Heat pump

An electric heat pump is one way to heat a building. It works a lot like air conditioning but in reverse: The hot air goes indoors; the cold air goes outdoors.

Energy usage

Moderate

Heat pumps are more energy-efficient than electric heaters.^{[QUANTIFICATION needed]}

Research needed:

• How much more energy-efficient can a heat pump be?
  • How does this depend on outdoor temperature?
• Life cycle analysis
  • How much energy does it typically take to manufacture and install a heat pump?
  • How often (if ever) is it viable/worthwhile to repurpose an air conditioner in the winter, to help with heating?
    • Are there any "reversible" heat pumps that can work for both heating and cooling? (why)~ Manufacturing half as much stuff would certainly reduce life cycle emissions.
      
      ~ Use cases:
      - - ~ New construction
      - - ~ Any time someone has to replace their air conditioner anyway
      - - ~ Any time someone has to replace their heating system anyway, and doesn't already have an air conditoner but could use one

Refrigerant chemicals

Long-term problem ^{[RESEARCH needed]}

Because of how heat pumps work, they must contain a substance known as a refrigerant. Most refrigerants in use today^{[ELABORATION needed]} happen to be potent greenhouse gases. They aren't supposed to leak out into the atmosphere - but they sometimes do, if the heat pump gets old or is disposed of improperly.

This section is incomplete. It needs:

• Quantification
  • How much of climate change is due to refrigerants?
  • How much worse would it be if we all used heat pumps to heat our homes?
  • How does this compare to the status quo of heating (often natural gas)?
• Solutions
  • Are there any alternatives - refrigerants that aren't greenhouse gases? And are there tradeoffs? ^{[new page needed]}