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When is free cooling usefull?

  1. Apr 3, 2008 #1
    I'm trying to understand the concept of free cooling. I've found that this is the production of chilled water without the use of chillers, i.e. the use of cool air. But what I don't get is that if the temperature outside is low, isn't the need for cooling pretty much not there? I only see this to be useful for rooms which have a major internal heat production, like server rooms and such. Is this correct?
  2. jcsd
  3. Apr 3, 2008 #2


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    Science Advisor
    Gold Member

    The question of course is: How cool? Free cooling can be very useful. Do a bit of research (it takes very little) on a Sterling engine and you will know what I mean.
  4. Apr 3, 2008 #3
    Food refrigeration/freezing comes to mind. Rather silly to power a mechanical cooling system when the outside temperature is at or below the temperature of the refrigerator -- especially at a commercial scale.
  5. Apr 3, 2008 #4


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    This is entirely dependent on the space load since, as you pointed out, there is negative building envelope load in winter. Depending on the geometry of the building, it is quite common for large portions of an office building to have a relatively constant air conditioning load year-round. So proper load calculations and system conceptualization are the only ways to adequately answer the question.

    I'm currently dealing with a printing company who'se presses put off an enormous amount of heat (a megawatt or so). They also have significant exhaust and ventilation requirements, with much of the heat being in that exhaust. Figuring out whether this building needs heat or air conditioning in the winter is a significant problem. At the very least, you can't dump freezing cold air into a building, so the ventilation air needs to be heated somehow, either by heat recovery or mixing with room air.
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