3 ms·

A modern natural gas furnace is upwards of 90% efficient. So you’re talking about building all this infrastructure (turbine generator, heat pump, etc) to captur

A modern natural gas furnace is upwards of 90% efficient. So you’re talking about building all this infrastructure (turbine generator, heat pump, etc) to capture the remaining 10% for electricity? How does that make any economic sense? Additionally, heat pumps can already be purchased cheaply from the hardware store. These are closed systems with the refrigerant already inside. However, if you want a larger central air system then that costs a lot more because you need to hire licensed HVAC professionals to handle the construction and charging of the refrigerant loop.

bradfa 3y ago
90% efficient furnaces are kind of the low end of the spectrum of product on the market now, at least in my area of the USA. My 20 year old furnace is rated 94% efficient. Pretty much every condensing gas furnace now is going to be well over 90% efficient. Even modulating furnaces with 2:1 or better turn-down ratios can maintain over 90% efficiency when running below rated output. Locally it's not worth DIYing a heat pump install. The tax incentives and rebates easily cover the cost to hire a licensed and insured HVAC company to do the entire install for you, plus then you get to choose from a much wider selection of heat pump models which likely enable buying something better sized for your need and more efficient.
joking 3y ago
gas furnace can be over 100% now, using the condensation of the fumes to provide more heat to the water. https://www.heatgeek.com/condensing-boilers-efficiency/ https://www.heatgeek.com/condensing-boilers-efficiency/ Anyway, is more efficient to use gas for generating energy and using that energy to heat places with heat pumps than burning gas on furnaces. If you can use the residual heat of the energy generation is even better.
- sokoloff 3y ago
  That does not get combustion appliances to over unity of heat output. Condensing operation can get them to 96-ish%.

bradfa 3y ago

90% efficient furnaces are kind of the low end of the spectrum of product on the market now, at least in my area of the USA. My 20 year old furnace is rated 94% efficient. Pretty much every condensing gas furnace now is going to be well over 90% efficient. Even modulating furnaces with 2:1 or better turn-down ratios can maintain over 90% efficiency when running below rated output. Locally it's not worth DIYing a heat pump install. The tax incentives and rebates easily cover the cost to hire a licensed and insured HVAC company to do the entire install for you, plus then you get to choose from a much wider selection of heat pump models which likely enable buying something better sized for your need and more efficient.

joking 3y ago

gas furnace can be over 100% now, using the condensation of the fumes to provide more heat to the water. https://www.heatgeek.com/condensing-boilers-efficiency/ https://www.heatgeek.com/condensing-boilers-efficiency/ Anyway, is more efficient to use gas for generating energy and using that energy to heat places with heat pumps than burning gas on furnaces. If you can use the residual heat of the energy generation is even better.

sokoloff 3y ago
That does not get combustion appliances to over unity of heat output. Condensing operation can get them to 96-ish%.