Most people only think about humidity when it comes to summer. But, when it comes to climate control, humidity is just as important to consider in the wintertime, especially with these cold, dry Rochester winters. It just plays a different role.
In the winter, humidity - or lack of humidity - is important to consider. It doesn't matter if you live in Rochester, or the finger lakes, adjusting for humidity in the cold weather goes a long way toward comfort and even safety. Here are a few factors to keep in mind about the role of humidity in home comfort.
First off, what is humidity, exactly? Understanding that will help make its role in home comfort clear. Basically, humidity is water vapor, or water in gas form, in the air.
When it comes to measuring it, you’ve probably heard the terms “absolute humidity” and “relative humidity.” Absolute humidity is the actual amount of water vapor in the air. It’s measured as grams of vapor per cubic meter of air.
Relative humidity factors in air temperature and is expressed in a percentage. That’s what you usually hear about in weather reports. The percentage is what amount of the air’s capacity to hold water is actually holding water.
This is important because colder air can’t hold as much moisture as warm air. Relative humidity adjusts its percentage for that.
50 percent relative humidity in 90-degree air, for instance, has more moisture in it than 50 percent humidity in 40-degree weather. That’s because the warmer air can hold more moisture.
When it comes to home comfort, relative humidity is most important. You want to adjust for temperature when determining how much moisture is in the air. The lower the temperature, the less percentage of humidity you’ll want.
When it’s over 50 degrees Fahrenheit outside, you can have up to 50 percent humidity inside. If it’s between 20 and 49, don’t go over 40 percent. If it’s between 10 and 20 degrees outside, keep it under 35 percent and under 30 percent if it dips down to zero.
If the humidity in your home goes outside these guidelines, you could run into some problems.
When your humidity is too high, there’s more moisture in the air than is necessary. This affects home comfort and can even cause some health issues. It depends on just how humid it is.
For starters, all that moisture can end up costing you extra money in energy bills. That’s because moisture isn’t a great conductor of heat. The more humidity, the harder your system works to heat your home.
Elsewhere, slightly high humidity can cause mugginess. This can make people in the house feel a little hot or generally uncomfortable. As the humidity climbs higher, you may notice condensation on your walls or in your window panes.
But, high humidity can become a bigger problem than just home comfort, especially in colder weather. That’s because in the winter, you’re more likely to keep windows and doors closed all the time. This seals in moisture — and other unwanted elements — in your home with no way to escape.
You’ll want to adjust this before things get worse, however. Excessive moisture can make your home a breeding ground for bacteria, mold, fungi, and even viruses.
Often, people who suffer from allergies or asthma begin experiencing symptoms more often. Those symptoms may also get worse over time. Meanwhile, mold, mildew and fungi can damage your home if they take hold.
Low humidity occurs more often in the winter than in the summer, also affecting your home comfort. That’s because two factors can work at the same time to create dry air in your home.
First, the air outside is cold and so it’s holding less moisture than warm air. That cold, dry air is seeping into your home through cracks, drafts and any space it can find. This causes your heater to turn on.
It warms the air but doesn’t add moisture. This means the air’s capacity to hold moisture rises as the temperature goes up. But, with no extra moisture, the relative humidity goes down.
This creates a low-humidity situation because the original, cold air is dry. Then, the temperature rises, creating more capacity to hold moisture but not adding any.
Fortunately, low humidity in the home doesn’t cause as many problems as high humidity. However, there are still some undesirable effects.
Static electricity is one. As you move around, you potentially build up small charges of electricity. In humid air, the water vapor acts as a conductor and moves the charges away from you.
When it’s less humid, the charges build up rather than disperse. When they finally discharge because you touched a conductor, like something metal, you’ll feel a shock.
A more severe problem with low humidity is nosebleeds. If the air around you is dry most of the time, the membranes inside your nose can dry out and begin to crack. This causes your nose to bleed, especially if it’s already irritated due to a cold, allergies or other factors.
For these reasons, it’s important to control humidity for home comfort. Not only will you be healthier and more comfortable, but you may save some money on energy bills, too. Next week, we’ll look at how to measure your home’s humidity and raise or lower it as needed.