Any A/C Guys on here?
 

Had a general question about Air Conditioners.

I have 2 units in my house and the house is about 5 years old.
I was having a problem with my air handlers in my attic sweating a lot during the summer months.

A friend advised me to stop using the high dollar air filters and start using the cheaper fiberglass ones to allow more air flow. He just advised changing them monthly, which I have been adhering to and this seemed to be working for a while.

One of my units started sweating again and the other is not. I change all the filters at the same time so I don't think that is the problem. Is there anything else I should be doing to maintain my air handlers? Any other problems that cause them to sweat like that?

well attic ventilation can affect it so make sure the openings and vents are still working correctly and not blocked by anything.

from your description I would think its probably just a dirty coil that needs cleaning but Freon levels could also be the cause.

you missed the spring checkup specials most companies run but I suggest you have both units inspected and get a guy to check the coils if they are dirty.

we will assume the units are original to the house so after 5 years its not to be expected but also not that uncommon for one or both units to need the cooling coils cleaned.

i have 38 years fixing a/c & htg units and for units to be sweating its going to be too much humidity in the attic from poor ventilation or the coils are getting too cold from lack of airflow which can be from being low on Freon, dirt blocking the coil, or dirty air filters.

many companies don't do the best job sealing up air leaks from the connecting boxes the unit attaches to so when you get a chance for cooler weather it will be good to get in the attic and caulk around any cracks or seams between the r/a box and the framing as well as around the unit anywhere there are openings that can let air in, just don't seal off any access panels but you can put the aluminum tape over them to seal it up. if your units have r/a closets for the air to get up to the units in the attic then you should try to get inside then and seal up any cracks or openings where it can suck air in from the walls rather then the filter. its very common for most of the dust and dirt units collect is from indirect sources due to non-filtered air being pulled in from leaks in the r/a after the filter.

the ductwork side is the plenum box and not as critical to seal up but its easy to find air leaks because you can feel the air coming out when its running. sealing these leaks just helps get 100% of your conditioned air going into the house and not leaking out into the attic.

for outside units keep the grass clear from them and don't put bushes around them, this can block free air getting to the unit and makes them work harder and run hotter and its a good idea to turn the units off when cutting grass near them so they don't vaccum up the flying grass clippings and of course never cut so the grass goes in the direction of the units for the same reason to keep them clean not to mention if the mower kicks out a hard object it can pierce the coil and the unit will be ruined so a single rock can cost you over a $1,000 if you are unlucky

Is it the plenem that is sweating or your airhandler? Either way you can wrap them with insulation and it would help. As far as the filters as long as you change them every month. That shouldn't matter, if you go with the cheep filters in three or four years you'll have to get your coils cleaned.

It's the bottom of the Air Handler unit that is sweating... but only 1 of the 2 units is sweating... seems if it was humidity or air flow in the attic that both units would be affected. There is a float switch in the drip pans to kill the unit if the water doesn't drain... It's just draining out the overflow but it shouldn't be sweating that bad right?

Ya I agree with kekar probably a dirty coil. If you need someone to check it. I am a certified technician.

I'm about ready to have you come mess with mine! Will give you a call soon.

Matt's a good dude

if its electric heat then that is where the coil is located and its only got like 1/2" of thin insulation between the coil and the metal casing so it gets cool to the touch normally but if the coil is dirty or developing ice it gets very cold and the outside casing of the unit will get cold enough to sweat just like your beer can does. under normal conditions the attic heat warms it enough so it doesn't sweat