Advice on Replacing ADP Coil

[CoolinSD]

I have a two story home in San Diego with separate AC units for the downstairs and upstairs. I recently had a local firm come out and tune-up the AC units in preparation for the summer. They found the upstairs unit was very low on Freon. The unit is located in the attic. When the technician went in the attic he detected a leak in the coil. The coil is from 1997, so it has lasted a pretty long time. I understand new coils are made out of aluminum and are much less prone to leaks (not that this one did not last a long time). Here is the info on the current leaking coil:

ADP - Cased Coil Evaporator
Model: HA04242C210B252280
Refrigerant: HCFC-22
Test Pressure: 350 PSI

From their Literature I believe this is the translation of what the Model number means:

Model:
H = Cabinet Color = Embossed Galvanized Steel
A04 = Slab Number
2 = Metering Device = piston
42 = Size 42
C = Cabinet Depth = 20.50"
210 = Width = 21.00"
B = Cabinet Upper Notch = 0.75" standard
25 = Cabinet Height = 25.50"
22 = Product Code = left-hand multiposition
80 = Florator Piston Size = 42,000 BTUH

I highly doubt that this exact coil is still being manufactured. I do not want to have to change out my whole system, so I want a coil that will run using the HCFC-22 coolant. Can someone suggest some makes and models of coils that I could use that would be compatible with my current system?

Also, how long should it take to install the new coil?

Could they somehow capture the coolant that is still in the system or would we need to refill it from scratch?

Please let me know if you have any questions.

I don't think I am supposed to ask price questions on the forum. Any guidance you can give me on cost for this type of repair would be appreciated.

Thanks!!

[Bazooka Joe]

Just about every manufacture makes cased coils, ADP is no exception. At nearly 20 years old, outdoor unit breakage certainly is a possibility in the near future unless you have a newer OD unit.

Yes they can pump the refrigerant into the outdoor to store it if your OD unit has shut off type service valves.

[Mr Bill]

Just about every manufacture makes cased coils, ADP is no exception. At nearly 20 years old, outdoor unit breakage certainly is a possibility in the near future unless you have a newer OD unit.

Yes they can pump the refrigerant into the outdoor to store it if your OD unit has shut off type service valves.

90 million folks out of work, I see this as a trend, we should get use to this, can you say thank you Big O..

[BaldLoonie]

Look for an HG coil, they are aluminum. The HE is more common, it has copper tube though rare to find one leaking. Your dealer should be able to pick one out based on what size A/C and what he can get.

[CoolinSD]

Hello,

Thank you for your comments. I had a second contractor come out and run tests. Unlike the first, he saw intermittent leaks in the evaporator coil. He said it could be because the unit is low on Freon (estimated two pounds plus) or that the unit has developed pinhole leaks. He gave me three options. I know we are not supposed to discuss prices, but I am going to list the relative price of the three options.

1) refill the unit with Freon and see how well it works this summer
2) run a high pressure nitrogen test for leaks at a cost of about 3.5x option #1. This may or may not definitively identify the leak source. I see little value in this. If this does not find a leak, we are back to Option 1. If it finds a leak, we go on to Option 3
3) replace coil at a cost of about 18x the cost of option 1

I am leaning towards Option 1.

In the quote for Option 3, the contractor lists an evaporator coil V60H210D176. I did a quick Google search and found that ADP makes a coil by this model number. But as far as I can tell this is a 5 ton unit that uses R-410A coolant. If I am only replacing the evaporator coil, can I change coolant or do I need to stay with something that uses HCFC-22.

Also, I would prefer to get a all aluminum unit that will last longer than replace with another one that has copper. Thoughts? Thanks!

[beshvac]

All of the questions you want answered are impossible.

1. How long should it take? Have no idea! Every installation is all custom and depends upon when and where the old unit is installed
2. Indoor and outdoor should match-there is no information on what kind of Frankenstein system you want to bring life to.

You already know there is a leak and what needs to be done. There are lots of people that take Option 1 every couple of months.................

[CoolinSD]

Hi,

I wanted to update those who posted in this thread. I ended up hiring an independent AC repair guy who came recommended from a trusted source. He did the following work:

1. Refilled the unit with Freon - it took about 2.5 pounds (out of 4.5 pound capacity so it was half full)
2. Unplugged the main drainage line - he showed me it was completely blocked by algea that accumulated over 20 years
3. Closed off an extra vent that was installed in a middle bedroom that was no longer used

This was about 10 days ago. The AC is working much better now. There is also air flow into our two front bedrooms again. Our master is not getting as much air anymore, but it is livable.

I am going to have him come back out in a month or so and check our Freon level. If the leak is relatively slow, we may just "top off" the system every summer for a few years and put off the expense of a new coil.

As luck would have it, our heat wave ended the day after the repair. If the front bedrooms get too hot when the temp rises, we may install an inline fan to boost air flow up front. It will be on a switch so it only turns on with the blower. I will have the ability to turn it off during the winter to prevent too much heat from going into those rooms.

Also thinking of adding a small gable fan to the attic to get some air flow up there. He confirmed there is plenty of vents for intake/outtake.

Thanks again for the advice! I know we will eventually need a new system, but if we can hold off a year or two I can look at using the funds to add solar power.