During the 1970’s the U.S. faced major energy problems. War in the Middle East reduced worldwide oil production. This led to new building codes to save energy within our homes and work places. The government required that buildings become energy tight. Before this, buildings were able to breath, and indoor air rather easily exchanged with fresh outdoor air, preventing the build up of contaminates.
Contamination from the attic and garage
Your home will lose air to the outside through air duct systems, range hoods, clothes dryers and vents. Every time you turn on your dryer, air flows through the vent to the outside. This creates a negative indoor air pressure in the home. Since nature loves an equilibrium air must come from the outside to balance the pressure.
The problem is our homes are sealed in order to be energy efficient. Where does the air come from? The outside contamination is sucked into the home from wall cavities and door frames. Most laundry rooms and kitchens are near the garage so that the garage and attic (insulation containing formaldehyde) air is sucked in the garage. Think about what is stored in the typical garage, paint, pesticides, harsh chemicals, rodent droppings and mold. The list is endless. Now items stored in garage for safe keeping are actually a part of the indoor air that you breathe.
- Since it is organic (carbon) in nature, house dust becomes the nesting grounds and food source for dust mites, bacteria, molds and cockroaches. It is a reservoir for allergies and disease.
- Chemical gases (VOC’s) will be found in home building materials, furniture and carpeting, smoke, personal care products, permanent press clothing, household soaps used for clothes and dishes.
- Let’s take a look at one gas, formaldehyde, that is commonly found in the home. Formaldehyde, the colorless, strong smelling gas is often associated with embalming fluid or preservatives in medical labs, but is much more commonly used than most consumers realize. The EPA classifies it as a probable human carcinogen. It is used in home manufacturing products such as plywood, particle board, glues and adhesives (including those used in carpets), certain insulation materials; however the greatest concern comes from pressed wood product, known as Medium Density Fiberboard (MDF) used for cabinets and furniture.
- Chemical gases never stay where they are put. They continue to emit at low levels for years, even decades. It is a common misunderstanding that out gasing is a short problem that lasts only few days or few months. People often use their ability to smell the gas as the determining factor if there are VOC’s. Once again we see that low level exposure over a long period of time is the culprit.
- Filter bio-nesting – The organic dust particles imbedded within the filter provide a nesting ground for bacteria and molds
- As air rushes through the filter, which is now a microbial nursery, germs literally shoot into the air we breathe in high concentration
Microbes need moisture to survive and grow.
- An environment with higher than 50% humidity will cause explosive growth of microbes. Although the humidity in most homes is lower than this, bathrooms, kitchens and laundry rooms can have higher levels of humidity due to water usage.
- The air conditioning evaporative coil can become a source of mold, bacteria and some VOC contamination. The dark damp conditions at the coil and drip pan is an ideal condition for the growth of mold and bacteria. This contamination is inevitable due to the nature of our air handling systems. Whatever contamination is at the coil will reach our breathable air because the airflow at the coil can travel as fast as 900 feet per min of air. This velocity is ideal for pulling bacteria, and mold spores and filaments into the airstream. They can then land in the filter, which if not changed frequently, will be a nesting ground for bacteria and mold.
Contact Della Powell directly for an IAQ Evaluation and Interview or information about quality air purification for your home or office