Carrier A/C, Again!

[Nandy]

Re: Carrier A/C, Again!

Wow, one side has about 2 large leaks but the other side has over 12 leaks. This seems too much to try to repair since the aluminum fins gets ruined every time I fix one. I got to 2 and saw the amount of damage I had to do. It it were 2 or 3 leaks no problem this seems too much. OR, am I missing something and those copper pipes can be pulled outside of the aluminum fins on the side???

 

[Nandy]

Re: Carrier A/C, Again!

I know this looks like a monologue but Im sure someone will chime in when they have time... so assuming that the only leaks were actually at the evaporator (which I believe to be true) can someone point me out if this is the right process:
1. Get a compatible evaporator, looking at ebay it seems that they are less than $300.00. (still need to figure out how to find a replacement unit, does it goes by models, size, type?) and braze it in place.
2. Add liquid drier canister (which my system dont have but the neighbors does???) in the high pressure line. About $30.00
3. Vacuum the system (how much or for how long?) with my 2.5 cfm pump, wait 30 min, check if I lost vacuum and if not then vacuum a bit more.
4. Charge the system to the 4.6 lbs noted in the label. About $175.00
5. Cross finger and enjoy 10 more years of trouble free cold air...

Estimated total $505.00

Any one care to fill in the blanks or add to it?

 

[Tim Frank]

Re: Carrier A/C, Again!

I know this looks like a monologue but Im sure someone will chime in when they have time... so assuming that the only leaks were actually at the evaporator (which I believe to be true) can someone point me out if this is the right process:
1. Get a compatible evaporator, looking at ebay it seems that they are less than $300.00. (still need to figure out how to find a replacement unit, does it goes by models, size, type?) and braze it in place.
2. Add liquid drier canister (which my system dont have but the neighbors does???) in the high pressure line. About $30.00
3. Vacuum the system (how much or for how long?) with my 2.5 cfm pump, wait 30 min, check if I lost vacuum and if not then vacuum a bit more.
4. Charge the system to the 4.6 lbs noted in the label. About $175.00
5. Cross finger and enjoy 10 more years of trouble free cold air...

Estimated total $505.00

Any one care to fill in the blanks or add to it?

This won't do all the blanks, but may contribute a bit.
My background is working on bigger equipment than home A/C, (and 20 years ago...) but the principals are the same...some of the components in home units are slightly modified, or one module subbing for several individual components, and/or the piping can be done a bit differently for economy of $$ and space.
All that to say some of my suggestions may not be practical in your situation.
1) Here is a link to get some info re: your evaporator. It will allow you to break down the model number into a set of specifications.
You could also call the company tech support line for homeowners and see what they can offer in further info.
http://www.adpnow.com/wp-content/uploads/2010/10/SG-HAC-28.pdf

2) If you are adding a liquid dryer, for convenience plumb it with a parallel bypass line so that you don't have to shut down to change canister. I have only worked on systems with a canister that contained disposable elements....a bit like many diesel oil filter setups. But I believe many small systems just have an in-line type dryer....if at all. If you do add this feature, in whatever way works for you, there are special "after rebuild" or "major intrusion" filters that you should run as the first and second filter change....and change after Day 1...Day 2 and Week 1.

3) You CANNOT over evacuate a system. The longer and lower the pumpdown the better. I did a 10 T/Day ice machine compressor rebuild, charged with Nitrogen, pumped down and held vacuum on it for 24 hours. Then recharged with nitrogen...pumped it down again for another 24 hours. That may be overkill, but ANY moisture in a small system is worse than in a larger one....and it is worth going that litle bit extra to try and get a clean system.
4) Not sure what refrigerant you are intending to run, but with a new evaporator, and maybe a new refrigerant, the line capacity may change, too, and your charge amount may also change , so chances are that your TXV may not be in range any more....and may need to be changed out. On larger equipment you can just replace the guts of the valve without having to change the casing...thus no silver soldering req'd.
Not sure what you have on your, system but you should check it out and verify its suitability with your modifications.

Not sure if that helps, but there you go....

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

I would doubt that any supplier is going to have that coil...There are companies that make coils...All you need is a 3 ton 10 seer cased coil with a TXV...Funny thing is I had two of those and just scrapped them last week from a job we just did...I can't speak for ebay, as a pro we don't use used parts...I just know that coil custom made is over $1000.00...

 

[Tim Frank]

Re: Carrier A/C, Again!

I would doubt that any supplier is going to have that coil...There are companies that make coils...All you need is a 3 ton 10 seer cased coil with a TXV...Funny thing is I had two of those and just scrapped them last week from a job we just did...I can't speak for ebay, as a pro we don't use used parts...I just know that coil custom made is over $1000.00...

Do these coils always come with the TXV as part of the coil package?

If I was assembling this, I'd want to discuss the piping layout, the compressor type and size, and refrigerant choice with someone who knew a lot about these systems. The TXV will cripple any layout if it is not the right one for the application,

In any event, this is a challenging project for any DIYer.
Hope this works out.Good luck Nandy.

 

[bigdee]

Re: Carrier A/C, Again!

I am still baffled why this coil has so many leaks.......very unusual. There are only two things that come to mind,and that is chinese drywall (THE NUMBER ONE CAUSE OF LEAKING EVAPORATORS)or you previously had a compressor replaced due to the original one having burned up the windings which will create a very evil acid in the system if not properly cleaned up.

 

[Nandy]

Re: Carrier A/C, Again!

There are the type of coils I find on ebay:

http://cgi.ebay.com/3-ton-evaporato...676?pt=LH_DefaultDomain_0&hash=item27b1fde3b4

This should be very close to the one I have just by judging the little info they have on it. Can anyone guess why the difference on price? the item is new and similar to mine, it is uncased but the cased ones are not $100 more....

Here are the dimensions of the evap coil and the case:

It might not be apparent but the 19x13 measurement is of the top opening (flange opening) and the bottom opening is 13.5 x 20 (not shown).
So all I need to find is a cased unit that the dimension of the case fit in the duct case and furnace case (even if the coil itself does not have the exact same physical size), be 3 ton and have a seer of 10. What about if the seer is higher? will that cause a problem? Getting paid friday or monday so I will pull the trigger then. Should I flush the system too since it never had a filter and God knows if anything in it killed that coil?

Thanks for the help guys!

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

Being a strait cool with a gas heat, The 13 seer "might" not be a problem...Your condenser may not have enough volume to keep up with the larger indoor coil though...I would call a carrier distributor like sigler and reeves and ask if the ARI guide shows that coil and your condenser as a match...

BTW after the right coil is selected this job is a piece of cake...Insert slot A into tab B, seal, braze, evacuate, charge...If you get a case coil just mount it to the furnace and plate off the excess that hangs over the furnace with sheet metal and seal it with foil back tape...

As for the txv question...A TXV will compensate for load better then a flo-rator piston type metering device that carrier uses...In a fixed orifice type system superheat and the coils ability to absorb heat increases as the outdoor temperature goes up and the pumping pressures get higher...A txv uses the bulb on the outlet of the evaporator to allow enough liquid through to provide a set amount of suction superheat...Basically when doing a job like this a txv will compensate for a certain amount of size difference...So the a 3 ton txv that flows in one direction and is checked in the other will work fine in this system...Actually I added txv's to my GF's fixed orifice systems last year and all told she saved 100$ a month on her bill in the summer time...

 

[Nandy]

Re: Carrier A/C, Again!

So when I ask for compatibility it is not like a range that they will say, for example: anything between 2.5 to 3.5 ton evap with a seer. Between 9 and 12, no larger than C x X inch or smaller than G x F? Do I have to call for each prospective evap?

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

The ARI guide will say if that exact model coil can be used with that exact model condenser...My guess is no, but the fact that ICP is or was part of Carrier and they are both 3 ton I suppose its possible...ARI certifies that the systems match and there is a real world efficiency number associated with the system...

I will call Jim at Sigler here in phoenix and ask what he thinks of your situation and that coil...He is the local tech support for residential units and I know him pretty well...

 

[Nandy]

Re: Carrier A/C, Again!

Well, that coil was an example of what I found but I was not yet considering it. I started looking last night and will make a compilation of what I think might work. Right now I have looked at this one as a possible match:
http://cgi.ebay.com/Carrier-3-Ton-C...806?pt=LH_DefaultDomain_0&hash=item3cb855aec6
Thanks for your help.

PS - Carrier gave me a cnphp3617ata as a replacement for the ADP. They were trying to make sure the above model from ebay and this other model from ebay is compatible but I got disconnected. The only issue I see from the one above is that my unit is build horizontaly (my furnance is to the right side of it and the plenum box is to the left) and that first ebay unit dont seem to have a tray for that installation.

http://cgi.ebay.com/EVAPORATOR-COIL...783?pt=LH_DefaultDomain_0&hash=item45f81cb2d7

I called the seller for the above unit and after getting a bit info he told me that it is compatible, Im just not sure if he just said that to sell it. He was in the road but maybe he knows more than what I think he does...

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

I talked with carrier today and they tell me that a 13 seer coil with a txv on your system will work as long as the tonnage is correct...You have a 3 ton and you need a 3 ton coil with TXV...If it were a heat pump you would be screwed...They told me that there is no way to know what the seer rating will be afterwards, but it won't be worse then the 10 seer you already have...

I would get a coil that designed to be horizontal and install it...you can always flip the coil where the lines are on the back and also if the A part is facing into the airflow it will still work...You lose a marginal amount of capacity but it isn't even measurable...The bottom line is anything that's 3 ton with a drain pan for a horizontal coil can be made to work...

 

[Nandy]

Re: Carrier A/C, Again!

Those are great news! I will order tomorrow. Thanks, will let you guys know how it goes.

 

[Nandy]

Re: Carrier A/C, Again!

I ordered this evaporator coil:
http://cgi.ebay.com/ws/eBayISAPI.dl...akeTrack=true&ssPageName=VIP:watchlink:top:en

I ordered this liquid line filter:
http://cgi.ebay.com/Valcon-TD-163-A...634?pt=LH_DefaultDomain_0&hash=item19c3b087da

I supposed that filter only has to be changed if there is a compressor failure or if it blocks. Could it be a good idea to put a port after the filter to see the real pressure going to the coil?

I only have one 15% silver rod left, hope it is enough for these connections, evap lines and filter.

I will keep you guys posted.

 

[Tim Frank]

Re: Carrier A/C, Again!

I ordered this evaporator coil:
http://cgi.ebay.com/ws/eBayISAPI.dl...akeTrack=true&ssPageName=VIP:watchlink:top:en

I ordered this liquid line filter:
http://cgi.ebay.com/Valcon-TD-163-A...634?pt=LH_DefaultDomain_0&hash=item19c3b087da

I supposed that filter only has to be changed if there is a compressor failure or if it blocks. Could it be a good idea to put a port after the filter to see the real pressure going to the coil?

I only have one 15% silver rod left, hope it is enough for these connections, evap lines and filter.

I will keep you guys posted.

1) Filter? You need a dryer....or a filter-dryer. If it is just a filter, I don't think it is what you need. From your description of your work to date, your biggest challenge is going to be getting the system really evacuated so that it is dry.
2) If by "port" you mean a liquid sight glass, that would be a good addition....but get one with a system moisture indicator. That will give you an idea of how dry you managed to get the system. Keep changing those dryers until you get the green dot.

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

You have what you need...That "Filter" is a liquid drier...just make sure the arrow points to the evaporator...As far as ports go, I wouldn't worry about it...3 degrees temperature drop from in to out is what we look for to say they need to be replaced...As afar as one rod left goes, I know for sure I can do that whole job with one rod...So it can be done...Should have 2 couplings and either end of the drier...You don't need any access ports or anything at the coil...You have them at the condensing unit...As far as putting in valves to change the drier without evacuating that's a complete waste of 100$ in this size system...If you use a micron gauge and pull a good vacuum < 500 microns Air/moisture isn't an issue and worse case you can close the liquid port, pump the charge into the condenser and then change your drier and evacuate and recharge...valves and extra fitting leak, its just not worth it...

Sounds like you are on the right track...

For what its worth for < 10$ you can get a single use moisture/acid tester...Parts house have several different brands and most of them work...Sight glasses are worthless imho...

 

[Nandy]

Re: Carrier A/C, Again!

So the latest update is:evap will be here tomorrow but the dryer won't be here until the 13th... It seems I will have to spend 5 more days sleeping in a muggy room ( it bothers the family more then me) waiting on that filter unless someone can tell me how to "park" my charge on the condenser. I found a reference to that (which is what I think hacardworkingguy is saying also) but I haven't read how to do it.

So I can put this together minus the filter, do the vacuum, load the freon then when I get the filter I can close the liquid line valve, watch the suction line until psi is at or close to 0 then cut the compressor off, close the suction valve, brace the filter, vacuum again, then release the freon parked at the condenser by opening the valve, then open the suction valve and get the ac back on, check psi's to be right then I'm done? Are these the correct valves to close (on top of the liquid/suction line valve).

So when the valves are closed the liquid/suction line ports arein the "other" side of the compressor and condenser?

Thanks!

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

Close the liquid line, push the contactor, the suction will come down to zero, then the high side will eventually go to zero, then stop the unit and close the suction line...The charge will be in the condenser....You can then add your drier in the liquid line with the arrow pointing towards the indoor coil, pull a vacuum and release the charge(high side first)...

If you use a micron gauge and pull a decent vacuum the system can run a week without a drier and it won't be a big deal...

 

[Nandy]

Re: Carrier A/C, Again!

Got the coil yesterday, realized my width is their height and you can picture it. There might be a case to make this work the way I imagine it but I was not worried about that. Anyway, I got the case to the attic, attached it to the furnace and the plenum. Today I brazed the lines using a wet rag as a heat sink. Did vacuum for 4 hours, test for leaks but it held vacuum fine, then put 4.6 lbs of refrigerant and the system starts cooling. However, following the chart my suction line pressure should be around 157 psi (85 deg outside) but it only made it to 85 psi. I could not measure the liquid line pressure because my gauge manifold is for r134 and so are the hoses and cannot handle connecting the line quite right without loosing freon. I lost quite a bit of refrigerant in the attempt however connecting/disconnecting to the suction line is not much problem. I loaded a bit of refrigerant back to get it to the psi it was before I lost that refrigerant.
The air incoming to the coil is 81 deg and the air going out is 59 so I think it is quite working. However, can anyone dear explain why after loading the amount of refrigerant that is on the label I am still half the pressure I should be? I know this coil is larger but I would not think that is causing the problem. C'mon guys, give me y'all best bet. Should I load more refrigerant? Im hesitant to do that...

 

[bigdee]

Re: Carrier A/C, Again!

For a r-22 system your not too far off. Let the system bring the indoor temp down to 75 and check again to see if it falls to around 65 psi. A 22 degree drop across the coil is pretty good but fan speed also factors into the equation so your looking at ballpark. Put a amp-clamp on the compressor and check it against the nameplate FLA.