Relative Humidity
Humidity Index Varies Based on Where You Live
Relative humidity is the amount of water in a specific volume of air at a certain temperature. The technical definition for relative humidity is the actual vapor density divided by the saturation vapor density (i.e. the density of vapor that would mean the air is saturated); this is written as a percentage. In the U.S., we may measure relative humidity in grains per cubic foot; alternately, it may be recorded in grams per cubic meter. The warmer the air, the more particles of water it can hold.
What Does This Mean to Us?
In some hot states we often hear about the humidity index. If you are afflicted with air-related issues, you may need to know the expected humidity level in order to plan your day. On the other hand, high humidity does affect everyone, even those without asthma or other breathing issues. It makes the air feel warmer and can cause you to overheat.
The reason for this is that your skin is not breathing effectively enough to keep you cool. In drier heat, when the air is hotter than the body, the blood moves closer to the skin’s surface and cannot cool down on its own; at this point, sweat glands kick in to produce electrolytes on the skin’s surface. The evaporation of sweat cools the body under usual conditions.
On exceptionally humid days, though, you may find that you feel even weaker and more fatigued. This is because your body senses that the air is warmer than it really is.
If the temperature and the humidity are high, it may seem as though the temperature is up to 30 degrees higher than actual. It’s the opposite effect of winter wind chill factor, wherein the temperature seems lower than it reads on the thermometer.
For example, if the temperature is 90 degrees and the humidity level is 90 percent, the combined effect of this is that it will feel like 122 degrees. This can result in sunstroke or heat exhaustion. A heat index (temperature and humidity) of 80 to 90 causes fatigue, 90 to 105 makes sunstroke and heat exhaustion possible and anything above that makes sunstroke and heatstroke likely. Over 130 makes your body highly likely to suffer from serious heat-related complaints.
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What Does Relative Humidity Mean Inside Your Home?
Obviously, heat is required in the winter for comfort inside your home. The colder it is outside the more we use our furnace, resulting in drier air. You may need to increase the humidity level inside your home in order to feel warmer.
For example, if the room temperature is about 70 degrees and the relative humidity is only 20 percent, it will only feel like 65 degrees; to compensate, we may be inclined to turn up the thermostat. But if the room temperature is 70 degrees and the humidity level is 70 percent, it will feel like the room temperature is 70 degrees.
Raising the humidity level in your home can keep down your home heating costs. It can have other benefits to your health, as well.
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