Waste heat

Just mentioned this on IRC … and it occurs to me that it’s something the chattering classes don’t seem to have noticed. Perhaps if I blog about it, someone might.

Heat exchange is a lot more efficient than generating heat. So we should be using heat exchangers to harness far more of the heat that we generate. Some slight efforts have been made in this direction with combined heat and power, and with harnessing industrial heat for heating living or working space.

On the other hand, all the heat from my computer goes to waste. That on its own is fairly negligible, but in a big data centre that’s a lot of heat. Surely it’s time for server, rack, and other infrastructure-manufacturers to incorporate water-cooling pipes, so that their waste heat can be pumped into an exchange? The industry should adopt a standard size and placement for cooling pipes, so that components can slot together and just work.

With Nature’s heat, it’s the same story. Geothermal heat is popular in some of the most obvious places, like volcanic Iceland where it’s abundant and cheap. But heat exchange works even where there isn’t that extra natural heat: for example, in the UK, it can drastically reduce the energy required to heat a building. Not something you can easily retrofit, but it’s a shame to see it being ignored in new buildings.

One thing I would like to retrofit, if I had a garden, is a heat-exchange with a compost heap. That should be relatively easy, and compost generates lots of heat. Should work well for heating water, or feeding into a heating system.

Sounds like a great class of technology project for sixth-formers or college students with practical abilities. Any students or teachers listening? What are you doing?

Posted on February 12, 2008, in energy, environment. Bookmark the permalink. 7 Comments.

  1. Interesting idea about using waste heat from big data centres. I don’t know if it’s being done already, but the organisation I work for is looking to part-fund a new computer lab in Bristol. Don’t ask me what it’s for – it is to do with advanced modelling and requires an awful lot of computer power – but there is a serious proposal to harness the waste heat from the kit to contribute to the heating/cooling of the building. I hope this proposal goes ahead: All too often economics can kill off these rather good ideas for the more efficient use of “waste” energy.

  2. You want a water cooled datacenter? No problem – http://www.sun.com/products/sunmd/s20/ – just add power and cold water.

  3. Not sure about compost waste heat. In cold weather, when buildings need most heating, it seems tricky already to keep enough warmth in the compost to keep it working effectively. In hot weather, it might work, but I suspect modern solar to perform better then.

  4. When I worked at the Met Office the European Center for Medium Range Weather Forecasting had combined computing and heat, as the cooling for the Cray was plumbed into the heating.

    We had to open the windows for our spring training course, because the radiators were boiling hot on a beautiful and sunny spring day.

    So whilst I think it is a good idea, we probably ought to figure out how to reduce the heat production first, since we’ll still have to dump it when it is hot outside.

  5. Simon, so the heat generator was out of proportion to the consumer. Best solution: cut generation (why can’t I get an ARM-powered desktop box)? Next best: use it to heat something more than just your offices.

    In the domestic context, it’ll be useful just for hot water, even in summer.

  6. Good idea — though we still have a lot of low-hanging fruit left to pick in energy-intensive manufacturing plants that waste immense amounts of heat. Recycling this energy into power would do a lot toward cutting greenhouse pollution. I think energy recycling is one of those great untold stories that really should be getting more attention.

  1. Pingback: Paradigm shift: Eliminating waste heat « niq’s soapbox

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