Are you familiar with the ducting option for heat-pump water heaters?
Since Alex has been pointing out the energy advantages of using a heat pump water heater (HPWH), I thought some readers might be interested in the approach I've taken with the technology. Instead of just scavenging heat from where this unit is located, I added duct work and a centrifugal fan to draw air from the two upper level bathrooms in my home so that the heat pump was "seeing" air from the occupied space. I also added duct work on the discharge side. In this installation, in addition to the energy savings, the following benefits accrue:
1) Higher winter time temperature "seen" by HPWH,
2) Improved moisture management in a tight envelope home as significant hot water use is followed by increased ventilation,
3) Demand-based mechanical ventilation based on hot water use, which in turn is related to occupancy, and
4) Summertime 42 F air returned to living space to provide some "free cooling".
Posted Sat, 03/15/2014 - 08:33
Edited Sat, 03/15/2014 - 08:54
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