Question on cooling coils
 

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 ho****er
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

The Configuration you describe is not valid. For instance if the air off the
coil was 12 C with 50% bypass at 26 C the mixed air temp would be 19 C.
In addition a hot water coil could not be used by a reverse cycle heat
pump. So there is probably either a third coil or a damper
to shut off the air flow to one side of the coil
wrote in message
oups.com...
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 ho****er
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

wrote
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.

You opened the unit up while it was running?



My AC is a standard heatpump unit setup with one twist. The ho****er
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

wrote in message
oups.com...
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 ho****er
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

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

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

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.

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

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.

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.

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