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Cooling the human body with fans.

  1. Dec 2, 2009 #1

    I'm a cyclist who has just got some rollers, which allow me to ride inside without going anywhere - essential if I want to ride on harsh winter days.

    The problem is, without the cooling airflow normally experienced when out on the road, heat exhaustion makes long periods of indoor training unbearable!

    Most people get the biggest fan they can afford, but after testing a few out, i've realised that getting just a little bit more power from a fan can cost a LOT of money. For example, I can get 8 standard desk fans for the price of one which is twice as powerful as those and for the price of 5 of them, I can get one which is about 50% more powerful.

    My questions:
    If I buy 3 or 4 of the cheap, standard desktop fans, would they be more effective at cooling my body than the larger one, if used all at once, despite being less powerful individually?

    If so - would using multiple fans be more effective if I placed them together, or pointing at different parts of my body from different angles? Would placing them in any arrangement other than a one-directional setup cause any kind of significant cancellations in the airflow, reducing the effectiveness of them?

    Could multiple weak fans actually be more powerful than one big fan? Or would you just get the maximum amount of power that the fans could individually produce, but just more airflow over a larger volume of space?

    What's the best cooling strategy here? Obviously, i'll have the fan(s) as close to me as possible, but is there anything I can do to improve the cooling? For instance, would setting up near a wall/cooling help/hinder the airflow/cooling?

  2. jcsd
  3. Dec 2, 2009 #2


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    One of the easiest things to do is wet a headband or even your shirt. The fan breeze plus the evaporative cooling from the water work very well. I know that for a fact since I used this scheme in desert conditions.

    As far as the fans go, really you need to be able to look at the flow numbers from each. It would, most likely, be more economical to get multiple, cheap fans and be mindful of placement. I have a hunch (because I have never done this kind of price comparison) that one large flow capacity fan will be much more expensive.
  4. Dec 2, 2009 #3
    Volume has a linear effect on power consumption while velocity has a cubic effect. To get the most cooling with the least power consumption you want high volume, low velocity. That means getting a nice wide fan or multiple fans stacked together - ideally as wide and high as yourself plus the bike - and setting them on a low speed. Or ideally starting with energy efficient fans designed for low speed.

    Also agreed that any water on your body will aid the cooling.
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