Help w/cold air returns

[collinn]

All of a sudden our cold air returns don't seem to be working. The reason I know is the covers are clean as a whistle and I have an unusual amount of dust and debris on surfaces and hanging on walls and cabinets a la static cling. We live in the country on a dirt road and the amount of dust has always been bad, but I can't understand why the covers of all our returns are so clean and everything else is not. Didn't used to be that way. What could be causing this?

[dash]

1.Type of duct?

2.Type of filter?

3.Where are the returns located?

4.Model of equipment involved?

5.Where is the return duct located?Attic,crawl space,etc.

6.Do you feel air movement at the returns??

[collinn]

Uh, don't laugh - I'm not a professional. The ducting is metal, in the wall going from living area to unfinished
basement where our furace is located. We have a return in each of two bedrooms and one really large one in the living room. (1200 square feet upstairs - open floor plan). No, I no longer feel any air movement at the returns, but I used to. Our furnace man said that our blower was rather large for our needs, so he also cut a return on the unit itself which IS showing dirt and air movement can be felt. Since our dust is such a problem we have been using the 3M filters, but changing them every week because they are so dirty. We have a Janitrol. Now that I'm writing this out - maybe we should cover up the return on the unit itself to see if that will draw more air from upstairs ???

[tinknocker service tech]

i live on a dirt road also and the dust level is terrible
replaced my return duct because it was full of dust and the filter was at the unit. i put in a filter grille and new duts and it is fine
just for exanple only. if the blower is working right and the reture grilles are not pulling like they should then maybe you need to have your ducts cleaned
call a duct cleaning co. and have them looked at and get a price from them. dust can collect in the duct and biuld up and cut back on the flo

[markco]

Originally posted by collinn
Our furnace man said that our blower was rather large for our needs, so he also cut a return on the unit itself

Bad idea. Now you're pulling in musty basement air, and circulating it through the house. Also, cutting a return into the ductwork near the furnace could cause drafting problems with the furnace and water heater flues.

[rclaoac]

Markco is completely right, you are pulling in dusty air from your unfinished basement. If the return ductwork was improperly sized to begin with, it should be resized and replaced along with the correct sized return registers. It would be a good idea to install return grills with filter racks, that will keep your ductwork clean and makes filter replacement more convienent.

[pstu]

I have been told that a fresh-air inlet, pulling *filtered* outside air into the return, might help reduce dust in the house. The concept is that less outside air will be pulled into the house through random cracks and other openings. That inlet will be actively pumping maybe 75 cfm air into the house, resulting in a tiny positive pressure -- the indoors air will tend to flow outward.

It's hard to say just where is the source of your dust but perhaps this idea will help. And it will probably not hurt your energy bills very much if it tends to displace existing air pulled in thru random openings. Am thinking about doing this on my own house but have not yet.

Best of luck -- P.Student

[oilie hands]

i thought the first thing a serviceman was taught was , never draw return air from the room the unit was in.

[rango]

I live in 100+ yrsr old leaky house and would be interested in whether that works. The air exchange, I mean.