Heat pump water heater in an unconditioned attic… any issues?
I’m working with a builder building some townhomes in Orlando. One option is for them to install heat pump water heaters in the unconditioned attic (R38 blown cellulose floor). There are a couple concerns I have:
1. Will it be too cold in the winter? The 97.5% heating design temp in Orlando is 38F. I expect this, plus the small temp buffer from being in an attic, should make freezing not a problem. Does anyone have experience with this?
2. Due to height restrictions, the water heaters would have to be installed in the middle of the attics. This means there will be a large moment in the truss members, so they will have to increase the size of the members. Has anyone seen either a short (~3′) heat pump water heater or one that can operate on its side?
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