Furnace filters are rated by their minimum efficiency reporting value or merv the higher the rating the more efficient the filter is at trapping airborne particles.
High velocity air flow furnace filter.
This product is ideal for high velocity hvac systems and it lasts up to three months.
They used 492 feet per minute fpm as the face velocity because that s what the ashrae filter standard 52 2 calls for.
Furnace manufacturers prefer the traditional spun fiberglass ac filters merv 2.
With that face velocity and those dimensions the air flow rate is 1 367 cubic feet per minute cfm.
Filberbuy has several different types of well made furnace filters.
3m filtrete filters are an economical upgrade from cheap one month filters.
Freeze the air conditioner coil.
Most residential filters range from 4 to 12.
The numerical range is from.
Maintaining the furnace manufacturer s specified airflow is critical to achieving energy efficiency and maximum life from the blower motor and heat exchanger.
A minimum merv 0f 4 is needed to protect the furnace a good value to help indoor air quality is 8 9 this blocks more with the max 16.
See my article on the continuity equation for more on this.
Reduce the air flow.
The 3m filtrete dust pollen furnace filter is an electrostatically charged furnace filter ideal for high velocity hvac systems.
To summarize a high merv filter can.
These filter out enough of the large particles to protect the furnace while providing maximum airflow.
Add resistance to the air flow.
The higher the merv number the more expensive they tend to be.
Purifies air by capturing a high percentage of household air particles including those at 0 3 microns.
This highly rated filter has the highest fpr possible and comes in a wide range of sizes fitting most all furnaces.
It has an electrostatically charged design capable of attracting and trapping larger allergens.
Flow rate equals area times velocity.
Increase the pressure in the duct system.
That s only a benefit as long as the air flow isn t so low that it turns the condensate to ice.
Increase the energy use of the system.