The quality of the air that we all breathe in our homes in Winnipeg can be managed in many ways. It is important to first understand the problem or nature of the situation so that your efforts and expense can best be directed towards an effective product and solution.
Most air quality issues can be classified in 3 ways.
- Dust or particle control
- Odor control
- Mold, Bacteria and Virus control
PART 1: Dust or particle control
The MERV rating or performance efficiency of air filters range from 7 -12 for standard type furnace filters from plain to high density pleated. Higher rated (13 to 16 MERV) filters are quite costly and are more often used in hospital type settings. These are more commonly known as HEPA Filters. (High-efficiency particulate absorption)
Most residential filtration requirements are meant to capture airborne particles such as:
- Household lint and Dust
- Pet dander
- Dust mites
- Carpet and textile fiber
Some higher rated filter manufacturers also make claim to control bacteria and odors but are really limited in providing a complete solution. We will provide more detailed information on this in Part 2 and Part 3 of this article.
Higher is usually Not Better
You may think that a higher MERV rating would automatically be better, but it’s not. The higher the MERV rating, the smaller the pores are for air to flow through a furnace filter. This can create more resistance in airflow than a duct system is designed to manage, thus making it counterproductive. Reduced air flow in your system can actually worsen the air quality in your home and put a damaging amount of pressure on the fan of your furnace or AC system. It is therefore worth doing some research.
Static Pressure is the internal reading of air pressure within the air ducts of your Hvac system. Most furnace manufacturers recommend a maximum of .5” wc to ensure that efficiency and performance ratings can be delivered. An example of this would be that a system with a clean Merv 7 filter produces a Total static pressure reading of .5” and increases to .9” or higher with the use of a clean Merv 12 filter. Find out what the highest MERV rated filter is that still allows for maximum airflow in your system.
A duct system with high Static Pressure over 1”wc becomes noisy and will result in overheating of the furnace or freezing up the a/c cooling coil. This of course eventually leads to premature failure and repairs.
High efficient pleated filters have more surface area and will trap finer particles. The result is that the higher cost will actually require them to be replaced more frequently raising the cost even more.
When circumstances are proven that a higher rated pleated filter is required, a 2” or 5” thick Merv style frame will allow for more surface area and require less frequent replacement. Duct modifications to modify a 1” filter frame can be costly ($250.00 or more) but worth it in the long run.
High static pressure is like high blood pressure. Be good to yourself and to your furnace.