Heat pump: Difference between revisions
(Created page with "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. Heat pumps are '''more energy-efficient''' than electric heaters.{{qn}} ==Research needed for this page== * ''How much'' more energy-efficient can a heat pump be? ** How does this depend on outdoor temperature? * How much energy does it typically take to ''manufacture and install'' a heat pump? *...") |
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An electric heat pump is one way to [[heating|heat a building]]. It works a lot like [[air conditioning]] but in reverse: The hot air goes indoors; the cold air goes outdoors. | An electric '''heat pump''' is one way to [[heating|heat a building]]. It works a lot like [[air conditioning]] but in reverse: The hot air goes indoors; the cold air goes outdoors. | ||
{{considerations}} __NOTOC__ | |||
== | ==Energy efficiency== | ||
{{sum|Only in some cases}} | |||
* | |||
* How much energy does it typically take to ''manufacture and install'' a heat pump? | Heat pumps can be more energy-efficient than electric heaters. But this efficiency gain disappears when the outdoor temperature is cold enough.{{qn}} | ||
* | |||
Worse: When electricity is generated by [[fossil fuels]], electric heating has up to 3 times the carbon emissions of just burning the fossil fuels directly in a [[natural gas]] furnace {{p2|[see why]|Most coal or natural gas power plants are only 33% efficient. They work by boiling water and driving a turbine.{{minor|Exception: Newer "combined cycle" natural gas power plants can get up to 60% efficient. But for heating homes, that's still less efficient than burning the natural gas at home.<br /><br />Also note: Electricity has losses in transmission too (power lines) - typically about 5%.}} }}. Heat pumps are almost never efficient enough to make up for this. | |||
Maybe it's worth getting a heat pump if you live in an area where winters are moderate and electricity is generated mostly by renewables or nuclear.<sup>[WORLD MAP needed]</sup> | |||
<tab name="Research needed for this section"> | |||
{{minor|Can be a case study or generalized statistics}} | |||
* Need graph: Heat pump efficiency vs 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? {{p2|(why)|~ Manufacturing half as much stuff would certainly reduce life cycle emissions.<br /><br />~ Use cases:<br />- - ~ New construction<br />- - ~ Any time someone has to replace their air conditioner anyway<br />- - ~ Any time someone has to replace their heating system anyway, and doesn't already have an air conditoner but could use one}} | |||
</tab> | |||
==Refrigerant chemicals== | |||
{{sum|{{qn}} }} | |||
Because of how heat pumps work,<!-- TODO: add a section about how they work --> they must contain a substance known as a ''refrigerant''. Most refrigerants in use today{{en}} 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? {{npn}} | |||
==See also== | |||
* [[Heating]] | |||
* [[Map of electricity by source]] | |||
<!-- TALK: rename this page to "heating with heat pumps"? --> |
Latest revision as of 02:40, 30 August 2023
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 efficiency
Heat pumps can be more energy-efficient than electric heaters. But this efficiency gain disappears when the outdoor temperature is cold enough.[QUANTIFICATION needed]
Worse: When electricity is generated by fossil fuels, electric heating has up to 3 times the carbon emissions of just burning the fossil fuels directly in a natural gas furnace [see why]Most coal or natural gas power plants are only 33% efficient. They work by boiling water and driving a turbine.Exception: Newer "combined cycle" natural gas power plants can get up to 60% efficient. But for heating homes, that's still less efficient than burning the natural gas at home.
Also note: Electricity has losses in transmission too (power lines) - typically about 5%. . Heat pumps are almost never efficient enough to make up for this.
Maybe it's worth getting a heat pump if you live in an area where winters are moderate and electricity is generated mostly by renewables or nuclear.[WORLD MAP needed]
Can be a case study or generalized statistics
- Need graph: Heat pump efficiency vs 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
- 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.
Refrigerant chemicals
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]
See also