I'm still trying to determine the real facts about the Aprilaire 5000 air cleaner, and other 4-5 inch media filters in general. After further discussion with our potential contractor for a furnace and A/C replacement, he explained to me why he doesn't like the Aprilaire 5000. He claims that it causes high static pressure in the system, so much so that it will dramatically shorten the life of the furnace. He said something like "we shoot for no more than 3" of static pressure in the entire HVAC system, but the Aprilaire 5000 starts out with 3" static pressure all by itself", and also said that this high SP will shorten the life of the equipment (Amana 2-stage variable speed furnace) dramatically. Needless to say, these kinds of statements concern me. However, they also seem a bit far-fetched from what I've read here and other places.

We would very much like the benefits of the AA 5000 if possible, as we have allergies and asthma in our home. He also commented on the electronic part of the AA 5000 creating ozone, which can be a problem for asthma sufferers. As you may remember from my previous post, this contractor is pushing Dynamic air filters. I'm not interested in those.

My bottom line on this company is that they seem to know the furnace and A/C equipment and would do a good install, but they seem pretty clueless on IAQ issues. At this point they are far and away the most promising of the contractors I've talked with, but still have weak areas (i.e. they think it strange to use a 2-stage stat with a 2-stage furnace, etc.) - those questions may be the subject of another post.

Can somebody shed some FACTUAL data on this filter situation for me? Aprilaire's documents sure don't support his allegations, but he claims to have seen a bunch of filters tested in a special blower arrangement that measured pressure drop or static pressure or some such, and the AA 5000 flunked big time. Of course the Dynamic passed with flying colors. HELP!!!