New Installation Questions

[d6veteran]

I just moved to Iowa and bought an old ranch home. The AC is very old (the unit that sits outside says 1964 on it) and my home inspector said to replace it before Spring. The duct work and blower is in the attic. I have radiant heat (works great) so the duct work is all for the AC.

I've already decided to go with an R410A unit.

I have had two bids so far.

The first guy gave me the impression he did not want to work in the attic (he did not even go up there) and he spent 2 hours trying to convince me to put the unit and duct work in the basement. He also told me that R22 was not harming the ozone and that R410A units are known to leak.

The second guy went straight up to the attic and did not even mention putting it down in the basement.

Here are my questions:

1) Is there any reason to move the AC to the basement?

2) My current duct work has insulation on the INSIDE of the ducts. That insulation is flaking and coming through the vents. I want to replace those ducts so that the insulation is on the outside. The contractor said he would replace the duct work, but he didn't seem concerned about the insulation being on the inside. Does it make sense to replace this old duct work?

3) My current vents show rust. The other day is was about 40 degrees and humid and I noticed water dripping (slowly) from some of the vents. The contractor who went up in the attic pointed out that my feeder ducts, which have the insulation on the OUTSIDE, have the insulation coming off in places and said this might be causing condensation problems. When I mentioned the rust and moisture issues to the contractor who was pushing for a basement install, he then jumped on that issue and said by putting the duct work in the basement you eliminate moisture problems. Are the moisture problems an attic problem or a duct problem?

Money is not an issue (within reason). What I want is efficient AC with no moisture problems and clean ducts.

Any comments appreciated.

Thanks.

[t527ed]

go back in with a new TIGHT attic system.

[contactor]

Sweating supply registers indicate low airflow. I don't believe in having insulation inside of ducts for the very reason your decribing, (insulation falling apart), not to mention you are breathing that. Its falling apart because of condensation too. A properly designed system w/ proper airflow will not condense water anywhere but at the indoor coil as designed.
Go with an attic system for AC for best overall efficiency. Make sure all ductwork is sealed airtight w/ mastic or other means, and insulate externally w/R-8 min.
Insulate attic if it hasn,t been blown to meet an R-38 afterwords. Have contractor due a man. J heat load, and man. D for proper size ductwork.;)

[icyflame]

If you go with the basement deal then you will be left with holes in your ceiling. Your best move is to go with contractor #2 with a new duct system properly sized and sealed. :)

[deq1269]

I would definetly stay with the attic. Have the ducts replaced and sized right by a professional. Also, consider having a heat pump put in. It doesnt cost that much more and will act as a backup in case your other system goes down.

[dash]

Cooling only ducts ,in the attic,in cold climates condense moisture inside when the humidity is higher.

Replace IF the insulation is breaking down.

Since you want to add ceiling lights ,they could cover the holes left by moving the ducts to the basement.Ducts in the basement will be not be exposed to the extreme heat like the attic during cooling,and they won't condense moisture in the winter.

[trane]

I agree with Dash,

Any advantage that A/C will work better in the attic because cold air falls is most times eliminated by the heat gain in the duct system. It gets extremely hot in some attics on older homes and even newer ones not ventilated correctly. You don't say if the basement is conditioned but even if its not the heat gain would be far less.

I go to the attic only if there is not another way. If you do have the system installed in the attic check what the R value is on the insulation they will use and what safties they are installing to prevent water damage should the drain become plugged.

[d6veteran]

Thanks for all the replies.

I'm partial to staying in the attic for two reasons:

1) I want to remodel the basement and use that space (our home has 1200 sq feet on the main level - so getting some extra space in the basement was the inent when I purchased). The main duct work in the basement would have to run against the joist and the ceiling is already low.

2) I hate floor vents. ;)

It sounds like I really need to be on top of making sure the duct work is properly sealed and insulated.

I'm going to call the second contractor and find a third and go from there.

Thanks again.

[finest]

A properly installed and insulated attic system will work great,i would suggest completely replacing the entire system.