Indoor Air Quality Control
Why has indoor air quality (IAQ) become such a big problem? Because changes in new home construction practices that evolved out of the 1970’s energy crisis created "tight homes" that are tightly sealed, heavily insulated and very energy efficient.
While these new construction practices helped conserve energy which is good for our national security, they also "locked-in" allergenic particles, infectious agents and toxic compounds, which are bad for the health and well being of our families.
§ According to the EPA, most people in the U.S. spend an average of 65% of their time at home and much as 90% of their time indoors, and the air pollution level can be 2-100 times higher indoors than outdoors.
§ The American College of Allergy, Asthma and Immunology states that 50% of all illnesses are either caused, or aggravated by, poor IAQ.
§ According to the American Lung Association, poor IAQ is one of the most serious health threats facing us. Particles smaller than 5 microns are the cause of many respiratory related illnesses and other chronic ailments. Normally, standard furnace filters don’t remove particles that small.
§ A resent survey by the Chelsea Group determined that there are 15 million Americans that suffer with asthma and 35 million suffer from hay fever and other allergies. One third of people with allergies have triggers from gases and odors (VOCs), causing rashes and swollen mucous membranes.
§ Every day we take 20,000 breaths and breathe in up to 200 million particles: 98% of all airborne particles measure less than one micron in size.
§ The Mayo Clinic says that air cleaners attached to whole house systems work better than freestanding air cleaners.
It all boils down to four primary reasons for poor indoor air quality
1. Energy conservation measures, including tighter, well-insulated buildings.
2. Increasing use of synthetic building materials, furnishings and finishes
3. Poor design and construction
4. Occupant activities, including poor maintenance of the home and its air conditioning system
Three Basic Strategies to Improve IAQ
Source Control - The most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions. Some sources, like those that contain asbestos or lead based paint, can be sealed or removed; others, like gas stoves, can be adjusted to decrease the amount of emissions. Source control is also a more cost-efficient approach to protecting indoor air quality.
Ventilation Improvements - The second best approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors. Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house.
Advanced designs of new homes are starting to feature mechanical systems that constantly bring outdoor air into the home and exhaust the equivalent amount of contaminated, indoor air. In some areas of the country this is required by the local codes.
Air Cleaners -
According to the Center for Disease Control there are three different types of air cleaning required to improve the quality of the air in your home.
Filtration for Particulates / Allergens – 25% of the population effected
Pleated MERV 8 efficient filters are recommended for residential use and MERV 11 filters for commercial air conditioning units with filter depths of up to 5” to reduce pressure drop. Self-contained HEPA filters with integral fans ducted into the return air can be used in addition to the pre-filter for additional cleanliness.
Purification for Bioaerosols and Microorganisms – 34% of the population effected
Ultraviolet germicidal lights constantly irradiating the wet side of cooling coils and/or multiple UV lights in the return air plenum should be used to reduce bioaerosols and improve heat exchange efficiency.
Oxidation for Chemical Gases, Odor Control and Volatile Organic Compounds – 31% of the population
Photocatalytic Oxidation or Photohydroionization™ devices can be installed in the supply duct to cycle with on and off with the system fan. This technology is convenient to install when packaged air conditioning units are used in the home.
There are many types and sizes of air cleaners on the market, ranging from relatively inexpensive tabletop models to sophisticated whole-house systems. Some air cleaners are highly effective at particle removal, while others, including most tabletop models, are much less so. Air cleaners that just filter the air are generally not designed to remove gaseous pollutants.
The effectiveness of an air cleaner depends on how well it collects pollutants from indoor air (expressed as a MERV number; higher is better) and how much air it draws through the cleaning or filtering element (expressed in cubic feet per minute). The long-term performance of any air cleaner depends on maintaining it according to the manufacturer's directions.
Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source. Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources. People with sensitivity to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.
For most indoor air quality problems in the home, source control is the most effective solution.
Type of
Formaldehyde Tobacco smoke, carpet, furniture, fabric, building materials
NO2, SO2 & CO Fuel-burning appliances that are improperly vented, attached garages
VOC’s Household cleaners (isopropanol), pesticides, personal care products, scented candles (terpenes), cosmetics (acetone), mothballs (naphthalene), dry cleaned clothes (tetrachloroethylene)
Ozone Motors, copy machines, other office equipment
Mold, Mildew, Bacteria Damp basements, areas where standing water is present
Dust Mites Warm moist places
Particulates People, ash from fireplaces, dust, soil from outside, carpet, fibers, hair
Pet Dander Household pets
Pollen Plants from outside
Your unaided eye can see particulates that measure about 10 microns and larger. An optical microscope can see particles down to about 0.3 microns. To see smaller sizes, like viruses, an electron microscope is necessary.
brings in outdoor air while exhausting contaminates.
Fresh Air Ventilator -
Motorized damper lets in outdoor air when the fan comes on
Ultraviolet air treatment using UV-C light in the ductwork or irradiating the wet side of the cooling coil in the air conditioning unit reduces bacteria and infectious agents that can survive in the dark confines of your air conditioning system.
How does Ultraviolet light do that?
UV light is invisible and right next to visible light in the spectrum. It has three bands -
The Sun irradiates all 3 types, but only UV-A and UV-B make it through the Earth’s atmosphere. UV-C is filtered out by the atmosphere and has been proven to be a highly effective germicide.
UV irradiation technology has been used in water treatment plants, hospitals, pharmacies and professional kitchens for many years.
These biological agents need nutrients and moisture to thrive. Reducing available moisture is the best method of control, i.e. eliminating roof leaks, plumbing leaks and higher than normal humidity.
Weatherproof
Housing
Common household furnishings such as draperies, carpeting, wallpaper, paints, stains and furniture may continue to "off-gas" potentially toxic VOC fumes for a long time after application or installation. Synthetic materials of construction release formaldehyde as a vapor. That chemical is used in making of the adhesives found in compressed wood used to manufacture built-ins, cabinets and OSB I-beams used for joists and trusses.
Using ventilation removes the potentially toxic contaminates from the space. Using oxidizing technology can break down harmful chemicals to their basic elements.
PHI CELL – PhotohydroionizationÔ Technology
installed in the supply duct oxidizes organic compounds eliminating harmful gases, their odors and controls bioaerosols throughout the entire home. The combination of UV light enhanced by a hydrated quad-metallic compound target develops an advanced oxidation reaction. This process produces hydro-peroxides, super oxide ions, ozonide ions and hydroxides to purify the air. Microorganisms can be reduced by over 97%. Cell lamp replacement is recommended after 25,000 hours (~3 yrs).
Whole house Photocatalytic Oxidation (PCO) air cleaning system reduces odors from VOCs and has a first stage deep pleated UV resistant MERV 11 filter. The filter can last up to 6 months and is easy to change out. The UV light powers photocatalytic oxidation to destroy odors by decomposing the odor molecules not by masking them. It uses some of the same principles of operation as an automotive catalytic converter. The air passing through the catalyst comes in contact with a UV energized titanium dioxide coated grid. The titanium dioxide molecules react with airborne odor molecules and break them down to harmless components. The odor reduction stage requires little maintenance except UV lamp replacement every two years. This system is best used with a split air conditioning fan coil housing and should be mounted on the return side.
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There are a variety of furnace filters types and sizes available.
Air cleaning efficiency is measured by "MERV Ratings" (Minimum Efficiency Reporting Value), the higher the MERV number the higher the efficiency of that filter. Generally the more expensive the filter is the more restrictive it is, the more dense the media is and the greater the filtration efficiency. Higher efficiency requires higher-pressure drop and the requirement for more energy or a greater surface area.
Deep media
high efficient HEPA MERV 20
filter cabinet with with booster fan
box filter of built in the cabinet
different efficiencies
and long life
Pleated MERV 8 filter -
fits 1” filter grille frame and comes in 1”, 2”
or 5” deep casing with air tight gasket
Free Standing
with condensate pump
removes over 100 pints per day (80°F, 60% RH)
Removes 100 pints per day and goes in a crawl space
Whole House Dehumidifier 90 ppd
Steam
20 gpd
12 gpd