Table of Contents
Home Humidity Control | Why Its Important for Comfort & Health - Humidity is important to our home and health and it is important to maintain the correct humidity in our homes and workplaces for our health. What is humidity? Humidity is simply little water droplets in the air. Cold air is nearly saturated with these little water droplets because the contents of cold air allow the air to hold more water droplets or humidity. As air is heated it expands and holds less humidity.
Home Humidity Control | Why Its Important for Comfort & Health
When you heat the air in your home using a furnace, boiler, or heat pump this air expands and becomes drier. It is air with less humidity relatively speaking before it was heated and compared to the outside air. Air that is 30° F with 80% humidity will only be 15% humidity at 75° F.
That is a big difference in humidity levels in the home after the air is heated. Granted, you are not heating air from 30° F to 75° F with your furnace. Depending on the setup of your thermostat and heating system, you are most likely heating air that is 68° F to around 70° F to 75° F depending on the thermostat setting. The point is unless you have a source providing humidity to the air stream, you are merely reheating dry air from inside the structure.
There will be minimal infiltration humidity, but the infiltration humidity will never be enough to bring the humidity levels up to healthy levels inside the structure for the inhabitants, plants, and furniture.
Home Humidity Control | Why Its Important for Comfort & Health - The Study of Psycrometrics
Psycrometric Chart
Yes, that is psycrometrics and it has nothing to do with psychology. It is the study of air and its properties. It is used in HVAC by HVAC technicians and HVAC engineers to determine the contents and makeup of the air. The HVAC industry uses Psychrometric Charts to plot the contents and makeup of the air.
Psychrometric Chart
Using the Psychrometric Chart, a technician or engineer can determine the relative humidity, enthalpy value, dry-bulb temperature, wet-bulb temperature, dew point, and vapor pressure if they have a few of the listed values. With this data, engineers and technicians can solve problems or assign values and setpoints.
For example, an economizer system that is controlled by the building automation system can be controlled by an enthalpy value. This value associated with an And Gate will only allow the economizer to open under certain conditions that will allow the mechanical cooling systems to shut down and take in free cooling from outside the structure.
The temperature, humidity, and all the contents and make-up of the air will be optimum for free cooling using the economizer. By knowing the contents and makeup of air one can set up HVAC systems to work better and one can also use the data provided by knowing the contents and makeup of air to troubleshoot problems with HVAC and building systems.
Why Its Important for Comfort & Health - Indoor Air Quality and Humidity | Home Humidity Control
It is essential to maintain the correct levels of humidity in the home for many reasons. Comfort is one factor, indoor air quality is another factor, and saving energy is another factor. All three are related in one way or another, but each is a separate factor. If you reside in the northern climate regions where the average temperatures are less than 20° F, you want the indoor humidity to be relative to outside air humidity.
High Humidity and Home Moisture Problems
Temperatures about 20° F the recommended relative humidity inside the home or business is 35% to 45%. The construction of the home or business will also determine the amount of humidity. If you have vapor barriers and good tight windows and doors, you need an excellent mechanical ventilation system. Humidity levels can rise above 60%, causing excessive moisture inside the structure, which will lead to mold, mildew, and possible water damage.
Make sure you have a good mechanical ventilation system inside your structure to avoid moisture issues. Bathroom ventilation fans, hood fans over stoves, and other types of exhaust fans inside the structure pull out excessive moisture when cooking or showering. If you have this problem, it most likely shows up in the form of mold growth inside closets, kitchens, bathrooms, and ceilings. Additionally, if you have excessive moisture problems your windows will frequently fog or have a lot of moisture on the windows.
Home Humidity Chart for Health | Ideal Humidity Level for the Home
Why Its Important for Comfort & Health - Low Humidity | Home Humidity Control
Low humidity levels cause problems also. Static electricity, dry skin, dry sinuses, and other health problems, including increased flu illness, can occur. Additionally, low humidity levels cause problems with wood inside the home. To test for low humidity levels in the home, make a glass of ice water and set it somewhere away from the kitchen or bathroom.
If, after five minutes, water droplets do not form on the outside of the glass, then you have a problem with low humidity levels in your house, and you need to get a humidifier. If your structure is suffering from low humidity levels, you will also feel cooler, resulting in a desire to turn the thermostat up. Therefore adding a whole-house humidifier to the HVAC system will cause you to turn the thermostat down because with more humidity you will feel warmer.
The correct levels of humidity in your home can increase comfort, save you money on your utility bills, and make you healthier.
High Humidity in the Home
If you have high humidity in the home there are ways to reduce it. High humidity is not likely the problem in the winter when your air conditioner is running. The air conditioner is a humidifier that removes moisture from the air. If the air conditioner only serves a part of the house you can have issues in the unconditioned areas. For example, in the basement. This is the area where you can use a dehumidifier to remove excess humidity. If you are cooking then use the hood vent over the stove to ventilate the steam from cooking. When you are showering, turn on the bathroom vent fan to pull high humidity from the shower steam.
Lastly, seal your house better with vapor barriers. Lots of air leaks occur at doors and windows. These places leak moist air into the house. Sealing those leaks will help reduce high humidity levels in your home.
Home Humidity Control | Why Its Important for Comfort & Health - Warm Air Expands
Remember that your furnace or heat pump DOES NOT remove the moisture from the air. The furnace or heat pump makes the air warmer and warmer air expands, making the percentage of moisture in the air less than when it was cold. Relative Humidity is the amount of water vapor percentage that is in a given amount of air at a given temperature.
Air is considered to be saturated with moisture when it reaches 100% relative humidity; however, you can quickly change the 100% relative humidity in the air by increasing its temperature. Decrease the temperature, and the moisture condenses from the air, or it can be considered rain. When you heat the air, you increase its volume, and without a humidifier adding moisture to the air, you are decreasing relative humidity.
Adding a whole-house humidifier to your home will always help maintain higher levels of moisture in the house and that will counter all the problems associated with low humidity levels.
Home Humidity Control | Why Its Important for Comfort & Health
