Wouldn’t it be nifty to just drape a damp towel around your neck and have it effectively cool you down? Cooling towels require no electricity and can be re-used for a very long time. It sounds like a great idea — but how well do they actually work? Since The Place needed some love (in the form of manual labor), the cabin’s got no electricity, and the temps were going to be pushing three digits, it seemed like a great time to test one out.
What are cooling towels and how do they work?
Cooling towels are just cloth made of a fabric that wicks up quite a lot of water then helps it evaporate quickly. It takes energy to make water evaporate, so when the water leaves, heat energy is lost. On a hot day, about 44,000 J of heat energy is removed for every kg of water vaporized. (1)
To use a cooling towel, you get it really wet, wring it out, and lay it on you. It’s your body heat that is removed when the water evaporates. Couldn’t be easier.
Theory’s nice and all, but how much does it really help under the conditions a prepper might need it? A day of manual labor followed by a night with no AC at The Place seemed like a great time to do some experimenting. The towel I used was pretty standard and seemed to me about as efficient as other models I’ve used in the past. It was made of polyvinyl alcohol.
This cooling towel is a lot like the one I tested (which was a pretty run of the mill specimen).
Round 1: Cooling Towel vs. Mowing
First observation: These towels soak up a lot of water. The enclosed information claims it can soak up eight times its own weight. I wrung about half of that out, as water dripping off doesn’t remove nearly as much heat as water evaporating off.
This is the standard usage; the towel doesn’t slip much but doesn’t help that much either.
Second observation: The coolest place to put the towel is on the head like an Arabic head scarf (almost like desert dwellers know how to keep their cool), but it tends to slip off. A kerchief was needed to keep it in place; or go with the next best option of towel around the neck.
Heads have a lot of blood flow and sun exposure, so they are the best spot to cool.
Results: The towel helped, but not a lot. It felt cool on the skin, especially if I turned it frequently, but my overall experience was a pretty normal “Yep, still really hot pushing this mower up hills on a July afternoon.”
Round 2: Cooling Towel + Shade vs. 95 F day
Now it was time to sit, hydrate, and do some paperwork. Being still, I could fan the re-wetted towel out over neck and chest as I sat. I had good shade but only a tiny breeze. Interspersing periods of towel and no towel served as my crude control group.
Results: Minor edge to comfort with the towel. The evaporation of the towel seemed a little more efficient than my normal sweat evaporation, in other words.
Round 3: Cooling Towel to Improve Sleep
I’m ok without AC most of the time, but I admit to missing it on hot nights when I’m trying to go to sleep. I had hopes that the towel would improve the situation.
Third observation: The towel is not effective in a humid, still air environment. Re-wetted and draped over my legs for maximum skin exposure, the towel was actually slightly warmer than leaving my legs bare. That was right at sunset when there was no wind at all and the humidity was about 85%.
Fourth observation: A faint breeze makes the towels much more effective. Still too hot to sleep, I turned on a tiny little battery operated fan. Directing it over the towel made a big improvement in how cool I felt. After fifteen minutes my body temp was down to peaceful sleep levels and I needed neither towel nor fan.
How about some multimedia observations about the towels? Check out today’s podcast!
Was the cooling towel valuable?
Well, I’m not going to get more of them. I’d considered a supply for The Place, or for the in-town house without power. The level of cooling isn’t worth the opportunity cost in terms of storage space and hassle of use, to me. Here’s why:
- When we most need cooling in Missouri, it’s also humid, and also often still. Towels work poorly in these conditions. In a desert environment, I might make another choice, except:
- Cooling towels use a lot of water. At least it needn’t be potable water.
- A wet kerchief isn’t as efficient, but a kerchief is much more multipurpose.
They might be worth it in areas of lower humidity and/or more breeze, where water was not limiting. Small children or older people, whose temperature control tends to be poor, might benefit from them as blankets that would keep off sun and bugs while reducing the risk of overheating.
Check here for another post with some ideas on dealing with the heat.
Note: We have no financial interest in any product related to this post.
- From figure by Wilfried Cordes (WilfriedC) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons