Are these a thing?
Lets say I have a device that generates around 200-500watts of heat at anywhere from 40-80C (PC mining bitcoin for example). I want to capture as much of that heat as possible in another system (pre-hot water tank for example).
How can that be done?
Drop the PC in a fish tank full of oil (googles it up). Put some coiled copper pipe in the oil. Pump water through the copper pipe. Profit.
Water or fish tank PC aren't heat pumps though. If a heat source is 50C and the water is 50C, there is no heat transfer.
A peltier would work, but they are horribly inefficient. I was thinking more like vapor compression cycle but on a tiny scale.
You missed the bit about the copper pipe to suck the heat out. Duh.
WHAt about a dorm fridge.
Dr. Hess said:You missed the bit about the copper pipe to suck the heat out. Duh.
No, I didn't. Unless that's part of a heat pump system, it has the same limitations I mentioned above.
Fueled by Caffeine said:WHAt about a dorm fridge.
Actually, a full size fridge might be around the right size.
I don't really know hot wo size a heat pump, would need to brush up on my thermo. Could be a fun project just for the hell of it.
Take the max wattage of your system. So 600 watts just for a bit of extra room. Then the amount of extra energy used to move the heat is roughly a quarter. So now we are at 750 watts. Since you want the computer to be above ambient temp then the loses through the cabinet of the fridge is actually helping so we don't even need to consider those loses.
Then I would buy a mini fridge with at least 1000 watts. Just for extra breathing room and if you have to open the door and lose some cooling from that.
window airconditioner of a smaller size, would probably work as well.
What do you need/want to exchange the heat to? There are a lot of ways to do this, but sometimes the level of efficiency varies depending on the scale of the system as well as the requirements of the entire system. You only mention have of what you want to do.
A lot of the small cooling appliances (window a/c, small refrigerators, etc) use R134a refrigerant. If you have a vacuum pump and r134a gauges for working on car a/c, you can use them to work on those appliances with the right adapters and modifications to the appliances to add service ports. The goal would be you can then reconfigure the refrigerant system to cool things in different formats.
Here's a how-to on adding a service port: http://www.hvachowto.com/2016/07/02/how-to-install-a-service-port-on-sealed-system-window-air-conditioner/
Ross, if it takes 1/4 the energy to move the heat, I would only need 150 watts to move 600 watts of heat, no? This seems way too general as its going to depend on temperatures we are working with.
Anyway, fridges (full or mini) are nowhere near 1000 watts. Normal load for a full size fridge is around 100-200 watts.
Ian F said:What do you need/want to exchange the heat to? There are a lot of ways to do this, but sometimes the level of efficiency varies depending on the scale of the system as well as the requirements of the entire system. You only mention have of what you want to do.
A 40 gallon hot water tank.
So I want to take 200-500 watts of PC energy and dump as much as I can into a 40 gallon hot water tank that will range from 10C (freshly filled with incoming water) to say 100C (or wherever efficiency falls off and there is no point in doing it anymore). In this hypothetical scenario the PC and the hot water tank can be located right next to one another physically.
In reply to ProDarwin :
DOH! You are right. I was stuck in a different mental gear regarding heat pumps!
You'll need to log in to post.
