Filtrete Ultra Allergen Reduction Filter, 1500 MPR, 14-Inch by 30-Inch by 1-Inch, 6-Pack

Try the Advanced Allergen filter if you have allergies or pets
My house uses forced air for heating. The disadvantage of such a system is that it distributes the dust in the air everywhere in the house. However, it is supposed to be possible to filter out the dust. Over the years, I have steadily increased the quality of the filter that I use for my forced air heating system. However, until now I have not noticed any obvious difference in my allergic reactions that seem to start with the heating season.

There are two cats in my house. I have read that cat dander, tiny flakes of cat skin shed by the cats, is five times smaller than household dust particles. It stays in the air much longer than ordinary dust before it settles. Because of its small size it requires a more efficient filter to get it out of the air.

Until this year, I have used of variety of filters with mixed results. However, this year, I started using the 3M Advanced Allergen Filters, the ones in the blue wrapper. These have a 3M Microparticle Performance...

Too high a restriction, the house got cold...
I found this Amazon product page while looking for information on furnace problems and this filter.

We've been using the red "micro" Filtrete filters for years. This was our first try with the purple "Ultra" filters. I tried one in December, and removed it today (January 3, 2010).

It cut our heating ability by at least 40%!

With the red Filtrete, we have at least 92 degrees of heating ability: if we set the thermostat at 72, the house maintains 72, even when the outside "ambient" temperature (the average of the day's low and high) is -20 degrees F.

Yesterday and today, we lost the ability to maintain temperature. On a day with an average temperature of 10 degrees F (low of 5, high of 15) the house dropped to 65 degrees. So, instead of being able to heat the house to at least 90 degrees above the outside temperature, we are down to only 55 degrees.

The FAQ on the 3M site glosses over this problem.

"Do I have to worry...

Fine; but overpriced
Below are some rating information on 3M filters.

The media fibers are polypropylene and polyolefin plastic to include cardboard frames.

All our filters will remove particles that measure .3-10 microns.

Performance, MERV Ratings and pressure drop:

Maximum Allergen 1700

1-10 microns - 93%
MERV 12
pressure drop .20

Ultra Allergen 1250 *** (Purple)

1-10 microns - 90%
MERV 11
pressure drop .18

Allergen Reduction*** (Teal)

1-10 Microns- 85%
MERV 11
pressure drop .23

Micro Allergen 1000*** (Red)

1-10 microns - 80%
MERV 11
pressure drop .21

Dust & Pollen 600*** (Green)

1-10 microns - 70%
MERV 8
pressure drop .14

Dust Reduction 300

1-10 microns - 60%
MERV 7
pressure drop .15

As clean filters, the product is not restrictive to air flow. Filters will become...

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