4 ms·

I think this is a nice summary. As a point for water cooling, it's easier to use the generated heat; it can for instance be used to heat nearby buildings. With

I think this is a nice summary. As a point for water cooling, it's easier to use the generated heat; it can for instance be used to heat nearby buildings. With air cooling this is much more difficult. I think watercooling will become dominant in new data centers as environmental laws sets stricter requirements for heat waste.

bo0tzz 4y ago
> With air cooling this is much more difficult To my understanding, DCs use air conditioning systems for cooling. These are already heat pumps - why would it be more difficult to just pump that heat into district heating instead of outside air?
- 4str0n0mer 4y ago
  Because the temperature spread a given heat pump uses isn't really suitable for district heating, your output water would only be in the 50 to 60°C range at most, too low for typical district heating systems. One can get around that with multi-stage heat pumps or different coolants, but both are expensive investments typically not viable for existing systems.
  - nine_k 4y ago
    If it's not enough for district heating because of the distance and heat losses, it could be enough for a greenhouse right next to a DC. Economically the greenhouse would have a distinct advantage of using free heat, and already having enough electricity wired nearby. This, of course, only makes sense during cold seasons, or somewhere like Alaska or Sweden. During hot months, 40-50°C of heat seem completely useless. Maybe next to a sea such waste heat could help evaporatively desalinate seawater, while cooling back to reusable temperatures.
4str0n0mer 4y ago
Yes, heat reuse is easier with water cooling since the losses are smaller, but even air cooling will produce warm water in the end. There will be coming regulations requiring a certain amount of heat reuse, but in a first step, this probably won't force direct water cooling. For those regulations, there is also the important aspect of free cooling, i.e just using outside air as a medium or using an air-air heat exchanger like a Tokyo Wheel. Mandated heat reuse (without appropriate exceptions) would make those illegal, however in certain situations those are the best (environmentally and financially) methods of cooling. E.g. in a moderately hot summer you can use 20-30°C outside air without a problem, but if you would mandate heat reuse at that time, you would have lots and lots of excess heat on your hands with nobody buying it. So while some regulation will be coming, I hope and think that it wouldn't really issue a strict mandate to reuse heat and allow free air cooling, which would exclude direct water cooling.

bo0tzz 4y ago

> With air cooling this is much more difficult To my understanding, DCs use air conditioning systems for cooling. These are already heat pumps - why would it be more difficult to just pump that heat into district heating instead of outside air?

4str0n0mer 4y ago
Because the temperature spread a given heat pump uses isn't really suitable for district heating, your output water would only be in the 50 to 60°C range at most, too low for typical district heating systems. One can get around that with multi-stage heat pumps or different coolants, but both are expensive investments typically not viable for existing systems.
- nine_k 4y ago
  If it's not enough for district heating because of the distance and heat losses, it could be enough for a greenhouse right next to a DC. Economically the greenhouse would have a distinct advantage of using free heat, and already having enough electricity wired nearby. This, of course, only makes sense during cold seasons, or somewhere like Alaska or Sweden. During hot months, 40-50°C of heat seem completely useless. Maybe next to a sea such waste heat could help evaporatively desalinate seawater, while cooling back to reusable temperatures.

4str0n0mer 4y ago

Yes, heat reuse is easier with water cooling since the losses are smaller, but even air cooling will produce warm water in the end. There will be coming regulations requiring a certain amount of heat reuse, but in a first step, this probably won't force direct water cooling. For those regulations, there is also the important aspect of free cooling, i.e just using outside air as a medium or using an air-air heat exchanger like a Tokyo Wheel. Mandated heat reuse (without appropriate exceptions) would make those illegal, however in certain situations those are the best (environmentally and financially) methods of cooling. E.g. in a moderately hot summer you can use 20-30°C outside air without a problem, but if you would mandate heat reuse at that time, you would have lots and lots of excess heat on your hands with nobody buying it. So while some regulation will be coming, I hope and think that it wouldn't really issue a strict mandate to reuse heat and allow free air cooling, which would exclude direct water cooling.