Replies

1. 
   user-626934 | Jan 02, 2012 05:22pm | #1

   Yes, you can do this, but you don't necessarily have to install the booster switches. Design these exhaust branches to the code required continuous exhaust (typically 20cfm for bathrooms), then install and test/balance the airflows.

2. 
   jnarchitects | Jan 02, 2012 05:56pm | #2

   Here is a link to a previous discussion. I would agree with John above. Many HRV/ERV's offer the ability to increase fan speed when necessary via a point source switch.

   https://www.greenbuildingadvisor.com/community/forum/mechanicals/18285/hrv-bathroom-exhaust-fan

3. GBA Editor
   Martin Holladay | Jan 02, 2012 06:52pm | #3

   My vote is to stick with the ERV -- don't install separate exhaust fans in your bathrooms.

4. 
   Yxb7CwDmob | Feb 28, 2012 06:49pm | #4

   You maybe required by code to have seperate ventilation for bathroom due to contamination build up in an air to air exchange ventilator, which could cause sick building sydrome or mold propagation. check with local building code and or International Residential Code

5. GBA Editor
   Martin Holladay | Feb 29, 2012 07:44am | #5

   Thom,
   There are no such prohibitions in the International Residential Code, to the best of my knowledge. Please cite a relevant section.

   According to section M1507 of the 2006 IRC, bathrooms need at least 50 cfm of intermittent exhaust ventilation or 20 cfm of continuous exhaust ventilation. The exhaust air must not be recirculated into the house or discharged into an attic or crawl space. An HRV complies with all of these requirements as long as it provides either 20 cfm continuous exhaust or is capable of 50 cfm of intermittent exhaust.