Yucky Ducts

[jeffw_00]

Thanks t527 - although, It's a lot of ductwork to wrap - since the flexes are probably toast, can they just install "double-wrapped" duct? (maybe I should go to rigid duct with a 'double' wrap - is there such a thing?)

What about the actual A/C unit - should that be wrapped? I mean, do I have to make sure -everything- is double-wrapped?

What sort of cycle for the blower? When I run the blower in the winter (when it's below freezing outside) it makes the house kind of drafty....

still - this is having the ring of truth to it....
thanks again
/j

[dash]

Run it on the lowest cfm.

Not sure about the cycles as we don't have that issue here.

[mchild]

Thanks t527 - although, It's a lot of ductwork to wrap - since the flexes are probably toast, can they just install "double-wrapped" duct? (maybe I should go to rigid duct with a 'double' wrap - is there such a thing?)

What about the actual A/C unit - should that be wrapped? I mean, do I have to make sure -everything- is double-wrapped?

What sort of cycle for the blower? When I run the blower in the winter (when it's below freezing outside) it makes the house kind of drafty....

still - this is having the ring of truth to it....
thanks again
/j

You can special order R10 insulated flex in sizes from 3" - 20" from: www.ancoproductsinc.com

[jeffw_00]

So you guys have me thinking that I what I need to do is
1) replace supply flex with heavily-insulated flex
2) "clean out" any mold in main supply trunk (not sure how this is done, but contractor should know?)
3) double-wrap main supply trunk
no work on returns - filter will keep stuff in returns from passing into supply

but I had my semi-annual checkup with my allergist (Senior guy at MassGeneral in Boston) yesterday. He said "sometime this winter, when it's really cold, turn off your humidifier for a day or two, and the dry air will kill all the mold. No need to replace anything".

So now I'm really confused 8-}

Still - does my original plan (nothwithstanding finding another cause when the work is done) make sense?

/j

[beenthere]

Your ducts in the attic, will always have a high RH then the house.

So if your house is at 20%RH, the ducts in the attic could be 55%RH.

Replacement of flex sounds good.

I would also put a block of sometime in the return grille, and stop the flow of air from going through the ducts in the attic.

[jeffw_00]

Hi BT - thanks - but there are actually 6 returns - although I suspect the problem is humidity directly rising into the supply ducts (as the blower doesn't run in the winter). I thought about closing all the supply registers in the winter, except a couple aren't adjustable or can't be easily reached (one is 12' up a sheer wall). None of the returns have adjustable registers, and none of the dampers are at the register, they're all at the taps from the supply trunk.

If it's simply a matter of killing airflow in the winter, we could put a damper at the main return (or simply wrap the spacegard filter in plastic and slide it back in). But I think I would have to somehow isolate all feeds/returns and that's a lot of things to block.

/j

[beenthere]

It can be a lot of work.

But thats how the moisture gets in the ducts. Just natural air convection.

[beenthere]

It can be a lot of work.

But thats how the moisture gets in the ducts. Just natural air convection.

[Daltex]

I'm not a pro so this is just a thought.

Could you have the bad flex run replaced and while the contractor is there have him check the main? You could just have an isolated area due to the bad DIY fan install. If the area of contamination is isolated to the one run then you may be in luck. If the whole supply is contaminated you have months to find a good contractor to solve the problem WITH you.

Does anyone else in your area have an AC only system like yours? May ask contractors in area if they do this and what they do to prevent the condensation in the winter.

If you could add strips to your AH you could run it enough to keep the condensation out?

[Daltex]

Forgot. Are you running the blower for the AC on auto? You probably already know that leaving it running after the condenser stops adds moisture to the ducts.

[jeffw_00]

HI guys - sorry for the late response, I didn't get the email notifications..

BT - I agree, but which is more painful - dampers at all the registers (that won't work completely), or insulating the duct system (so there's no condensation)? I'm actually not sure.

daltex - that what I'd like to do, but still trying to find a contractor who will, as you say, work -with- me, rather than just blindly replace the ductwork.

I do run the fan 24/7 from april to oct, improves my allergies.... But it's a "smart" evolution system so it does run a drying cycle after every cooling cycle
/j

[beenthere]

Flip of the quarter.

[jeffw_00]

ok - will leave it to the contractor's choice