Replies

1. GBA Editor
   Martin Holladay | Jun 27, 2013 11:26am | #1

   Bob,
   John Straube has shown that exhausting stale air from bedrooms and supplying fresh air to the living room is incapable of evening out room-to-room temperature variations. For more information on Straube's analysis, see Choosing HVAC Equipment for an Energy-Efficient Home.

   In that article, I wrote, "Some people have suggested that creative ventilation ducting — for example, a system that supplies fresh outdoor air to the living room and hallway, and exhausts stale air from the bedrooms — might equalize temperatures from room to room. Straube rejects that strategy, however. 'Ventilation air doesn’t do much to move around heat,' he said. 'Ten cfm of 72 degree air to a 65 degree bedroom won’t make any difference to the temperature in the bedroom at all. Open doors work better than HRV ducting.' ”

   I advise that your HRV should pull exhaust air from the bathrooms.

   By the way, be careful when you specify a range hood fan. You don't want a very big fan. More information here: Makeup Air for Range Hoods.

2. 
   bobhol | Jun 27, 2013 11:51am | #2

   Thank you for the clarification...using the HRV to pull exhaust air from the bathroom ,do I still need a dedicated exhaust fan on a timer to get moisture out quickly...thanks,Bob

3. GBA Editor
   Martin Holladay | Jun 27, 2013 12:18pm | #3

   Bob,
   Most HRVs are designed to allow occupants to use a switch on the bathroom wall to boost the fan speed when necessary. In effect, the HRV operates at low speed continuously, and has a boost mode when needed to remove humidity or bathroom odors. Talk to the manufacturer or supplier of your HRV for more information.

4. 
   bobhol | Jun 27, 2013 12:27pm | #4

   Again many thanks....I appreciate this forum and the very professional advice ..Bob