Humidity is a fact of life in Arlington, Fort Worth, and Dallas come spring and summer. Mix in the raw heat of Texas and the Southwest United States and it’s pure hell in July, August, and September.
Homeowners understand the relationship between raw heat and their air conditioners: It’s hot outside, so the AC will run more frequently to keep the house cool.
But what’s the relationship between humidity and your air conditioner?
In the next few posts we take a closer look at humidity, its impact on the heating, ventilation, air conditioning (HVAC) equipment that runs all summer long and costs a lot of money to operate, keeping our Arlington, Fort Worth, and Dallas-area homes cool and comfortable when it’s hot and sticky outside.
The Science of Humidity
Humidity is the water-vapor content of air and indicates the likelihood of precipitation, dew, or fog. There are three measurements of humidity: absolute, relative, and specific. We’re only concerned with absolute and relative.
Absolute humidity is the total amount of water vapor present in a given volume of air. Temperature is not taken into consideration. Absolute humidity changes as air temperature or pressure changes.
Relative humidity is the figure given in weather reports and the number most people are familiar with. Relative humidity measures the current absolute humidity (water vapor) present in the air to the saturation point at the same temperature and is usually expressed as a percentage.
Humidity is a fundamental factor that defines any habitat and is one of the determining factors how animals and plants survive in any given environment.
Humans cope with hot, hot weather by perspiring and breathing. If there are high temperatures and high heat, the duo often found in Arlington, Fort Worth, and Dallas summers, a person will be sweating but the sweat won’t be drying on the skin. When perspiration is dried by the air there is a cooling effect on the body.
Residents of Arlington, Fort Worth, Dallas, Texas, the Southeast and Southwest United States — heck, it seems the entire globe these days — depend heavily on air conditioning to survive hot and humid summers.
How Humidity Impacts Your Home
The relative humidity in your home impacts your comfort and health. When the humidity is high, occupants feel hot and sticky because evaporation of perspiration is slowed.
High humidity for an extended period in the home also causes mildew or mold. In basements — not an issue for most residents in Arlington, Fort Worth, and Dallas — high humidity also causes beads of water to form on exterior walls.
When your air conditioning system is working efficiently, it removes the proper amount of heat and moisture from the living areas, resulting in a more comfortable environment.
Depending on location and outdoor heat and humidity variables, indoor humidity ranges from 40 to 60 percent, although for Arlington, Fort Worth, and Dallas, many HVAC contractors and service techs recommend 40 to 50 percent.
If you are unsure of your home’s humidity percentage, as the service or repair tech to check it for you next time he comes to the house for a semi-annual checkup of HVAC equipment. You may also purchase inexpensive humidity monitors (images) at a local home improvement center like Lowe’s, Home Depot, among others.
If your HVAC equipment is not functioning properly, you may feel hot and sticky regardless of the temperature setting. When humidity is right, the AC unit works harder to keep the home cool, which usually means higher electric bills.
It’s definitely worth keeping an eye on the humidity levels in your home and how your HVAC equipment is functioning, especially if you have an older system or it was not “right-sized” from the start. If the AC unit works longer and harder without providing the desired results, it adds wear and tear to the equipment and may prompt more frequent service and repair calls to the home.
Two other signs that your home is too humid include a damp or musty smell in parts of the house and foggy windows.
So you are aware and to provide a contrast between summer and winter, a lack of humidity in the winter also impacts your home.
Cold air does not hold as much moisture as warm air, so a dramatic drop in moisture levels during the winter can actually leave you feeling cooler even though the thermostat is set to a warm temperature.
Low relative humidity causes a person to feel chilled, even at 70 degrees, because perspiration evaporates at a rapid rate. Low humidity also causes dryness of the skin or throat, dry nasal passages, irritated eyes, aggravated sinuses, and may exacerbate colds and other respiratory ailments.
Strategies for Dehumidification
The most efficient and reliable way to manage the moisture in the home is to have an Arlington, Fort Worth, or Dallas service contractor install a dehumidifier directly into the HVAC system.
However, there are advantages and disadvantages to using dehumidifiers, which we will look at in greater depth in the next post. For now, here are some easy tips to become more “humidity efficient:”
Easy Ways to Become Humidity Efficient
Be aware that what you do in your home — cooking, drying clothes, taking hot showers — adds to humidity already in the air and makes your air conditioning less efficient. Opening doors and leaving windows open to “let a breeze in” adds moisture.
- Cover pots and pans when cooking to keep moisture from entering the home’s air
- Install and use ventilation fans in the kitchen (above the stove) and in bathrooms if you do not already have them
- Do not line-dry clothes inside, although we’re not sure line-drying the wife’s delicates will make much difference
- Keep doors and windows closed during the day, especially in the summer — meaning you will continue to yell at the kids to close the doors and not to leave the back door open to entice the family dog outside on a hot day
- Keep your air conditioner coils clean. Use a garden hose and carefully spray away any dirt and debris (lawn clippings especially) stuck in the coils. This allows the system to work more efficient and may even contribute to lower utility bills.
- Vent the clothes dryer outside (if this isn’t already done)
- Install a smart thermostat you can program for power-saving settings
- Install ceiling fans to better circulate cool air
- Put a ground-moisture barrier in your crawl space (if applicable) to help decrease inside humidity
- Make sure that furniture and curtains are not blocking air vents and impeding air flow throughout the house
- Pay attention to carpet: It can actually trap moisture, especially if it’s installed directly on the concrete. This is also bad because allergens grow under these circumstances. Consider using area rugs that can be removed and cleaned periodically instead of wall-to-wall carpeting.
Using Your Air Conditioner to Control Humidity
With spring upon us and summer a stone’s throw away, high humidity not only brings sticky discomfort but also the potential for another problem: mold.
High levels of moisture in indoor air can create the perfect conditions for explosive mold growth, particularly in gypsum wall boards, wood window casings, and vinyl wall coverings.
Using your thermostat you can bring the home’s humidity levels down to a comfortable level and make it harder for mold to thrive. Here are a few tips:
- Leave the thermostat fan set on AUTO. This is preferable to letting the blower fan running continuously, which causes condensation on the evaporator coil to be blown back into the circulation instead of being allowed to drain out of the unit as intended.
- Some AC units will continue running the fan up to three minutes after the compressor shuts down. If you are uncertain about this, ask the service or repair tech next time he’s at your home for a semi-annual checkup. He may be able to disable this feature, allowing the fan and compressor to stop at the same time.
- And what do we always say? Don’t forget to change the filters on the air conditioner regularly. It contributes to a healthier overall HVAC system and presents the cultivation of mold and other harmful airborne bacteria.