Improved quality of Indoor Air has direct relationship not only with general well-being and good health of the inhabitants but also with long life of interior fixtures, furniture, fabrics, carpets and electronics.
An acceptable Indoor Air Quality (IAQ) is defined as; in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80 percent or more) of the people exposed do not express dissatisfaction.
Most of the time Indoor pollutants of concern are as follows;
Gases and Vapors; Volatile and semi volatile organic compounds (VOC): 300+ compounds, such as formaldehyde, benzene, and toluene.
Inorganic Gases; CO, CO, SO, NO×, NH, Radon
Fibers; Asbestos, fibrous glass, man-made fibers, cotton, textiles
Dusts; Allergens, house mites, pollens, feathers, smoke (tobacco, wood coal)
Microbes; Bacteria, protozoa, fungi, viruses
Conventional residential forced air heating/cooing system comprises duct work with supply and return grilles connected with fan and cooing coil. These types of system don’t take in to consideration level of filtration for indoor environment.
A whole house air cleaner is effective in cleaning indoor air and bringing it to desirable quality. It moves large amount of air through the cleaner and removes particles all the way down to submicron sizes.
This cleaner can be as simple as 1 in. filter installed in the furnace, in the return duct, or at the return grille. These are available in low to medium efficiency range. These (1 in type) have limited media surface area and typically last up to three months. Deep media air cleaners with 5 in. filter have longer life and much higher media surface area and offer up to one year life. These cleaners offer filter efficiency up to MERV 16, which means 95% filtration for all particles down to 0.3 micron particle size. This level of filtration removes all dust and most of the bacteria.
Cleaner is installed next to the air handling unit on the return side. It is secured to the air handler using sheet metal screws.
It come in multiple sizes and are rated for airflow rate. Air flow rate must match with the design flow rate of the HVAC System. Other performance aspects are filtration efficiency, pressure drop on HVAC system air flow and filter replacement/ cleaning life.
These are better in performance as compared to a portable air cleaner due to large volume of air. Number of air changes per hour with whole house air cleaner may be eight to ten times as compared to portable cleaners. More air changes per hour mean faster and better filtration of particles at all sizes. Hvac suppliers near me