Air Filters
Tuesday, February 1st, 2011 at
5:46 pm
Tim Carter, of AsktheBuilder.com, tells us why using air filters in our homes is so important.
Tagged with: air • ask • builder • carter • disposable • dust • fibers • FILTER • filters • furnace • good • paper • pollen • pollutants • protection • tim
Filed under: Air Cleaner Videos
do not buy an electrostatic filter,they do not let enought airflow through.
That is not true. When clean, they do not cause a drop in static pressure that exceeds the normal limit of one-half inch. If they get clogged like any filter, then they can become problematic. All air filters must be kept clean.
ask the builder / do you say anything about how the pleated filter restrict air flow and that type filter will not work in all systems due to the airflow. I have seen these filters cause thee most problems in the a/c season due to the need for more airflow !!!!
Yes, you have to be careful with all filters. Any can clog causing low air flow.
no I mean that even before clogged they cause restriction
I believe the standard is one-half inch of static pressure. If the clean filter creates less than that, it is okay.
You’re right – 0.5″wc is the “target” TESP – this will allow 400 cfm/ton give or take 10% – just right! BUT exactly HOW is the homeowner supposed to verify that the new “high performance” air filter won’t reduce air flow and end up causing more problems than help?
Without a gauge, I suspect they should check the filter regularly and change it when they see visible dirt buildup. They should also follow all written instructions from the filter and HVAC equipment manufacturers.
what is the merve rating on the electrostatic filter?
I believe it’s the same as its coefficient of continuity.
In 5 years of cleaning electrostatics we’ve found the following – Electrostatic filters start up with about 25% higher resistance than standard pleated filters, but as they fill up they depth load while the pleated filter face loads. The result is, during the second half of the filter life, the electrostatic remains fairly constant in flow while the flow of the pleated is reduced significantly and quickly.
I want good filtration without excess restriction, the pleated filters in my unit are bowing when I remove them because they’re pulling so hard. Fiberglass filters are useless, should I upsize the cold air return from 20 x 25, or have it modified to hold a thicker filter, say 2″ to 4″ ??
Electrostatic & pleated filters are a death sentence to system performance beause they increase static press. which reduces air flow. This can cause a furnace to overheat and the A/C to freeze up. Unlerss the system was designed them Contact a quailfied contractor who understands airflow performance and static pressures. Upgrading to a high efficiency air filter without any other considerations is costly.
Correct. Dirty filters can dramatically increase static pressure.