Evaporation Explained
posted by citizen.K on Sunday, July 27th, 2008 / 
Print & Hang in the Barn
Recently, a woman with many, MANY years of horse experience told me I shouldn’t turn my horse outside after a bath because “water is an insulator and will keep them hot.”
I never thought I would question my own logic when it came to the cooling effects of evaporation, but the ridiculousness of the statement convinced me I was suffering from hearing dyslexia.
Me: I’m sorry, what was that?
Woman: I can’t believe you do that…you know water is an insulator.
For the better part of two decades, this woman has been considered a horse “professional”.
“You know those [post ride baths] are why he’s loosing weight.”
I was dumbfounded. Had this woman never played in the lawn sprinkler as a young child? Had this woman never taken part in a rogue, neighborhood fire hydrant opening? Had she never taken a dip in a pool on a 90 degree Fahrenheit day?
Was I really going to have to explain the properties of evaporation to a woman who in the past has been paid to train and care for horses?
Answer: No. I say this a lot, and it’s especially true for the horse world, but you can’t reason with crazy people. And don’t get me wrong, I’ve heard a lot of crazy things from crazy horse people, but this was just stupid.
I stood there dumbfounded. I must have looked like a moron. After a ride and cool down in the heat of summer, I’ve never deviated from a well-deserved bath, the sweat scrape, a nice stall lunch, and turnout back to the pasture. Who was this horse woman and what planet did she come from?
She continued.
Woman: You know the water is why he’s loosing weight.
!!!
Yes, weight loss has been a problem recently; factors I had seen contributing were the new terrible hay, the heavy workload, and the fact the barn managers were having 8 year old kids campers feeding breakfast and dinner. In more ways than one, a barn move has been a few months overdue.
And now that super-triple-crazies were stalking my wash stall practices, I began thinking my problems at this barn had multiplied to the level only full-time security guards could handle.
Where has common sense gone!?
Me: Actually, evaporation works to cool the body.”
She argued with me.
As my gaze-of-opposite-amazement grew, I started making a b-line for the car. Safety. I needed safety. I knew I needed to leave, quickly. There was nothing for me to do here.
I tried to give her the benefit of the doubt. I tried to fathom she had read, somewhere, that water was an insulator, PERIOD. But even after that leap, how could one fail to understand the capacity of water insulation and how it relates to a horse being wet?
Factoring in semantics, water IS an insulator of temperature, meaning, water requires high amounts of heat energy to raise said temperature.
However, water being seen as an insulator is a whole different story. How does one not understand the cooling effects of water droplets in relation to heat transfer and the state change from liquid to gas? I assumed this woman must never shower, ever. She must have never seen a coach assailed by his winning team with a bucket of cooled sports drink. She must of never seen a dog shiver in the rain. She must have never visited a desert.
She must not have sweat glands.
One thing is for sure; she must be stopped. She must be stopped from owning or caring for animals. She must be stopped, at least, from ever talking to me again.
Needless to say, I left the barn, completely beside myself.
To anyone else confused about the cooling powers of water, lets talk 3rd grade science.
Water requires high energy/heat for evaporation, and evaporation is inversely related to cooling of ambient temperature. When ambient temperature approaches body temperature, the rate of heat loss slows to the point that very little heat can be removed from the body by any of these means. That’s when evaporation becomes important. Ergo wet horse.
One way to cool a horse in a hurry is to soak a horse with cold water. First, the cold water comes in direct contact with the skin, heat is added to the water by conduction (from body temperature) accomplishing some cooling; a temperature difference of, say 95°F skin temperature relative to 55°F water temperature being the driving force. But more importantly, some water will be evaporated from the skin surface, removing over 1000 BTUs for every pound of water evaporated. Increasing air movement with a fan or wind speeds heat loss from the combination of evaporation and convection.
So, we now understand evaporation does happen when a horse is wet AND evaporation is a cooling mechanism.
Phew – I thought I was totally loosing my mind.
9 Responses to “Evaporation Explained”
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July 28th, 2008 at 12:04 am
Oh man, I feel for ya. YOU CAN’T REASON WITH CRAZY PEOPLE. It’s the law of the universe I think. I think where you went wrong was when you said “Actually, evaporation works to cool the body.” BIG mistake. You’re better off to just play deaf. Or say “O.K. Thanks.” in a half-sarcastic/half-noncommittal tone. And then promptly continue along your way. Sounds like it IS time for a barn move. Especially if you’re paying a lot of money to be where you’re at. I suggest http://www.polocenter.com I’ve found a lot of barns through that website.
July 28th, 2008 at 1:48 pm
WTH? Yeah, I’ve had people tell me a lot of stupid things like that before… It called science. Its usually right when its been accepted for uh…centuries.
*shakes head* Those stupid horses that LIKE the baths after hot days…STUPID!
July 30th, 2008 at 8:08 pm
Well, this just throws me for a loop. If evaporation isn’t a cooling mechanism, why do we and our horses sweat when we’re HOT? I mean, if this lady is correct, we should sweat when we’re COLD, right?
Oh, I’m SO confused…..
August 3rd, 2008 at 9:20 pm
Wow, what is that horse person on? Where would you get that information? I’m confused too!
Sweating is a cooling mechanism through evaporation, therefore a wet horse would get cooler.
The horse world is full of people who know nothing, but have the ability to take the knowledge of nothing and really build a career out of it!
Get outta that barn!
March 21st, 2009 at 9:43 pm
The only POSSIBLE plausible thing that MIGHT have been running through her head is when you soak a hot horse with cold water and that cold water heats up. Then IF YOU DON’T SCRAPE THEM OR LET THEM ROLL, they the water DOES insulate the skin from evaporation. This is why you see TEAMS of people sloshing water on event horses and scraping it off of them as fast as they can.
But if you are scraping the horse and/or he is past that hysterical 35-mile-and-hour gallop in 90-degree-weather overheated hot, you are just making things up.
I evented an AQHA mare who was cutting bloodlines and was all fast-twitch fibers and just built like a tank. She took a long time to cool off after a gallop because it was a long way from inside her muscles to the skin and outside world. And I just kept walking and sloshing and scraping. She never had heat-related health problems, just took her a while longer than a TB to get her temp down after a good cross-country phase.
Also, some horses don’t like thier faces hosed (and some love it). I’ve heard it’s bad to get water inside a horse’s ear canal, but that has NOTHING to do with cooling them off or the properties of water…
Wow…
March 23rd, 2009 at 1:15 pm
i am a BSc Equine Science student at aber univercity and i can agree with the “crazy woman” soaking a horse after excercise may give tempory relief from the heat but you forget that the horse has fur unlike us that traps the water as it is heated by the body there fore keeping the horse warm far longer than if the sweat had been allowed to cool. have you never felt your horse after one of these ‘cooling’ baths and felt that he is still hot.
evaporation is the least effective way of cooling and rasiation and convection help the horse cool better hell even nummnas and bandages help better than evaporation as heat is transfered to them and they canbe taken away faster than water evaporates especially if the air is humid and water is less likly to evaporate anyway.
the best thing to do to cool your horse better is to wate till the sweat has evaporated then give them a bath a the majourity of heat has been taken away by the sweat and the remainder canbe removed by the water.
technally the best way to cool a horse after excercise is via misting fans as used in the olimpics in atlanta ‘96 when money was made avlable to scientists studding thirmoregulation in horses ‘regulation of bodt temp’. (though none of us can aford them.)
one brilliant way to stop your horse from overheating is to create a training program that can help to improve the horses natural ability to thirmoregulate. this can be acheeved by lots and lots of walk and trot a small amount of jumping and hardly any gallop as gallop dose nothing to improve the horses ability to cool as there is not enough time to heat the body sufficantly to cause much effect it is the before and after that make the horse hot.
basically thats why a bath is not best given strate after excercise. though baths are a grate way to bond with tour horse andremove any nasty bugs, dirt and grime in there coat.
p.s. ‘3rd grade science’ is a load of bull when it comes to anthing more spisific than 1+1=2
p.p.s. the whole weight loss theory i cant comment on as there are so many factoes that may affect that. (and do u want me to fo into another essay)
well that was alot longer than expeckted but i thought that someone had to comment from the other side of the arguement.
July 21st, 2009 at 11:00 am
….
I wasn’t aware ‘1 +1 = 2′ was science. I learned that in math class. Where the hell did you attend grade school?
August 13th, 2009 at 1:00 am
I totally agree with Elena and Xiana.
if you don’t sweat scrape the water actually heats up from the horses body heat, and doesn’t cool very well.(like when you jump into water with jeans on, at first it is cool but then your jeans heat up from your body heat and get HOT)
if you don’t believe it just do an experiment rinse your horse after exercise and scrape one side only and leave one side dripping and see which side is hotter.
with their fur horses don’t Evaporate very well. unless you add alchohol or body brace(liniment) to the water when rinsing.
February 3rd, 2010 at 9:05 am
I don’t agree with the last comments because you don’t take into account that during the bath the cold water runs on the horse body, taking the heat off as the warmed water pours down the horse and is replaced by the cold water (like when you take a cold shower). Also, horse hairs are greasy and the water does not always go deep into the hairs, unless you use shampoo.
Then, I don’t see why the water into the hair will not evaporate exactly like the sweat does, But I can understand how it could be less efficient than sending cool air to the horse. So for a maximum efficiency it can be good to dry the horse after the shower. But I don’t think it is that important that the horse cools down super fast, they might even get frisky if you cool them very fast after intense exercise.
By the way, mist is water in very thin drops. So misting fans are sending water.
p.s to Xiana: I am a scientist and college science is a load of bull when it comes to anything more complex than 1+1=2 (particularly in the US).