The Mighty Fan

In countries that have months of very hot weather, like Turkey where I live, it is important to have ways of being comfortable.  Diving into the sea or a pool does the trick but you can't do that all day, every day.  Night time can often be a major problem because being too hot can make it difficult to get to sleep and lack of sleep is bad for your health.  In my bedroom I have an air conditioner, which is a permanent fixture, and a portable fan.  I usually switch the air conditioner on about one hour before I intend going to bed, which cools the bedroom to a comfortable temperature, I then lie on the bed with no covering, switch off the air conditioner and switch on the portable fan, which is positioned to produce a cooling breeze over my body.  It usually doesn't take long before I am asleep and the fan is left to run all night.

The economics of my practice are interesting.  The air conditioner consumes about one kilowatt of electrical power, whereas the fan consumes about 40 watts.  Put another way, if the fan is left on all day and all night, it consumes less electricity than the air conditioner would consume in one hour of usage.  So for the period that I am asleep, the fan's consumption is less than the amount that would be consumed by the air conditioner in 20 minutes.  But of course, to compare a fan with an air conditioner is like comparing an apple with an orange.  The air conditioner does actually cool my bedroom and I can verify it by measuring the 'before and after' temperatures, which might, for example, indicate a drop from 30 degrees C to 20 degrees C.  On the other hand, the fan does NOT cool the bedroom.  It just makes me feel cooler.  It is the same effect when, in the winter, the weather forecaster talks about 'wind chill factor' and might say, for example, the daytime temperature will be four degrees C but because of the strong wind it will feel like minus two degrees C.  It is describing a perception that cannot be measured.  In my bedroom, the perception of cooling is created by the fan blowing a warm air layer from my body to be replaced by cooler air.  Also any moisture on my skin, like sweat, evaporates and creates an additional cooling effect.  But the effect cannot be measured, only predicted by various empirical formulae.

My bedtime cooling technique combines the old with the new.  The introduction of the fan predates the advent of electricity by many centuries, whereas air conditioning has only been possible since electricity was available.  But there is not just a difference in the maturity of the two technologies, there is also a fundamental difference in the technique.  In one case I am cooling the environment (my bedroom) in the other case I am cooling the body (me).  As I was mentally preparing this blog post, I mused about the problems people have working outside in high temperatures, for example hand-harvesting of crops in hot countries.  Unlike a bedroom, it is not possible to reduce the temperature of the outside environment, so for a worker to keep cool, some sort of fan technology might be the answer.  My wacky thoughts led me to the idea of a flat hat made from a thin solar panel, below which would be a fan, powered by solar energy, which directed a draught onto the worker's head!!  I doubt my creative thinking will ever see the light of day as a commercial product, indeed it might even have been thought of before - it's not difficult to reinvent the wheel!  Whatever, I hope those of you who are currently enjoying a long hot summer, are also managing to keep cool - happy days 😊