Solution to floor air return getting dirty quickly
#1
07-12-07, 10:28 AM
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Solution to floor air return getting dirty quickly
Howdy-
When previous owners of the house converted the gas furnace to a heat pump, they left the rectangular hole in the center of the floor of the house as the air return. Many houses in my neighborhood had the return moved to a wall nearby.
The result? I have a 20*30 floor grate sitting over the box that houses the air return and filter. The air return duct is only 12", I think. The problem is that regular foot traffic puts a lot of dirt/dust down onto the filter, thus making it full/clogged quicker than if it were on the wall.
My proposed solution? As the air return duct is on one side of the 20*30 box, I was thinking about putting cardboard underneath the grate directly above the air return. This would partially block the air return but it's big enough that the air passing through on the other side of the grate (that's not over ther filter) would still be adequate and perhaps less dirt would fall directly onto the filter.
Will this work or will it significantly affect the flow of return air into the system?
Of course, take a look at the diagram here to see what I mean.
http://s157.photobucket.com/albums/t65/chrisatunc/2453%20Derby/?action=view¤t=Floorairreturn.jpg
Thanks,
Chris
When previous owners of the house converted the gas furnace to a heat pump, they left the rectangular hole in the center of the floor of the house as the air return. Many houses in my neighborhood had the return moved to a wall nearby.
The result? I have a 20*30 floor grate sitting over the box that houses the air return and filter. The air return duct is only 12", I think. The problem is that regular foot traffic puts a lot of dirt/dust down onto the filter, thus making it full/clogged quicker than if it were on the wall.
My proposed solution? As the air return duct is on one side of the 20*30 box, I was thinking about putting cardboard underneath the grate directly above the air return. This would partially block the air return but it's big enough that the air passing through on the other side of the grate (that's not over ther filter) would still be adequate and perhaps less dirt would fall directly onto the filter.
Will this work or will it significantly affect the flow of return air into the system?
Of course, take a look at the diagram here to see what I mean.
http://s157.photobucket.com/albums/t65/chrisatunc/2453%20Derby/?action=view¤t=Floorairreturn.jpg
Thanks,
Chris
#3
07-13-07, 07:33 AM
Join Date: Apr 2005
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Can I get a second opinion, anyone?
Airman, you didn't explain details of why this is a bad idea. My logic is that the airflow won't be a unrestricted as before but the altered air path will still have the same volume as the volume of the air duct. My plans do, in effect, introduce 2 90-degree bends in the flow.
Second, it gets dirty in a week or two. Otherwise, I'd do your vacuum-once-a-month suggestion and be good with it. Also, if I were going to move the return then I wouldn't posting about how to deal with my current situation ;-)
-Chris
Airman, you didn't explain details of why this is a bad idea. My logic is that the airflow won't be a unrestricted as before but the altered air path will still have the same volume as the volume of the air duct. My plans do, in effect, introduce 2 90-degree bends in the flow.
Second, it gets dirty in a week or two. Otherwise, I'd do your vacuum-once-a-month suggestion and be good with it. Also, if I were going to move the return then I wouldn't posting about how to deal with my current situation ;-)
-Chris
#4
07-14-07, 03:35 PM
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Not a good ideal... I don't know how deep the return box is, but you are going from an easy air flow right down into the filter to air flow rushing into a gap that is 5"? and only half the filter is going to be dirty. Also with the narrow path, going to get more air "rush" sound.
I would advise to have the return moved to another area with less foot traffic.
I would advise to have the return moved to another area with less foot traffic.
#5
08-01-07, 12:51 PM
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I've done it-if the size of the return duct is limited to, say, 100 sq inches, it is meaningless to have a grate that supplies 200 inches. I would make sure, when taking the grate louvers into account (usually 20-25% drop for metal grates-much more for wood) that you still have slightly more grate free area then the duct can support, but you don't have to have double or triple the free area. You don't want the grate to restrict airflow at all-thats it. Having a grate that can support 500 sq. inches of airflow or whatever doesn't do anything if the duct free area is only 100 sq inches.....the furnace will still only get 100 sq. inches of air.
Nick
Nick
#6
08-01-07, 03:00 PM
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I also agree that it is not a good idea to block the return.
Because a filter offers some restriction in many cases it should be bigger than the return duct.
Would the joist space that contains the duct continue on to a wall where you could relocate the inlet.
Plus, does the furnace or ductwork allow the installation of a filter rack?
Why was the filter put there in the first place?
Because a filter offers some restriction in many cases it should be bigger than the return duct.
Would the joist space that contains the duct continue on to a wall where you could relocate the inlet.
Plus, does the furnace or ductwork allow the installation of a filter rack?
Why was the filter put there in the first place?
