Thermal Comfort: Why Even Healthy People Should Avoid Drafts
A draft, even a slight one, disrupts the thin protective layer of warm, moist air directly adjacent to your skin
As a result, you start losing heat much faster, up to hypothermia. And this can already harm your health, sometimes quite significantly.
Now let’s break it down in detail. I’ll start by saying that when it comes to drafts, it’s all very individual. There are people with absolute health who can sleep on wet ground in the rain and wind without getting sick.
But for most people on Earth, drafts regularly create problems.
And here’s why:
Two damaging factors of a draft
With “complete calm” above the skin surface, a thin and relatively stable boundary layer of warm and moist air is formed, which:
- Prevents rapid evaporation of moisture from the skin
- Limits heat loss through convection
So, even a light draft can damage this protective layer. As a result, the total heat loss from the skin will increase significantly.
How much will it be in numbers?
Summing up data from open sources, even very weak air movement, around 20 cm/sec, at the limit of our sensitivity, can increase the rate of moisture evaporation from the skin by 2-3 times.Heat loss from a draft depends heavily on specific circumstances: individual skin moisture/dryness/temperature, air humidity and temperature. So, the estimate provided is more than approximate.
Nevertheless, in most cases, these losses are quite significant and cannot be ignored if you want to achieve full comfort indoors This means that heat loss will also increase proportionally. For most practical cases, this is quite a lot.
Plus, the situation is usually worsened by a sedentary lifestyle. We sit at the same desk, in the same favorite position. Therefore, if you’re unlucky with the draft, you’ll be freezing in the same spot. Constantly. For weeks, months, years. And this can lead to serious consequences.
Find out more about how and why local hypothermia can harm your health in our article “Thermal Comfort. Why When Your Feet Are Frozen, Your Throat, Joints, Kidneys Hurt...”.
Related materials: “Why Clothing Doesn’t Always Protect Against Drafts”.
