The tech costs more than conventional options upfront, but federal tax credits, new 120V models and strong savings have made them more appealing than ever.
With a gas furnace and a heat pump water heater, the furnace is providing the heat for the water, and all of the electricity used by the water heater during winter is wasted, relative to using a gas water heater. Gains are only made in the summer, while the water heater is helping to cool and dehumidify the home.
Your second article discussed using heat from the dryer in a second floor laundry space. The “waste” heat from the dryer would have normally gone into heating the house, reducing demand on the furnace. The author saw “waste heat” from the dryer, but didn’t think about where that “waste” heat was going, and didn’t properly account for it in his calculations.
You cannot treat a heat pump water heater as “independent” and “separate” from the home’s HVAC system unless it is actually drawing heat from outside the home.
I am not going to argue about this as it does not help or will convince people up north how to install their water heaters.
The question isn’t where they should install them. The question is whether they should switch to heat pump water heaters at all. If using gas heat, that answer is “no”, because these just shift which appliance will be burning that gas, and use additional electricity on top of that.
The same is true for an old house with resistive or radiant heat: the heat source for a heat pump water heater in a resistively-heated house is the resistive heating. The heat pump doesn’t make the household’s radiant heating any more efficient, it just adds additional load on that system.
Heat pump water heaters only make sense where with a hypothetical “split” system that draws heat from outside the home in winter, or if the household heat source is considerably more efficient than either a gas water heater or resistive electric water heater.
Common heat sources more efficient than gas or resistive electric water heaters are heat pumps, solar, geothermal, or a climate that doesn’t require much supplemental heat. If you have any of these, a heat pump water heater will make sense.
If you don’t have any of those, you have to compare the summertime gains against the wintertime losses to find the net efficiency.
With a gas furnace and a heat pump water heater, the furnace is providing the heat for the water, and all of the electricity used by the water heater during winter is wasted, relative to using a gas water heater. Gains are only made in the summer, while the water heater is helping to cool and dehumidify the home.
Your second article discussed using heat from the dryer in a second floor laundry space. The “waste” heat from the dryer would have normally gone into heating the house, reducing demand on the furnace. The author saw “waste heat” from the dryer, but didn’t think about where that “waste” heat was going, and didn’t properly account for it in his calculations.
You cannot treat a heat pump water heater as “independent” and “separate” from the home’s HVAC system unless it is actually drawing heat from outside the home.
The question isn’t where they should install them. The question is whether they should switch to heat pump water heaters at all. If using gas heat, that answer is “no”, because these just shift which appliance will be burning that gas, and use additional electricity on top of that.
The same is true for an old house with resistive or radiant heat: the heat source for a heat pump water heater in a resistively-heated house is the resistive heating. The heat pump doesn’t make the household’s radiant heating any more efficient, it just adds additional load on that system.
Heat pump water heaters only make sense where with a hypothetical “split” system that draws heat from outside the home in winter, or if the household heat source is considerably more efficient than either a gas water heater or resistive electric water heater.
Common heat sources more efficient than gas or resistive electric water heaters are heat pumps, solar, geothermal, or a climate that doesn’t require much supplemental heat. If you have any of these, a heat pump water heater will make sense.
If you don’t have any of those, you have to compare the summertime gains against the wintertime losses to find the net efficiency.