HPWH without ducting was installed in the first house.
Also, the use of HPWHs in the two lab homes had limited cooling effect on the indoor temperature.
If a home had a basement, that was a ssumed to be the unconditioned space location where the HPWH was installed.
However, it does not take into account any impact of the HPWH on the HVAC equipment or whether the HPWH is fully meeting the load.
Third, it may be practical under certain conditions to recover work from the expansion process in a C[O.sub.2] HPWH
to offset the power requirements of the compressor and, thereby, improve efficiency.
Enviromaster International (EMI), Rome, N.Y., a supplier of residential and light-commercial air-conditioning systems, was found to have the technical and product development skills needed to take the market-optimized HPWH
from ADL's laboratories into consumers' homes.
The integrated C[O.sub.2] HPWH
was tested in the laboratory as well as in a field simulation, at a controlled and monitored residence near Knoxville, TN.
In the heating season, the additional space heating load due to HPWH
operation (difference between the average WH heat transfer in the HP mode and the standard mode) is 6685 W h/d.
In addition, HPWH
modeling is examined to compare the existing modeling method to a laboratory study.
Backed by the Department of Energy (DOE) and the Environmental Protection Agency (EPA), integrated HPWH
technology was added to the Energy Star program in 2008 (CEC 2011).
While all classes of residential water heaters have shown variations in performance and efficiency when put through DOE certification versus hot water draw patterns more representative of actual use in homes, the HPWH
may have large variations.
The savings for the HPWH
levels are higher, but half of the households would experience a net cost (LCC increase).