Air cooled data centres are hot!

Air cooling in the automotive world has practically disappeared, with the last major hold-out - Porsche - having moved to water-cooling its cars' engines more than 10 years ago in order to reduce emissions. Data centres are moving in the opposite direction but for precisely the same reason: they're big carbon emitters, with …

[Nigel 11]

Heat pumps

It should not be difficult to design an air-conditioning system so that the "waste" heat is pumped to somewhere useful. For example, into the building's central heating/ hot water system, so that in winter the boiler has to burn less fuel, and in summer the hot water is "free". (You might still have to dump some unwanted heat on the outside). Better still, in summer, run a ground-source renewable heating system backwards - heat up a chunk of earth or rock with the "waste" heat, and then pump that stored heat back inside when winter arrives.

Of course this is easier still if you design the server centre together with an appropriate quantity of nearby residential accomodation as your "heatsink", rather than as a standalone unit in the middle of a commercial centre.

It's called joined-up thinking, and there's far too little of it going on.

[Ammaross Danan]

Hot Water

The difficulty you run into with the "hot water" idea is that you can only heat the water up to the temperature of the hot air exhaust (perhaps ~48*C or so if you're running dense), which is still about 12*C colder than the energy-conscious "low" setting of a hot water boiler. Heating the water more than that would require energy to push the heat into already-warmer water.

Now, they already heat the building the data centre is in, but the idea of heating a surrounding residential zone is kind of interesting. Granted, they can't do so during the months when most would prefer AC over heating....and they'd have to figure in the cases of "what if most of the homes are already 'hot enough' and turn off their heat at the same time?" It starts adding complexity when you can't for-sure dump your heat. Ground pipes have the same general problem as the water heating method: once the immediate surrounding ground is saturated, the cooling effects become less efficient, and you're forced to dump heat elsewhere. Unfortunately for your "reclaim it in winter" idea, the heat would have long since dissipated by the time the season changes.

Your "joined-up thinking" would work, if your view of thermodynamics was actually accurate...

[Bob H]

Pre-heating

One core fact that people tend to ignore is that just because there isn't sufficient energy to heat the water to a usable temperature doesn't mean that the system isn't useful. Just by providing a store of warm water you can reduce the heat (fuel) needed to raise it to a reasonable temperature. I am not sure if a municipality would want to run a "warm water" source but others have commented that swimming pools have been heated by data centres so I suppose someone does!

In addition to municipal water, one small advantage may be in using the cooling water to power a Sterling Engine which can be used to provide auxiliary power for pumping, thus improving the energy usage of the system. Put the Sterling Engine under the cooling pool so that it uses the differential between the deep earth and the warm water for constant running. Or perhaps adjacent in order to have more energy when it is environmentally "more hot" or "more cool".

No one solution is going to save the unborn differently-able baby whales but with good design and multiple approaches we can make the most of what we produce.

[Anonymous Coward]

You will find...

... That with the right methodology in place, you can get 48C temps to make a huge difference. Proof is the heat pump at Castle Howard, which works off just 10C temperature differential and which has managed to reduce the heating bill for the stately home by 90%.

Make some sums and see how much hot water can be produced by a data centre daily and you'll probably find that a local leisure centre can use that amount of water to reduce their bills too.

[Dagg]

Infrastructure costs

This might be slightly useful where the local residential accommodation needs heating all year around. However this is never the case, so this would only be useful for about 3 to 6 months of the year in places that have a summer and winter rather than a dry and wet season.

To provide a set of duplicate heating cooling infrastructure to allow the data centre to heat houses during the winter and pump heat somewhere else during the summer will cost. The same summer cooling infrastructure would work all year around so why would they bother trying to heat houses with NO cost saving and a lot of extra cost building the house heating infrastructure.

There is not a lot of use for low grade heat of the type produced by a data centre and any attempt to use it would increase the initial infrastructure build costs for very little if any return.

[Gianni Straniero]

HVDC FTW

How much of that heat is generated by the AC > DC > AC > DC conversion typical in a UPS-backed data centre?

[Ammaross Danan]

Ideas

They've already thought of that. Look up DC Bus Bars or the like. They have a single large UPS to high-volt bus bar transformer, and it's from that bus bar that a step-down transformer powers each server.

[Bob H]

Open Compute

That is why the new Facebook facility doesn't use 110V AC for powering servers but the interesting figure of 277V to reduced transformer losses. And why they have a commodity UPS per group of racks which outputs 48V DC to the server.

Paris, because she likes efficiency of clothing. All hail the mighty facebook!

[Marcus Aurelius]

Simples

Build your data centre in Iceland - they need the revenue!

[defiler]

And they've got freezers

Just stuff your blade servers amongst the fish fingers and frozen pizzas, and hope Kerry Katona keeps her mitts away from the power switch.

[GCom]

Sub 1 PUE

With the arrival of more efficient heat exchangers, modular design and super critical turbines im expecting to see a design for a sub 1 PUE data centre some time soon

Watch this space

[Ammaross Danan]

So...

You're expecting a data centre that requires less power than it takes to run the data centre? A PUE of 1 means zero energy is used in cooling (the bottom co-efficient is the power required by the computing equipment mind you). So, unless the servers are generating their own power from an alternate universe (see Stargate for precedent), then you won't see <1 PUE.

[Bob H]

I'll get my flux capacitor...

That is all....

[Brad 8]

And Ammaross took it hook line and sinker.

The sub 1.0 PUE data centre would be driven by a perpetual motion drive.

[GCom]

Take the next logical step

A PUE of < 1 purely means reusing at least some of the energy exhausted as heat to power the servers a second time

While i admit this has been demonstrated to date the fundamental technology underpinnings have advanced rapidly in recent years to enable it to take place

[Knoydart]

Re: Heat Pumps

There is at least 1 new data centre in London already designed to provide heating and cooling to a property next door so your on to it.

That or you do an IBM and heat swimming pools or in Finland, they join data centers to the local district hot water system

Flames for heating....

[Marcus Aurelius]

Crematoria

...are also good heat sources.

http://www.telegraph.co.uk/news/newstopics/howaboutthat/8279648/Crematorium-heats-swimming-pool.html