I just saw an advertisement for heat-pump water heater (HPWH). Yes, I understand things like SEER, EER, HSPF, but where does it get the heat? If I have a HPWH in my house, won't that make my heating system expend more energy to keep the house warm (or does the condenser go outside like my A/C)?
Note: I realize that's a benefit in the summer time when my A/C is trying to keep my house cool.