HPWH – Loud and smells like dirty socks
I’m at a point where I’m seriously regretting getting a heat pump water heater.
For one, it’s very loud. It’s in in the laundry room, but when it’s on, you can hear its high-pitched compressor noise through the rest of the house. Unlike a window AC, they’ve put almost no effort into making it quiet.
But the other issue is that it smells like dirty socks when it runs. It’s in the same room as my heat-pump dryer, and I don’t want to use mildew air to dry my clothes, so now I operate it in resistance heat mode instead of heat-pump mode, saving me nothing.
I suspect, possibly, that co-locating the HPWH and the ventless dryer is actually a recipe for microbe growth. Microscopic lint gets kicked out of the dryer and pulled into the HPWH coils where it settles and lets microbes grow. Or is a issue with most HPWH, which sit with moist coils, but people keep them in basements and garages where the smell isn’t noticed?
So, am I stuck paying someone to regularly clean and disinfect the coil (if it’s even accessibly enough to be done), or operating it in resistance heat mode?
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Replies
IMO, any device with a heat pump needs to occasionally blow air over the evaporator coil with the compressor off. This dries the coil and deactivates mold.
Good point that lint from a heat-pump dryer may make things worse.
Apparently HPWHs often cool without removing much moisture. This could lead to too high %RH, creating a smell problem in the entire room (vs just the coil). Your dryer may also create excessive room humidity.
Check that nothing is blocking the condensate drain, and that the unit is level (no condensate dribbling where it shouldn't be). Clear any blockages you find. There are biocide cleaners to use on the coils that will sterilize things. With a little luck, the problem won't come back, but I'd keep an eye on it.
Bill