191–200 of 243 posts
Many heat pumps are installed with a large insulated buffer of water (for ex. 300L), which stores heat pretty well?
And homes that use underfloor heating in concrete can store heat pretty well too. Many people use that to heat up the home when energy is cheap and disable the heat pump when it is expensive.
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They don't work well with heat pumps. Heat pumps lose efficiency as the differential increases, so if you try to store heat in a tank, you quickly drop capacity and efficiency. Versus resistance, which is exactly as efficient at 0°C and 1000°C, and why those storage heaters used to make sense. (And storage is directly proportional to temperature differential above interior ambient)
Isn't it better to heat the water up to a point (let's say 40 or 50 degrees) and to heat it the rest of the way with resistance heating? >Versus resistance, which is exactly as efficient at 0°C and 1000°C It isn't. The difference is smaller than for a heatpump tho obviously.
This is partly due to a change in the refrigerant used.
> But storing the heat they produce has not been possible Many heat pumps are installed with a large insulated buffer of water (for ex. 300L), which stores heat pretty well? And homes that use underfloor heating in concrete can store heat pretty well too. Many people use that to heat up the home when energy is cheap and disable the heat pump when it is expensive.
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I ran the numbers for this a while ago. I live where we have proper winters (currently -22c). I wanted something simple just with solar thermal and water pumps (no heat pump). Sand batteries work at an industrial level, but for domestic use you want something simple so that means just water. A 100m3 (100,000 litres or 26,500 gallons) cylindrical water tank (approx 5x5m) buried and insulated with 50cm of XPS could pro…
Pedantic Pete here: • The centigrade is capitalized when used after a number. There is also a singular glyph for the entire degree-centigrade convention: ℃. • There are also superscript numerical characters to use with volumes, without having to use formatting: m³. UTF-8 is fun! As is automatic text replacement, once you have the appropriate triggers set up.
See page 758 of the Chapter 22 for the Unicode 9.0 standard:
Earlier quoted context omitted.
Isn't it better to heat the water up to a point (let's say 40 or 50 degrees) and to heat it the rest of the way with resistance heating? >Versus resistance, which is exactly as efficient at 0°C and 1000°C It isn't. The difference is smaller than for a heatpump tho obviously.
> It isn't. The difference is smaller than for a heatpump tho obviously. Where does the energy go then?
Earlier quoted context omitted.
Isn't it better to heat the water up to a point (let's say 40 or 50 degrees) and to heat it the rest of the way with resistance heating? >Versus resistance, which is exactly as efficient at 0°C and 1000°C It isn't. The difference is smaller than for a heatpump tho obviously.
Older heat pumps had max temperature limits and did often have resistance heaters to get that last push above 60C. Modern household heat pumps will reach 75C while staying above 100% efficient and can skip the resistance heater. This is partly due to a change in the refrigerant used.
Is this adequately maintained even as temperatures drop? I was recently considering getting a heatpump in addition to my gas installation but I assume I need to go for more than a bit better than resistance heating during winter for that investment to make sense.
They should've used lasagna. You could be in a tundra heating it over a fire and, as long as you get it sufficiently and consistently hot, it'll still burn your mouth 20minutes later.
I am still convinced the lava cheese insulator is there only to burn people's insides with boiling pineapple.
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It's funny how useful water is for power generation. There's heat storage as discussed here. Or you can store cold water in a reservoir as a giant battery, pumping it up high when you've got excess power, and letting it back down to generate hydroelectricity from it later. Or you can boil water to make steam that spins a turbine and use it to convert anything that can heat water (coal, oil, nuclear...) to electricity…
> It's funny how useful water is for power generation. It's gravity that does the generation. Water is convenient because it's weight per unit of volume is very high. Higher than most things we can get our hands on and it's also exceptionally safe. Since water isn't perfectly clean the main problem you face is corrosion. Which can take a great system and turn it into a nightmare of buried leaks and sudden problems. A…
They should've used lasagna. You could be in a tundra heating it over a fire and, as long as you get it sufficiently and consistently hot, it'll still burn your mouth 20minutes later.
Try Toast Hawaii. The weird mix of ham, pineapple and cheese the Germans make. I am still convinced the lava cheese insulator is there only to burn people's insides with boiling pineapple.
Although pineapple flavoured floor heating does sound delicious.
They should've used lasagna. You could be in a tundra heating it over a fire and, as long as you get it sufficiently and consistently hot, it'll still burn your mouth 20minutes later.