Kuiper wears an orange dishtowel like a cape.

On Evaporative Cooling

Not all heroes wear capes. Some wear dishtowels.

It was really heckin’ hot at Oregon Star Party a few weeks ago! We had 2 days of 104 F (40 C) in the shade!! In addition to a canopy, reflective tarps and a cooler full of frozen water bottles, I took advantage of evaporative cooling to help keep Kuiper comfortable.

In general, it takes energy for a substance to melt (change from solid to liquid) or evaporate (change from liquid to gas.) Water in particular requires a LOT of energy to change phases because individual molecules tend to stick together. Water molecules like to form hydrogen bonds with their friendos. The strength of these bonds is proportional to temperature (& pressure); they are strongest below “freezing” (the temperature at which ice forms.) Turn up the temps and the molecules start vibrating faster: the ice melts. Turn up the temp even more, and the (now liquid) water starts to evaporate.

Water doesn’t have to be boiling to evaporate. Even at lower temps, some molecules vibrate faster than others. The more energy an individual molecule has, the more likely it is to “escape” into the air. When a water molecule evaporates, it reduces the average kinetic energy of the water left behind. We perceive decreases in average energy of something as being “cooler” and increases in average energy as being “warmer”; temperature is a measure of kinetic energy.

If you put cool water on your skin, the water will absorb some of your energy (“heat.”) Unless you’re somewhere with high humidity, this will in turn make the water more likely to evaporate and carry that heat away from you. Our bodies attempt to do this automatically through sweating. Dogs can only sweat through their paw pads; they use panting as an evaporative cooling mechanism instead. Unfortunately, it’s not as effective.

Depending on your dog’s coat type & where you live, you can try helping your dog on a hot day by soaking a dishtowel cape in water, or simply wetting down their fur (side note: this is one of the reasons I don’t use spray bottles as punishment.) If you have a less heat tolerant breed, or live somewhere humid, I recommend hiding inside. Preferably somewhere with AC. 😂

Original post: https://www.instagram.com/p/BnJYjVEAqFZ/

Leave a Reply

Your email address will not be published. Required fields are marked *