hvac questions

[coachshot99]

I just bought a house in the Tampa area. It has a 5 yearl old Trane system. Supposedly, a pretty nice system (according to the AC guy that i trust). Variable speed, new media filter on the air handler etc...

Anyhow, I moved in in May and the system ran alot through the summer. It's hot in Tampa, in case you were wondering.

But now that it has cooled down a little, the system isn't running nearly as much (hooray!) But when the system is off, i notice a musty smell coming from the lone return grate in the house. It is in a hallway and when the system isn't running, there is a distinct musty smell that is coming from the return.

My question is this... Can I put a filter at the return even though there is a large media filter in the handler (located in the garage) or will this restrict air-flow.

Also, what can I do to clean the return duct... It appears to have quite a bit of dust in it. Which makes sense as it has been unfiltered for 5 years...

I also have a biocide chamber (UV Light) installed in my air handler just below the coils, so I am not too worried about the air coming through the supply vents. But I am concerned about the air that is coming back through the return vent when the system is off.

Suggestions???

[tinnermitch]

What's up! your not supposed to put a secondary filter in a system, however I've seen it done as long as it is a cheap disposable one that lets alot of air pass. Sounds like a duct cleaning would not be a bad idea for you. its not that expensive and some of them do work. Some duct cleaning companies even have a disinfectant spray to help you out.

[beenthere]

No, don't put in a second air filter. It will restrict air flow, and make the blower work harder. Have your tech check out what the source of the odor is. And proceed from there.

[dash]

No to a second filter,unless you have a Pro test the ESP(resistance to air flow) of the duct system.

UVC light will not treat the air,when the system is runnig,air is moving too fast ,so not enough exposure time.

Typically they are install above the coil,in your area,maybe it's below the coil to try and treat the smell.

[beenthere]

Don't post the same question multiple times in different, or the same forum. Thank you.

I deleted your other 2.