Heat Pump guys: dripping evaporator coil

[MacLawn]

Our heat pump evaporator coil just won't drip properly into the drip pan! Ever since we had a new 13 SEER Carrier two stage, Puron, multiple speed unit put in in '03, the thing has dripped condensate! They even replaced it one time. I had it serviced yesterday. Man cleaned outside unit, sprayed some cleaner on the coil, still dripping. Heat pump man is coming back Tuesday. Anything I need to ask him, or tell him about what's happening?

 

[techman]

Level ?
Too high airflow
Pan not properly installed

 

[MacLawn]

Thanks tech. Since its been worked on at least three times for the same issue, plus replaced one time, I think it's level, etc. The service man who came yesterday told me his had dripped like that too. Seems it's a very common problem. The coils just depend on surface water tension to flow down the coils and into the drip pan.

 

[hosspuller]

A few thoughts. If your air flow is too high, the condensate will be carried over instead of flowing down. On the other end, if your filters and ductwork are too restrictive, it creates too much suction. Then the water overflows the pan instead of flowing out the drain. Speaking of drain... does your drain have a trap in it? Without a trap and enough fall... it won't drain.

 

[boggen]

boy oh boy.... i had some crazy issue a while back.... i thought my A/C duct work had a mouse or snake or some other animal in it. every once in a while i would hear a "bang" or a "scratch"

finally tracked it down to the "drain hose" hooked up to the pan below the coils. "air" was being sucked in and up the hose, and then at times being pushed out of the hose. result was i got noise's going through out my house.

i ended up doing a P trap basically. i ran the hose down to the floor, then up over a 2x4, then back down into the basement floor drain. once i had hose how i wanted it. i took a glass of water and funnel and partially filled hose. then put hose back down. and BAM! instant change to the system and never had issue since.

to note it, i did try a couple different setups, 2x4 on edge worked as min. i most likely should of created a larger P trap. having hose go down to floor then 8 inches up, then back down to the drain.

 

[Tractor Seabee]

The construction and location trap in the drain line is critical. The installation manual shows exactly how it is to be done and there is not much tolerence. The air pressures discussed earlier are a contributing factor also. In my AC tech days that was the first thing we checked when solving your complaint. There are AC Techs and then there are AC Techs.

Ron

 

[Bird]

My drain line (PVC) goes down in a wall behind the kitchen sink, then a hose to the drain under the sink. That PVC has about a 6" vertical pipe a very short distance from the A/C unit, into which I pour a little bleach about a once a month to make sure no algae grows in the line. There is a removable cap for that vertical pipe, but I found that, if it's capped, the sink P-trap does a lot of gurgling when the A/C is running. I can either leave the cap off the vertical pipe or put a stopper in the sink to prevent the gurgling. I leave the cap off.

 

[Tractor Seabee]

Bird, You may have found your problem. Coil drains are required to drain to open atmosphere. The normally drain into a floor drain with an air gap or to the outside. You do not indicate if there is a trap or not or I missed it. The trap is essential. It must hold enough water to overcome the static pressure in the fan housing or it will not drain. Again; you need the manufacturer's recommendations on how to run the drain line and the trap dimensions.

Ron

 

[MacLawn]

Ok, here's looking UP at the evaporator coil. You can see the black drip pan. The drain pipes, P trap, drip pan is all good. My problem is the condensate does not slide all the way down the coil, but drips onto the floor beneath (I have rubber mat to catch condensate). Surface tension. Seems to me lack of surface tension is the problem (wha' do I know?).

 

[MacLawn]

Oh, and thanks a lot boys, for trying to help. I'll keep y'all posted on what happens when the service man come July 21, 2015 (dating this rascal for future folks who might search this issue).