I've got a question that I'm a bit perplexed about and I'm hoping that I can get some comments.
I've got a 2850 square foot area where we will be installing an HRV (new contruction). There are 5 bedrooms, a media room, living room and dining room into which we want to push in clean air. For stale air returns, I was wanting to have one in the master bathroom, one in each of our two full bathrooms and one in our powder room. We will also install one at the top of the stairway for the final stale air pickup. We will also install regular (low noise) bathroom fans in each bathroom for those higher use times (bath/shower, smells, etc.).
The HRV contractor told me his supply house guys informed him that if we install stale air pickups into our bathrooms we WILL have smell transfer problems. He was told that WHEN THE HRV IS NOT RUNNING (e.g. summer time, when the HRV is on a 20-minute on - 40-minute off schedule, if the HRV breaks down, etc.), there is a risk of smells from one bathroom traveling to one of the other locations where there is a stale air pickup. When my wife heard this, she became adament that she does NOT want to install any stale air pickups within any of our bathrooms. My concern is that the bathroom air will become stale over time if the bathroom (and regular fan) remain unused and there is NO HRV stale air pickup for that bathroom.
Am I way off base of is the information the contractor received bogus? I asked him and he said that he has never installed stale air pickups into bathrooms for any of his previous jobs. However, he said he would install the system that way if we want it. This is a smart guy when it comes to calculating the installation flow and balancing the system, but I'm look for information from folks with experience having HRV stale air returns within bathrooms or for folks that may know where there may be information about this posted online (at least as far as smell transfers goes)? There is a lot of information that talks about having the HRV pickup air from bathrooms, but nothing about a potential for smell transfer if the HRV is NOT running.
My question is this: when the HRV is NOT running, could smells from one bathroom travel within the HRV stale air return lines to somewhere else within the house? Remember, this would ONLY occur if the HRV were NOT running. If it's running, there really should be no issue as far as I can tell (logically anyway).
There really are only a few times that I could think of during which the HRV might not be running. For example in the summer we will most likely turn it off or put it on a very reduced schedule as my wife likes to open windows and doors for ventilation. Or if it breaks and has not yet been repaired. Other than that, I think we'll keep it on most of the time or keep it on a 20-minute ON - 40-minute OFF schedule (city requires 8 hours continuous running each day).
All questions or comments welcome!