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Doug7852 03-31-2011 09:52 PM

furnace filter fit??
When I install a new filter I noticed that the rails where the filter sits (it is horizontal not vertical) are not flat between the corners. This allows the filter to not "seat" on the rails. It may be pulled down onto the rails once the air flow starts. Also on the side of the ductwork where the filter access door is there is no rail and the door doesn't seal against the front edge is the filter. It would seem that the air flow will take the path of least resistance around the edges and in front of the filter thus not passing most of the air flow through the filter. Am I being too anal about this or should I take steps to make sure the filter sits flatter on the rails and also provide a rail on the front of the duct?

how 03-31-2011 11:45 PM

It is mostly relevent to your tolerance to dust. If you have a medical condition related to breathing then maybe it would be worthwhile, but I doubt it will make any difference to your heating equipement.

thehvacguy 04-01-2011 02:52 AM

Do you have cooling too? You dont want to dirty your indoor coil too much...

Doug7852 04-01-2011 11:22 AM

I do have AC also.

Dust getting into the house has been a bit of an issue in the past. In certain parts of the house (one closet in particular) we get an accumulation of dust. We could possibly have some dust issues with some allergy type reactions (not a big issue).

From the replies to this point, I am getting the idea that keeping the air flow restricted to passing through the filter really isn't a big deal except allowing some unfiltered air to pass through the coil and then into the house. If you installed a system what would you do?

how 04-01-2011 11:45 AM

If dust is a deal for you and you are willing to put some effort into cleaning it 3 - 4 times a yaer, then an electronic air cleaner will give you some of the best ratings for removing dust while not restricting the air flow through the furnace. You'll need a bit of space in your return air plenum to fit it. Some people don't like the ozone it can produce but that can be dealt with by degrading it a bit to suit.
And remember that most of home's dust problems (unless you have dust producing besiness in the home) comes from a humidity level that is too dry. (Insufficient fresh air into the home).
