Published Monday in the scientific journal Joule, the research found that heat pumps are two to three times more efficient than their oil and gas counterparts, specifically in temperatures ranging from 10 C to -20 C.

Oxford study proves heat pumps triumph over fossil fuels in the cold::Published Monday in the scientific journal Joule, the research found that heat pumps are two to three times more efficient than their oil and gas counterparts, specifically in temperatures ranging from 10 C to -20 C.

  • P03 Locke@lemmy.dbzer0.comEnglish
    12·
    1 year ago

    Even the study could have used some better clarification on geothermal HVACs, which is the direction we should all be heading towards:

    Ground-source heat pumps typically provide a very high level of efficiency, even during cold weather. The reason is that soil temperature does not change significantly between seasons, resulting in a higher—and more constan—COP. In addition, ground-source heat pumps do not need to expend energy on defrosting.

    This commentary focuses on the performance of air-source heat pumps in mild European winters with average January temperatures above −10°C. We refer to these heating conditions as “mild cold climates”, whereas those with average temperatures below −10°C in the coldest month are designated “extreme cold climates”.

    No, why?! Gimme the COP on geothermal. Google tells me it’s 3 to 5, but I would have liked a better source.

    Regardless, while I understand that we should spread out our solutions, I don’t understand why we’re not talking more about geothermal HVAC systems. Household solar is all the rage, but my gas company is still charging me $25 a month just to have the gas on, never mind the winter costs.

    If we’re talking about $5K a hole to dig for geothermal, that seems like a hell of a lot more cost-effective solution than either gas-based HVACs, or these air-based heat pumps. If it’s an area with only mild winters, you probably only need the one hole, which will last for 100 years at least. At most, we’re talking about 3-4 holes for a large house in Canada, and that’s going to pay for itself in 10-15 years.

    • alvvayson@lemmy.worldEnglish
      101·
      1 year ago

      Geothermal has advantages, but air source is getting so good that it’s really becoming a niche.

      Spending $5K on insulation or heat recovery ventilation will be more effective than spending it on a hole.

      I saw an awesome home refurbishment in Montreal, they just went all-in on insulation. The heating was just done with a 500W resistive heating coil, just for the coldest days. They didn’t even have a heat pump, except for the heat pump boiler. The heat recovery ventilation did the rest.

      • P03 Locke@lemmy.dbzer0.comEnglish
        2·
        1 year ago

        What if you already have good insulation? It’s already well-known that old houses have shit insulation, so of course it’s worth investing money into that if you already need it. But, even heating a new house can be expensive.

        • alvvayson@lemmy.worldEnglish
          1·
          1 year ago

          If you have good insulation then the weakest link is usually heat lost through ventilation, or an inefficient heating system.

          Ground source heat pumps have their place, but it’s really a niche. It is possible to cheaply heat a home without them.

      • DarthBueller@lemmy.worldEnglish
        1·
        1 year ago

        What is HRV? I thought it meant a ground loop heat exchanger. I’ve heard about it in the passivhaus model but don’t understand it.

        • alvvayson@lemmy.worldEnglish
          4·
          1 year ago

          Houses need fresh air and need to expel dirty air.

          The dirty air is warm, while the outside fresh air is cold. With heat recovery ventilation, the heat is transferred into the incoming air and the exhaust air becomes cold. This warms up the air in a very efficient manner.

          It can also be combined with a heat pump to extract even more heat out of the exhaust.