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Oxford study proves heat pumps triumph over fossil fuels in the cold
(www.nationalobserver.com)
This is a most excellent place for technology news and articles.
This is the correct take for a conventional heat pump. However, there are relatively new geothermal heat pumps that can heat down to -30°C (-22°F) and are much more efficient.
https://www.cbc.ca/news/science/heat-pump-faq-1.6824634
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