Air conditioning/water help

In article , stryped wrote: [,,,]

Probably due to high humidity condensing on the outside of the ducts. I'm guessing that your crawl space has no vapor barrier on top of the soil, and no foundation vents either. Now you know why it's a good idea to have both.

Reduce humidity and ventilate.

stryped fired this volley in news:78b2cd5b-73c1- snipped-for-privacy@r27g2000yqb.googlegroups.com:

The duct work? Or do you mean the register itself?

If the ductwork is wet, you have a really UGLY and expensive job ahead.

If it's the register...I would first guess that the AC is oversized for the application, and isn't running long enough per cycle to dehumdify properly, or that there's an _extreme_ moisture source inside that is keeping the humidity high despite the AC.

When registers get cold enough to condense moisture, they're either running too cold, or the humidity in the space is too high. Either way, it sounds like 1)too large a unit for the space, 2) insufficient airflow, resulting in too cold air, or 3) a bad humidity source in the house that is preventing the AC from removing enough of it to keep from condensing at the outlet air temperature.

No harm intended here, Styped: You're out of your league. Hire a pro to diagnose the problem.

LLoyd

It is generally a good idea to wash out the condenser coil (outside) every year with a concentrated spray from a garden hose, at least. That probably isn't related to the wet ducts, but could be related to higher electric bills.

You may also need to clean the evaporator coil, that can be harder to do without making a huge mess. If it is clogged with dust, it can slow airflow, and cause the smaller volume of air to get colder than it should, leading to condensation in the ducts. Also, of course, make sure the air filter is clean, and the slot where you insert it is not leaking a lot of air. Check the insulation on the ducts, it may be coming loose. If you ducts are not insulated, then crawl space systems will surely get condensation and poor efficiency. You might do well to wrap insulation batts around it.

Jon

There are vents in my crawlspace and a vapor barrier on the ground. AT night the thermostat is set at 71-72. Could thi sbe a problem?

Once the duct work is wet does it have to be replaced?

It should dry out OK. The real problem is if it gets wet and stays wet for long enough, then you could have mold starting to grow. Is it possible it always got wet and you just never noticed it? Another possibility is diminished air flow through the system. That would mean you are getting less air out, but the air is much colder, dropping the temp of the outside of the ducts more so that when it's humid condensation occurs.

Check air flow, filters, blower speed, A coil for blockage, all vents fully open, etc.

As for system life, from what I've seen posted here the consensus seems to be that systems from decades ago generally lasted 20-25 years. Newer systems seem to be more like 15-20.

There is also the 30% Fed tax credit for new high efficiency systems that expires this year. That combined with possible state, utility, manf rebates etc can greatly lower the cost of a new system.

I just this week had a related problem with our a/c system. The funace is on the main floor of the house and the house has a full basement. The A/C has a lateral drain line across the ceiling of the basement that goes over about 10 feet and then down to a sump pump. That lateral line plugged up with crud and most of the water backed up to a loose connection where it leaked out to the basement floor. I cleaned the line with compressed air to solve the problem. Our system is 18 years old. We have had a freon leak fixed once and and a cooling fan on the condenser replaced once. If the compressor died, we'd probably replace the system, but not until then.

Pete Stanaitis

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stryped wrote:

Nothing should be wet, get a pro out. Hopefully its a new issue or the water damage will cost you alot of money

That has what to do with the duct work in the crawlspace being wet? A condensate drain issue results in what you had, water on the floor, not wet ducts all over the crawlspace.

Wow, that will sure explain your high utility bills. We set ours about

If it is not insulated, no. If it is insulated, and the insulation has started to grow mold, yet! If no mold, then you need to get it dried out and see what can be done to keep it dry.

Jon

My advice is to do a complete check of the condensate pan and drain system. Problems with that are the most common reason for water further down. Just because it looks like it is working does no tmean it is. Check all of it for clogging. Start by taking the access panel off the A coil and see if the water is draining out of there properly.

I just found my metal register boxes in some spots are wet with condensation. I can feel s small air leak with my hand at the corner of this box but cant seem to tape it or anythign where I cant feel it. Could an air leak cause this?

While I am on the subject, is there any beneift / detrimate to have a self contained unit verus a split system?

stryped fired this volley in news:5e9b7f49-4b3f-480c- snipped-for-privacy@p22g2000pre.googlegroups.com:

Yes, Stryped. An air leak could cause you to feel a small air leak with your hand.

LLoyd

I mean, could a small air leak such as this somehow cause condensation on the subfloor?

What speed is the fan running in the air handler? Don't assume it was installed correctly, if high speed, it may be blowing condensate (spitting) out to the airducts. Also check condensate drain line. I believe you indicated crawl space had ground vapor barrier, but there were airvents to space. During summer cooling, these would be wise to close off. I don't know where your located, but what is the typical outdoor humidity on a summer day. This time of the year in Iowa, we run with dew points close to ambient. How is the return air piped into this air handler? Is it leaking (sucking air from the crawl space)? ignator

What speed is the fan running in the air handler? Don't assume it was installed correctly, if high speed, it may be blowing condensate (spitting) out to the airducts. Also check condensate drain line. I believe you indicated crawl space had ground vapor barrier, but there were airvents to space. During summer cooling, these would be wise to close off. I don't know where your located, but what is the typical outdoor humidity on a summer day. This time of the year in Iowa, we run with dew points close to ambient. How is the return air piped into this air handler? Is it leaking (sucking air from the crawl space)? ignator

Checked condensate drain line. It is ok. I live in the south where 90% plus humidity is common. SHould I close the vents?

Return air uses flex duxt to the inside of the house.

My metal box registers are sweating greatly. What I am finding is they sweat into the flexible duct insulation. I replace some insulation a few days ago and the tip of the insulation that contacts the metal box is already wet. Would it be feasable to take fiberglass batts and wrap around the metal duct box that attaches to the subfloor?