Question on cooling coils

[rnbeasley]

A question for the pros --

I live in an apartment and I've noticed that my AC hasn't been cooling well recently. The maintenance staff checked the freon level and said it's fine, but it's still not cooling well.

Tonight I decided to poke around inside the air handling unit to see what I could find. Inside is two sets of cooling coils arranged in an upside V arrangement. When I placed my hand on them while the AC was running I discoverd that one side of the V was was cold but the other set was not. It was at the ambient air temp and was not cooling at all.

My AC is a standard heatpump unit setup with one twist. The hotwater heater is attached to air handling unit via two hoses to provide backup heat (or primary heat if you prefer to heat with gas rather than electricity).

My question is should both sets of cooling coils be cooling or is one set of coils for AC and the other set for heating? Is the reason my AC isn't cooling very well because 50% of the cooling coils aren't working?

Thanks for you help.

Neal B. Richmond, VA

[SQLit]

Are the coils separate, not connected via the piping? you sort of indicate that they are. If so, I have not seen a dual coil setup in residential in more than 15 years. Way expensive. Since the Hot water is connected to one coil I am assuming that you have a hot coil and a cooling coil. If that is correct then it would be normal for one to be ambient and the other cold.

Periods of high humidity do cause an apparent loss in cooling. The unit can only do what it is designed to do. No most folks do not design for the extremes. Usually normal high temps and humidity.

Measure the return air temp and the closest supply air temp to the coil. ( the one that blows the hardest ). At the same time. There should be a difference of ~20 degrees F. If less than 10 F then call back the a/c guys boss and have him come up and check the unit.

WAG's from information supplied

[Stretch]

neal, Your coil is called an "A" coil, because it is shaped like a capital A without the horizontal bar. This is a normal coil for most manufacturers because a old style slab coil will not provide enough coil surface without having a very large cabinet. are you saying that one leg of the A is not getting cold? Or are you saying the ar entering side of both coils is cold while the lair leaving side is just cool?

Stretch

[rnbeasley]

Yes, one side of the A is cold and the other side is ambient temp and is not cooling at all. I think that side of the A is either damaged or clogged with trash because it's not the least bit cool to the touch.

[rnbeasley]

Sure. Just took the side panel off the air handler where the fan is located. Nothing holding on but a single screw.

[rnbeasley]

I'll have to check and see if I can find another coil used by the hot water. Now that I think about it, it doesn't make sense for both freon and hot water to be using the same cooling/heating coils. I'll check and see what I can find.

Thanks.

[rnbeasley]

I'll check and see what I can find. I'll trace the pipes in detail and try to determine what is connected to the heatpump and what is connected to the water heater.

Thanks.

[Dr. Hardcrab]

wrote

You opened the unit up while it was running?

[rnbeasley]

I think I figured it out. The hot water/aux heating unit has it's own flat coil in the top of the air handler above the blower and just below where the central air duct connects. Both of the hoses from the water heater attach to this coil.

The lower A-coil is for the heatpump only and is only working on one side of the A. The side that works gets cold very quickly when the unit comes on. The other side is clogged or damaged and has no coolant circulating. That side does not change temp at all when the unit is running.

Time to talk to my maintenance guy.

Thanks for the help. Neal B. Richmond, VA

[Paddlepop]