how do you keep air conditioning ductwork in the basement from sweating and dripping all over the floor ?

Answer 1

I hate to weigh in on an issue so thoroughly covered, but you may not be addressing the underlying cause. The primary reason for sweating ducts is not relative humidity or lack of insulation. If the sweating is new, or has increased substantially recently, your air flow has become obstructed, probably by loaded air filters or a dirty evaporator coil. if the problem is ongoing and long-term, it is likely that your ducts were undersized
when they were first installed.

The reason that it is not in your best interest to bury the problem under insulation and dehumidifiers is that improperly-sized or obstructed ducts are inefficient (therefore costly), breeders of mold and excess relative humidity, and will cause your equipment to fail prematurely.

I recommend that you hire an a/c company that has the proper equipment to test and balance your system prior to the cosmetic solutions. In the long run, this will more than pay for itself.
Good luck and God bless you.

Answer 2

Ductwork sweating is a very common problem that is caused by the cold metal duct coming into contact with warmer moist air.

To correct this, go to Lowes or Home Depot and buy blanket mineral fiber duct insulation. It will have a foil face and cost about $15 for a 15' roll 12" wide. Also buy the metal foil duct tape.

Wrap the insulation around the duct completely covering and sealing all exposed duct portions so that air cannot contact it from the outside. Seal this duct all the way back to the unit and to the whatever sleeve or boot it passes to or through.

Sweating is caused by the warm moisture laden air being cooled below it's dew point. If you prevent the air from touching the cool duct, you will NEVER have condensation.

God luck- you can do this and it will not be expensive. A pain but not expensive.

Not saying a dehumidifier is a bad idea but even what is normaly considered 'dry' air at 50% Rh will still cause condensate when it hits a 55 degree duct. SO a dehu really isn;t going to solve the sweating problem if you have poorly insualted ductwork.

Answer 3

You can buy some relled insulation and wrap the ductwork. The sweating is just condensation because of the temp difference of the metal ductwork and the air temp in the basement.

A dehumidifier may work, but insulation will work.

To wrap the duct measure the distance arount the outside of the duct, and cut the insualtion about 4 inches longer than that. wrap the insulation around the duct and about 4" should overlab, take this extra and pinch it together and staple it. Then go onto the next piece, and tape the pieces together at the seam.

Answer 4

Okidokey.... sweating air ducts are the result of condesnation of moisture in the air... against the cold ductwork itself.... you have 2 methods of resolving this, and frankly, I would use both.

First and easiest method is to install a dehumidifier in the basement.... the container on the dehumidifier will need to be empied regularly of course, so put it where you can get to it easily, heheheh. This will help REDUCE the moisture in the air, but it is unlikely to ELIMINATE all the moisture. Meaning your pipes will sweat less, but will continue to sweat.

Second method is a bit more work.... you need to insulate and SEAL the outer surface of the ductwork. Rolled insulation is handy for this, but I have seen foam board used successfully too. If you have square ducts, you may want to glue the foam board to the ductwork itself (use glue made for the foam board). Round duct is almost certainly going to need rolled insulation.

To use the Rolled insulation, or batten insulation, you need to wrap it around the ductwork... overlapping the insulation as you go. I prefer to use the batten strips, like you buy in the package to go in a standard wall.... not so much insulation to have to continually bring around the pipes, heheheh. Remember to overlap all the edges of the insulation. A strip of duct tape here and there, will help hold it in place, while you work. Oh.. .and don't 'pull' the insulation tight.... insulation works because it builds up an air barrier.... so, the fluffier the better.

Next, you need to SEAL the ductwork.... to do this, you need to wrap plastic over the insulation, and tape the seams. A good heavy plastic, say 6 mil thick, works very well as a moisture barrier. Just start at one end of the duct, and wrap the ductwork with the plastic...again, overlapping the seams of the plastic, just like you did with the insulation. When you are done wrapping, take a good quality duct tape, and seal the seams of the plastic.

Obviously, you do not want to turn off the air to work on the pipes, because this would make the rest of the home miserable.... so... install that de-humidifier, and put it to work... the following weekend, you can start wrapping the pipes... use towels or rags, to wipe off the moisture on pipe, as you are wrapping it with insulation. You could do this just by yourself, but an extra pair of hands will help a lot, and make the job go easier.

There are added benefits to taking the time, and expense of doing both of these things.... not only can you eliminate the dripping. By insulating the ductwork, you will have less temperature loss from your central unit, to the vents themselves... this gaurantees a more efficient heating and cooling system for your home. By eliminating the excess moisture in your basement... .you prevent all kinds of troubles, like mold... mildew... bad smells from those, and structural damage to the lumber in the home from having too high a moisture content.

I would use the insualation with the paper backing myself, just because it helps keep ME clean, as I install it. Wear gloves, and safety glasses, and a dust mask wouldnt hurt, to keep the fiberglass out of your lungs, as you work. Longsleeves will help keep your arms free of the fiberglass too.... IF you should happen to get any on you... rinse the area with cold water..... this will help close off the pores of the skin... open pores means the fiberglass can go in deeper, causing more itching and irritation... closed pores keeps the fiberglass on the surface, where you can wash it away.

Good Luck!

Answer 5

Buy a dehumidifier for the basement. The humidity in the air in your basement is condensing on the cold duct work causing it to sweat.

Answer 6

It is not a problem with the duct work itself but most probably a clog in the drain pipe that is supposed to lead the water collected in the drain pan (located under the evaporator unit) to the disposal.

Unclog the drain pipe and voila! the condensation around duct pipe would be gone.

Answer 7

1

Answer 8

Insulate your ductwork.