|
Many household activities such as laundering and bathing increase the humidity level in the home. In the winter, your heating system tends to dry up this humidity and a humidifier is required to bring the humidity up to a comfortable level. In some cases however there is too much humidity. If the house is not tightly sealed, moisture may make it's way in through cracks and crevices and moulds may form. Also condensation will form on the windows. If high humidity is not treated, allergenic reactions and respiratory diseases could result from moulds or spores that could appear anywhere there is dampness.
Humidity is the amount of moisture or water vapor in the air. It can come from any number of sources. People and pets produce moisture when they breathe or perspire. Plants produce moisture. We add water vapor through routine household activities such as cooking, showering and bathing, laundry and dishwashing. Moisture can also enter the home from leaks in the roof and walls, the surrounding soil, a basement or crawlspace, and through uncontrolled air leakage.
An excessively humid indoor environment provides a breeding ground for molds and other biological contaminants, which can lead to serious health problems. A survey by Health Canada found that 38% of Canadian homes have either excessive dampness or molds. Canadian Mortgage and Housing Corporation (CMHC) feels so strongly about this problem that they have concluded “people should not live in moldy houses.”*
Too much humidity in homes will show up as condensation on windows, wet stains on walls or ceilings, moldy bathrooms, musty smells (particularly in the basement), and frost buildup in the attic. Allergic reactions are the most common problem associated with biological agents.
On the other hand, indoor air that is too dry can also result in a range of adverse health effects, such as headaches, itchy skin and nosebleeds. Various medical studies suggest that by adding humidity to the air we can avoid upper respiratory infections. Excessively dry air can also cause an annoying build-up of static on carpets, clothes and hair. Humidity is required to maintain the beauty and life of hardwood floors, furniture and artwork.
Fortunately there is a happy medium when it comes to humidity in homes. Acceptable or comfortable humidity levels will actually vary from season to season, from house to house, and even between rooms in the same house. Generally, the optimum humidity level in the home is between 35% and 55%. Individual sensitivities and needs will determine which end of this range is best for each particular home and family.
High humidity can be treated with a device called a "heat recovery ventilator". It is an energy efficient fresh air device that will not only lower the humidity level, but will also provide ample fresh air for your family. This device is installed in the basement and is ducted into your furnace system.
Just opening windows to provide fresh air will not solve the problem as it may create negative pressure which could cause the flue gasses to reverse down the chimney. Also opening the windows would not be very energy efficient in the winter.
|
