exhaust hood into the HRV? no

   -Tie bath fans into HRV? no

   For more detail...

   http://www.chandlerdesignbuild.com/files/ventingStandardsComplete.pdf

   be well

   M

   ------------------

   "You cannot work hard enough to make up for a sloppy estimate."

1. 
   NRTRob | May 07, 2008 06:04pm | #7

   where exactly are you getting this 7.5 cfm per occupant standard?That doesn't mean any standard I'm aware of for residential construction. ASHRAE requires 15 cfm per person as a minimum, or 0.35 ACH capability, whichever is higher. I think it's 0.35ACH is high, personally, but 7.5 cfm/occupant seems a bit low.-------------------------------------
   -=Northeast Radiant Technology=-
   Radiant Design, Consultation, Parts Supply
   http://www.NRTradiant.com

1. 
   shelternerd | May 08, 2008 01:13am | #8

   BobThat was coming from energy star and the national green building standard. I'm sure it's debatable but it would be in addition to natural air exchange in the building. Gotta start somewhere and 45 minutes at 100 CFM every four hours per person on top of the natural drafts in the house seems like plenty to me. But I'm just a builder, not a scientist. Be well, you going to the NAHB green conference in New Orleans next week? ------------------

   "You cannot work hard enough to make up for a sloppy estimate."

1. 
   NRTRob | May 08, 2008 04:22pm | #9

   Sadly, no. I bet it will be a good time though.Natural drafts in tight homes can be very, very small indeed. but I just looked up some research which indicates an average person walking at 2mph only breathes about half a CFM. so maybe your 7.5 CFM number isn't as crazy as I thought at first blush. obviously there is more than respiration at work, but that's 7 cfm for added stuff.sure will be nice if someone comes up with something definitive some day...-------------------------------------
   -=Northeast Radiant Technology=-
   Radiant Design, Consultation, Parts Supply
   http://www.NRTradiant.com

1. 
   Jay20 | May 08, 2008 05:27pm | #10

   I wrestled with this issue in my house since I am tightening  it up. I found a lot of information on the American Lung Association web sight. You might try there. Jay

4. 
   Jeff_Clarke | May 07, 2008 05:28am | #5

   Well, first of all you have to decide whether or not you need an HRV or ERV (Energy Recovery Ventilator).   Depends on your heating/cooling zone.

   We have an ERV (Trane) 130 CFM and it works great.   Exhausts from a 2nd floor ceiling and provides fresh air at a fixed point on the second floor a bit away from the exhaust.   It's effective enough that when it's 20-30 degrees outside we get 63-65 degree air from it with only the exhaust air warming it.

   It's a relatively tight house, especially with foamed insulation.

   Kitchen exhaust is variable speed (up to 1200 cfm) and for outside air I have installed a Honeywell EARD5 motorized damper (24 VAC) activated by a current sensing relay (CR Magnetics - necessary since the fan is variable speed) so that when you turn on the fan the relay senses current and opens the motorized damper.

   No combustion air for the dryer needed, although I could run that through the relay too since the intake grille is in the same vicinity.

   Jeff 

   
   

   ---

   Edited 5/6/2008 10:44 pm ET by Jeff_Clarke

5. 
   IdahoDon | May 07, 2008 06:46am | #6

   The better you can be at reducing sources of stale air and venting those areas, the fewer air exchanges will be needed.   Some of the tightest houses in Colorado have nothing but the dual mode Panasonic bath fans to control indoor air quality.  The slow speed constant venting fans are adjusted as the seasons change so they keep stale air to a minimum but not break the bank. 

   There is a significant amount of interest in tight, well insulated homes and not all of it suggests a heat recovery ventilator is cost effective.  It can provide better air quality and that is worth something, but there are thousands of tight houses that are economical to heat and don't have a HRV, but rather use a well thought out system of simple vents.

   Best wishes

    

   Beer was created so carpenters wouldn't rule the world.

6. 
   Clewless1 | May 21, 2008 11:39pm | #11

   Code may not allow tying range hood to HRV. And for good reason.

   Direct vent gas fireplace ... no muss no fuss ... this is standard in the industry.

   You could provide make-up air for the dryer ... use a motorized damper interlocked with your dryer circuit ... opens when the dryer is on.

   Definately ... ALWAYS tie bath fans to the HRV!