arfbrookwood t1_iqqpaeb wrote
Reply to comment by dirk23wright in Shocked by gas bills, thrifty Dutch stockpile coal, wood for winter by clampie
Unless you live in a temperate climate heat pumps have to be really oversized (3x? If it gets really cold) to work in winter. And they take a lot of energy to work. It’s hard to pull heat out of cold dry air. For cold climates geothermal is a better way to go with current technology.
Edit: my comment is about air source heat pumps not ground source heat pumps which, yeah, work really well in cold climates!
Waste-Temperature626 t1_iqqqr9q wrote
> Unless you live in a temperate climate heat pumps have to be really oversized (3x? If it gets really cold) to work in winter.
I think people are stuck in the past when it comes to heat pumps honestly. People install even air based heat pumps up here in northern Sweden.
Yes, if it gets extremely cold you will probably be using some direct electric heating as well. But how often does it get to -15C in the Netherlands? The level where good modern heatpumps really start to struggle. For a typical Dutch winter heat pumps should be no problem what so ever from a tech standpoint.
dirk23wright t1_iqr85qc wrote
They should be buying mini-split systems, not wood burning stoves.
Direct_Rabbit_5389 t1_iqqqdlr wrote
It's not about the size of the pump, it's about the chemical technology used. Newer chemistries stay efficient to lower temperatures compared to older ones. Some are even efficient down below 0F.
(Conversely, a larger pump may not even help if you have a really old chemistry. Your pump would have to switch to backup resistive heat at the point where it's chemistry stops being efficient.)
hirsutesuit t1_iqr0ac2 wrote
Mine is still 100%+ efficient at -22F (-30C).
Direct_Rabbit_5389 t1_iqx55cf wrote
100% efficiency is a given -- resistive heating is 100% efficient due to the first law of thermodynamics. The important cutoff is when the heat pump becomes less than 400% efficient, or when the heat pump becomes less financially efficient than a gas furnace.
hirsutesuit t1_iqxpfjl wrote
No, it's not. The percentage would be different for everyone - and it could change everyday.
If you don't want to set things in fire in order to keep your house warm then anything more efficient than resistive heating is good.
dirk23wright t1_iqr7yhq wrote
Ground source heat pumps work great in northern climates. We have one in our house in Sweden, half the way up the country.
arfbrookwood t1_iqrhgn1 wrote
Ah we are talking about different things! A ground source heat pump is (I think) the same thing as a geothermal unit. There are also heat pumps that are NOT ground source but air source. This is what I was talking about.
dirk23wright t1_iqs33at wrote
I realize that.
These days, I believe they make various kinds of air heat pumps that work in cold temperatures. As others have said, they have air heat pumps that are still effective below 0 deg C.
In the Netherlands, there's no excuse to not have an air heat pump if you have a house. It doesn't get cold enough there to worry about efficiency loss. Why they insist on coal and wood is beyond me. Not only that, they aren't even buying good wood stoves, but regular ones. They're not buying the masonry types that have convoluted flues inside of them. Thermal efficiency is dramatically improved that way. Oh well. Just because they're European doesn't mean they're the sharpest tool in the shed.
I think the aversion to most air heat pumps is that they may hate blowing air. I know that Swedes generally don't like forced warm air heating. I assume the Dutch are similar, but I could be wrong.
Dewey_Cheatem t1_iqu3dw9 wrote
>I think the aversion to most air heat pumps is that they may hate blowing air. I know that Swedes generally don't like forced warm air heating. I assume the Dutch are similar, but I could be wrong.
It's mainly because construction companies cheapened out when they installed heatpumps in newly build houses. Undersized heatpumps hurt their reputation a lot.
And in existing houses you are looking at a 25k investment, plus a increase monthly electricity bill just for having more than 35A single phase.
dirk23wright t1_iqv9pja wrote
OK, that's unfortunate.
HyenaCheeseHeads t1_iqslohr wrote
Ground source = around 1m below the surface. Uses the average temperature of the subsurface layer (around 15C) as source of heat
Geothermal = around 100m+ depths. Uses geothermal energy from the earth's core (or hot springs, geysers, volcanic hot spots)
arfbrookwood t1_iqtanhd wrote
Air source is not below ground at all. That’s what I’m talking about.
[deleted] t1_iqqqdha wrote
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