4 ms·

In some buildings, installing a heat pump is "only" a matter of swapping out one large appliance with another (since you're able to reuse the ducts, etc.) but t

by seoaeu 5y ago

In some buildings, installing a heat pump is "only" a matter of swapping out one large appliance with another (since you're able to reuse the ducts, etc.) but that's still widely expensive and logistically complicated to do on scale of a country.

Tomte 5y ago
In America. Heating/cooling ducts and "outdoor units" that could be swapped are very rare in Germany. We use mostly radiators, and in newer buildings in-floor heating. Both are based on warm water pipes.
- jaclaz 5y ago
  Well, at least for single apartments/houses (cannot really say for huge multi-apartments buildings) heat pumps that exchange with water exist and are very well suited to in-floor heating (but not suitable for radiators). The generic issue with heat pumps AFAIK is that they have only a relatively small range of temperatures (outside) in which they are actually efficient, in the sense that (with old prices of energy) they are competitive with gas in costs, I believe that Germany is a bit too cold.
  - Tomte 5y ago
    Sure they exist. But it's more than just "swap one unit with another" which was the claim above. Heat pumps are actually pretty efficient, down to low temperatures. Have a look at https://www.youtube.com/playlist?list=PLv0jwu7G_DFVIot1ubOZdR-KC-LFdOVqi https://www.youtube.com/playlist?list=PLv0jwu7G_DFVIot1ubOZd... where Alec discusses that. Around Chicago you can expect to have only a few days in winter where the COP is bad: https://www.youtube.com/watch?v=MFEHFsO-XSI&list=PLv0jwu7G_DFVIot1ubOZdR-KC-LFdOVqi&index=2 https://www.youtube.com/watch?v=MFEHFsO-XSI&list=PLv0jwu7G_D...
    - jaclaz 5y ago
      Not really, of course it depends, but IF the actual heat diffusion system is compatible (fan-coils or under floor) it can be pretty much "swap one unit with another", at least for single units. Still, to give you a single datapoint, I just replaced on a unit a small gas heater with a heat pump and it was really a "swap one unit with the other", still a few issues came out: 1) the cost of the unit, even considering that it doubles as air conditioning/refreshing was only affordable because of some government subsidies (think of 6-7,000 Euro compared to 2,000 Euro for a gas heater and 2,500 Euro for a more traditional conditioning unit) 2) for some reasons, the heat pump is much slower in heating, the net result (in my specific case) is that the unit needs to be kept slightly heated on weekends (it is a small shop that closes saturday and sunday) otherwise when it opens on monday it will take forever to reach a suitable temperature. Besides, from an infrastructure point of view, if many people change from gas to electrical (though gas powered heat pumps do exist, BTW) the local increase of consumption from the grid needs to be taken into account.
- nullc 5y ago
  You can use heat pumps to heat water... in fact, it's a very good form of energy storage for off-grid homes in cold climates: You put in a 100 gallon water tank, use a heat pump water heater to bring it up to 150deg F when the sun is shining. You use fail safe mixing valves to provide hot water for the taps/showers (which greatly increases the effective size of the hot tank), and the hot water can be used more directly for heating. Retrofits can be hard though, since the water loop may be designed for a rather high temp... though there are some heatpumps that get to rather high temps.

by seoaeu 5y ago

Tomte 5y ago

In America. Heating/cooling ducts and "outdoor units" that could be swapped are very rare in Germany. We use mostly radiators, and in newer buildings in-floor heating. Both are based on warm water pipes.

jaclaz 5y ago
Well, at least for single apartments/houses (cannot really say for huge multi-apartments buildings) heat pumps that exchange with water exist and are very well suited to in-floor heating (but not suitable for radiators). The generic issue with heat pumps AFAIK is that they have only a relatively small range of temperatures (outside) in which they are actually efficient, in the sense that (with old prices of energy) they are competitive with gas in costs, I believe that Germany is a bit too cold.
- Tomte 5y ago
  Sure they exist. But it's more than just "swap one unit with another" which was the claim above. Heat pumps are actually pretty efficient, down to low temperatures. Have a look at https://www.youtube.com/playlist?list=PLv0jwu7G_DFVIot1ubOZdR-KC-LFdOVqi https://www.youtube.com/playlist?list=PLv0jwu7G_DFVIot1ubOZd... where Alec discusses that. Around Chicago you can expect to have only a few days in winter where the COP is bad: https://www.youtube.com/watch?v=MFEHFsO-XSI&list=PLv0jwu7G_DFVIot1ubOZdR-KC-LFdOVqi&index=2 https://www.youtube.com/watch?v=MFEHFsO-XSI&list=PLv0jwu7G_D...
  - jaclaz 5y ago
    Not really, of course it depends, but IF the actual heat diffusion system is compatible (fan-coils or under floor) it can be pretty much "swap one unit with another", at least for single units. Still, to give you a single datapoint, I just replaced on a unit a small gas heater with a heat pump and it was really a "swap one unit with the other", still a few issues came out: 1) the cost of the unit, even considering that it doubles as air conditioning/refreshing was only affordable because of some government subsidies (think of 6-7,000 Euro compared to 2,000 Euro for a gas heater and 2,500 Euro for a more traditional conditioning unit) 2) for some reasons, the heat pump is much slower in heating, the net result (in my specific case) is that the unit needs to be kept slightly heated on weekends (it is a small shop that closes saturday and sunday) otherwise when it opens on monday it will take forever to reach a suitable temperature. Besides, from an infrastructure point of view, if many people change from gas to electrical (though gas powered heat pumps do exist, BTW) the local increase of consumption from the grid needs to be taken into account.
nullc 5y ago
You can use heat pumps to heat water... in fact, it's a very good form of energy storage for off-grid homes in cold climates: You put in a 100 gallon water tank, use a heat pump water heater to bring it up to 150deg F when the sun is shining. You use fail safe mixing valves to provide hot water for the taps/showers (which greatly increases the effective size of the hot tank), and the hot water can be used more directly for heating. Retrofits can be hard though, since the water loop may be designed for a rather high temp... though there are some heatpumps that get to rather high temps.