I am trying to figure out if its a good idea to exhaust bathrooms through an HRV in a new house we are constructing soon. Theoretically this seems possible with humidistats connected to an HRV with multiple speeds (and with short duct runs), so that the high flow rate bathroom ventilation rate of 50-150 cfm can be achieved when needed and the HRV can then revert to a continuous low exchange rate when bath ventilation is not required. I have found this mentioned in several magazines (including the recent FH “Houses Need to Breathe.. Right?” article) though they all run the HRV on the intake for the forced air furnace, and since we will have hot water radiant heating we will not have an “already needed” duct system. Is there any reliable information about such a system or any other concerns that would make it inadvisable (such as water condensation inside the vent pipes or HRV from steam removed from the bathrooms). Thanks! Also is this going to be really expensive and I’d be better off just putting in bath fans and some passive wall vents for make-up air?
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I use our hrv to vent the bathrooms, it works fine.
As do we. Exhaust air always coming from the bathroom. I also supply fresh air there. Turning on the bath fan speeds up the process.
A decade later, I don't see a downside. PAHS Designer/Builder- Bury it!
If your duct runs from the baths to the HRV aren't long this isn't a big issue. However it can be a nightmare if you haven't planned for it in the framing. Simply get a HRV that's built to do just what you've described and it takes all the guesswork out of the process.
Beer was created so carpenters wouldn't rule the world.