Evaporative cooling

I suddenly realized I hadn’t a clue about the science of this. Maybe a smarter member of the club will help me out.


But it is common knowledge.
Soak a T-shirt in water, put it on and ride. If air can get at that shirt, which it certainly can with any of the mesh jackets, you will feel a lot cooler until the shirt dries out. (Unless you are also dealing with high humidity, which we aren’t in the west.)
Problem is, when the temperature is high and humidity low, that T-shirt can dry out in a hurry and then you just have hot air blowing against your skin.
When I bought that mesh jacket last summer, it made a huge difference, but what allowed that mesh jacket to keep me cool for several hours at a stretch is a secret I now will reveal to you, my breathless audience.
The previous winter while shopping at my favourite thrift store I spied a thick, heavy, longsleeved, cotton pullover. While obviously designed for warmth, what caught my eye was the short zipper that allows the thick fabric to completely surround your neck. (Cooling your neck with those blood vessels to the brain is maybe even more important than cooling your torso.)
Since I immediately saw the possibilities for keeping cool rather than warm, I have never parted with two dollars more willingly!
I amputated most of the sleeves with a pair of scissors and think I will ask my wife to take off a bit more with her serger so they don’t fray.

I’m also considering cutting out the two pockets and having Gretchen “serger off” the bottom part maybe around belly button level.
The only problem with this garment is the room it takes in a saddlebag when you don’t need it.
Riding back from Boise in very hot and dry conditions, I would stop every two to three hours at a service station and visit the restroom. Holding the shirt by the hem, I’d let the top part plug up the sink as cold water filled to an appropriate depth. A slight wringing out so water wasn’t running down my butt, and I was off.
There certainly are commercial products that also absorb water, usually in crystals, take up less space when dry, and I should give mine another try. But they cost more. And do they cool your neck?
Staying cool in dry heat is most certainly a safety matter as well as a comfort matter. Incidentally, I also tried a wetted rag on top of my bald head the same trip. No cooling effect noticed, which maybe says something about my helmet ventilation.
Or, maybe, the thickness of my head.

Doug Sonju
if you have any comments send them to dougsonju@uniserve.com


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