• Acters@lemmy.world
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    10 months ago

    This is example highlights the benefits of heat pumps as the heat from the gas furnace is waste heat from something functioning on an entirely separate purpose that will occur independently from the water heater. In turn this situation benefits the heat pump as it is actually more efficient to scavenge the wasted heat from the gas furnace. It is super odd that your post is suggesting that it is not efficient because it is using “extra electricity” when the efficiency is from reduced running costs(money) and not hype fixating on just electrical usage. On the flipside, a gas water heater will use extra gas to heat the water, too! This is just silly

    • Rivalarrival@lemmy.today
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      10 months ago

      A furnace puts BTUs into the house. A heat pump furnace pulls BTUs from the atmosphere and pushes them into the house; a gas furnace extracts BTUs from fuel and puts them into the house. An electric furnace extracts BTUs from electrical energy, and puts them into the house.

      The heat pump water heater pulls BTUs from the house and pushes them into the water. They use internal air as their heat source. They do not draw heat from the outside atmosphere; they draw heat from the furnace-heated air inside the house.

      The two systems are not “separate” or “independent”. The heat pump water heater is daisy chained to the furnace. Both use the same, household air for opposite purposes: one sinks heat into the house, the other sources heat from the house.

      • Acters@lemmy.world
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        10 months ago

        And how is it a bad thing that it is making good use of the heat around the furnace to heat up water? You do realize that the electricity in the heat pump also is making some heat on its own.

        All that energy can be harvested for a hot shower or bath instead of having a heat pump outside in the colder temps running at a lower efficiency. On top of that, the furnace will not always be running throughout the year, and the warmer months will be more beneficial to have the heat pump than a gas water heater.

        I am assuming that the heat pump water tank and gas furnace are in the basement, or garage. not inside the well insulated house…

        On top of that, the hot air is directed out of the gas furnace to the house, while the air surrounding the gas furnace is lost heat that can be scavenged by the heat pump. They are independent and work for separate reasons.

        • Rivalarrival@lemmy.today
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          10 months ago

          I am assuming that the heat pump water tank and gas furnace are in the basement, or garage. not inside the well insulated house…

          Ah. That’s the issue. Your assumption is faulty.

          Water heaters have water lines leading to them. Anywhere the temperature regularly falls below freezing, the water heater must be located inside the heated structure, not exposed to the elements. Otherwise, the plumbing could freeze. The basement may be colder than the rest of the house, but it is still part of the heated structure.

          If your basement, garage, or whatever room contains your water heater is not within the heated structure, you are living well south of Ohio.