[HN Gopher] Why Heat Pumps Are Immensely Important
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       Why Heat Pumps Are Immensely Important
        
       Author : herbstein
       Score  : 22 points
       Date   : 2022-03-26 19:20 UTC (3 hours ago)
        
 (HTM) web link (www.youtube.com)
 (TXT) w3m dump (www.youtube.com)
        
       | martythemaniak wrote:
       | Good video. I've been thinking about heat pumps a lot lately,
       | namely, is it possible to make geothermal ground loops cheap and
       | not disruptive? I wrote a bit about it here:
       | https://www.greennewdealio.com/heating/robot-mole/
       | 
       | Air source heat pumps really are great and it seems everyone in
       | mild climates should be moving towards them. In fact, what I'm
       | working on right now is trying to figure out the maximum ground
       | loop "budget", beyond which it would be cheaper to run
       | inefficient heat sources (COP of 1) for the small periods of time
       | where air sourced pumps no longer work.
        
         | deckiedan wrote:
         | Would it be possible to do multiple vertical shaft tubes,
         | straight down rather than a huge flat thing?
         | 
         | I feel like in 100 years time we'll have all these loopy pipe
         | arrays all over the place being a pain to clean up...
        
           | c22 wrote:
           | Yes, this is usually how it's done when a large field doesn't
           | happen to be available. Vertical boreholes are much more
           | expensive to make than shallow trenches, though.
        
         | sokoloff wrote:
         | I looked into air-to-water heat pumps (hard) as I'm planning to
         | replace my boiler this summer.
         | 
         | Even with large cast iron rads, I need 130degF water temp when
         | it's below about 25degF outside and the air-to-water heat pumps
         | struggle to hit 125degF output water temp there and fall even
         | lower when it gets colder.
        
           | chrislund wrote:
           | They aren't in all markets but there are heat pumps that use
           | CO2 as the refrigerant that can make quite-high output water
           | temps. They're often used for domestic hot water. I haven't
           | looked too deeply in to them but IIRC they have COPs around
           | 3-4. Sanden is one manufacturer, Mitsubishi and their Ecodan
           | line is another.
        
       | nimbix wrote:
       | If you pair a heat pump with good insulation, the effect can be
       | quite staggering. My parents moved into a new house 6 years ago
       | and their annual heating bill (for space and water) dropped from
       | ~2500EUR down to around 300EUR.
       | 
       | This is in an area where night-time winter temperatures hover in
       | the -5degC range, occasionally dropping to -10.
       | 
       | The old house was around 30 years old, with fairly thin
       | insulation (5 or 7cm was pretty standard back when it was built),
       | and had an oil burning furnace for heating.
        
       | Blackstone4 wrote:
       | I've looked at ground heat pumps before (not air pumps). However
       | they are a huge capital outlay of PS10k-PS19k ($13k-$26k).
       | 
       | Both air and ground heat pumps work best for buildings with
       | underfloor heating. Floors cover a much bigger area than
       | radiators so they don't need to get as hot to provide the same
       | amount of heat.
       | 
       | We're in a 70 year old building so that doesn't help.
       | 
       | The savings are minimal maybe PS30-PS60 a year before the recent
       | gas price increases. You can get grants of PS2k per annum for 7
       | years so you will get money back. However they don't really save
       | any money unless you think gas prices will remain high. Outside
       | of that you do it to be green.
       | 
       | https://www.which.co.uk/reviews/ground-and-air-source-heat-p...
        
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       (page generated 2022-03-26 23:01 UTC)