Humidity levels in a home can have a significant impact on human comfort for better or worse. Moisture levels in a home are also a factor in the continuing well-being of your home and possessions, and they play a role in how affordable it is to heat and cool your home in the short term but also over the long term. Humidification is the process through which you add water vapor to the air. Doing so can make the home more comfortable, provide health benefits, lower your costs, and help protect your home.

Relative Humidity and Home Comfort

The term humidity refers to the concentration of water vapor in the air. The term relative humidity—which is often abbreviated RH and expressed as a percentage—indicates the concentration of water vapor in the air relative to the temperature. Consider that at a temperature of 68°F, air can hold twice as much water vapor as it can at a temperature of 50°F. Therefore, winter air is drier than summer air, and why the heating season is when we want to humidify our homes rather than dehumidify them.

The ideal RH in the wintertime is 30-50%. Below 30% RH, you can experience dry skin, itchy eyes, and irritation of the throat and nasal passages. Low RH will also make you perceive the temperature as lower than it is and thus make it harder to be comfortable. High humidity makes an indoor space feel stuffy. People may experience breathing difficulties and lethargy. It also makes the environment more conducive to mold spores, dust mites, viruses, and bacteria. Within the 30-50% range, there is a great deal of room for personal preference, and your ideal RH in that range depends on how it makes you feel.

The Downside to Low Humidity in the Home

As mentioned, low humidity can affect your health and make you feel less comfortable. Although we normally associate summertime with allergies, low humidity can trigger reactions in people with allergies, asthma, and other respiratory conditions. Low RH will also make you feel less warm, and most people will compensate by turning the temperature up and thus spending more on heating. A lack of moisture vapor also causes high static electricity, and it is bad for the home itself. It not only dries out the wood that makes up your home but also hardwood floors, furniture, musical instruments, books, and so forth.

Heating Your Home

There is a wide range of technologies used to heat homes in San Marcos and the neighboring communities. These include furnaces, boilers, heat pumps, and ductless mini splits. These technologies take different approaches to heating air that is then distributed to the living space. A common misconception is that heating your home dries it out. This isn’t technically true. The air becoming drier is a byproduct of heating the home. The winter air has a lower RH than the air in the home. Your heating system works by drawing air from the outside in and heating it. Therefore, it’s continuously drawing in drier air and thus suppressing the overall RH of the home. The only way to offset this is humidification.

The Building Envelop and Low Humidity

In simple terms, a building envelope refers to the separation of a home’s interior and exterior. It is often used within the context of a home’s insulation and ventilation. Modern homes are designed to have a tight seal because that approach is more energy efficient. It also makes it easier to control temperature, RH, and other indoor environmental factors more precisely. In an older home, there may be factors that exacerbate the scenarios described earlier. Poor insulation leads to a loss of heat energy, which requires the heating system to run even more often. And too much natural ventilation, such as cracks in the foundation, can allow cold and dry air to seep into the home.

Home Ventilation and Home Humidity

To maintain an ideal RH as efficiently as possible, you want the home to have a tight seal and to be well insulated and well ventilated. If you live in an older home, you may want to schedule an energy audit and use that report to upgrade your home. In a more modern home, it is necessary to ensure that you have adequate ventilation, not just for the purposes of humidification but for indoor air quality overall. Most experts recommend mechanical ventilation. Two of the most popular options are heat recovery ventilators and energy recovery ventilators. HRVs and ERVs not only let you control the influx of fresh air into a home but recapture heat energy to make heating your home less expensive.

Using a Whole-House Humidifier

The best way to ensure optimal RH in your home is to invest in a whole-home humidification system. It will allow you to set your RH and be more comfortable. This will also allow you to run your heating system at a lower temperature, but not as often. There are several different configurations on the market. Three core options are bypass, fan-powered, and steam humidifiers. Bypass dehumidifiers—sometimes called furnace dehumidifiers—are often installed in the ductwork. Forced heated air from the heating system is passed over a water tray. Fan-powered dehumidifiers are similar but more efficient. Some require the central blower while others have their own. Steam humidifiers are the fastest and most efficient and work by boiling water and creating a water vapor.

Using Portable Humidifiers and Ceiling Fans

You may also want to use portable humidifiers. This allows you to set a higher RH throughout the home, such as 40-50% while you use portable units to enjoy 30-40% in the rooms that you are using. Experts also recommend ceiling fans in all high-use rooms and that they are set to rotate in a clockwise direction during winter. While a ceiling fan will not affect RH directly, it does help to ensure that that temperature and water vapor are evenly distributed throughout the room.

Too Much Humidity in the Home

An RH above 50% is bad for your health. It is also bad for the indoor environment as it makes it more conducive to mold, dust mites, viruses, bacteria, and so forth. It is unlikely that your home would naturally be above 50% RH in winter. It is, however, possible to introduce too much moisture into a home using humidifiers, which is why it’s important to have a thermostat with a humidity sensor.

Your Local Humidification Pros in San Marcos

Oak Island Heating and Air Conditioning is a family-owned and operated business that has been serving San Marcos and the surrounding areas for more than 20 years, and our industry experience in this region dates to 1984. Our company provides installation, maintenance, and repair services for air conditioners, gas and electric furnaces, heat pumps, mini splits, and hot water and steam boilers. We also provide installation, maintenance, and repair services for a wide range of indoor air quality equipment, including humidifiers, dehumidifiers, air purification systems, air scrubbers, and whole-house fans. If you’d like to learn more about those options or want to schedule an appointment, contact us today.

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