Help - need new air conditioning condenser

[brickere]

We own a small condo that we bought a few years ago. The original in-wall air conditioning condenser/compressor died at the end of last year and now I need to replace it. Thankfully, the natural gas furnace and evaporator coil were both replaced before we took ownership of the unit, so that's good.

One of the local HVAC companies quoted me around $Xk to replace the condenser with a new on-ground unit. Since we're trying to buy a house this year and spending that much money to fix the a/c in a unit that we probably won't be able to sell anyway (in 6 months we've had three showings) just isn't possible for us. What I'd like to do is buy the materials and then find someone who knows what he's doing to do the labor - I think I've got both lined up now, but want to make sure on the parts/equipment end.

I'm currently looking at a couple of new condensers but I want someone with some real HVAC knowledge to weigh-in, please.

Currently, our coil is a Carrier CD5AXA024014ABAA (I found detailed info on it here, which is from here). It shows that it's a 2 ton model that can take either R-22 or R-410a refrigerant. On the coil's label it reads:

- CD5AXA024014ABAA
- 450 PSIG
- kPa 3102
- R-22 and R-410a with listed unit
- Listed 3R39 refrigerant evaporator

The two new a/c condensers I'm looking at are:

1. Goodman GSC130241, 2-ton 13 SEER, R-22
2. Goodman GSX130241, 2-ton 13SEER, R-410a

My questions are:

1. Am I understanding the model number of my evaporator correctly and that it is in fact a 2-ton unit?
2. Are the two condenser units listed above actually compatible?
3. Someone in the HVAC world told me that as long as the tonnage and the refrigerant types matched then they are in fact compatible true?
4. How hard (and what's involved) in converting our coil to accept R-410a since it currently uses R-22? Is it worth it? Should I just buy the R-22 condenser?
5. Aside from the line set/refrigeration tubing, what else will I need to buy?

Thanks so much for any help anyone can provide me!

[Special-K]

Pricing not allowed. Please review site rules.

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Mod Team

[brickere]

Pricing not allowed. Please review site rules.

Thanks,

Mod Team

Thanks for fixing it - I forgot I mentioned a price in this.

[BaldLoonie]

1. Am I understanding the model number of my evaporator correctly and that it is in fact a 2-ton unit?
2. Are the two condenser units listed above actually compatible?
3. Someone in the HVAC world told me that as long as the tonnage and the refrigerant types matched then they are in fact compatible true?
4. How hard (and what's involved) in converting our coil to accept R-410a since it currently uses R-22? Is it worth it? Should I just buy the R-22 condenser?
5. Aside from the line set/refrigeration tubing, what else will I need to buy?

1. Yes
2. No
3. No
4. Coil shouldn't be converted, you'll never get all the old oil out. If you really want to hack a new unit on the mismatched coil, stay R22. Or have it done right and install a matching coil.
5. Talk to the pro who will put this in. Usually GOOD dealers have enough work to do without putting in HO purchased stuff to mismatch. And if you buy this fine Goodman stuff on the net, you get no warranty.

[brickere]

1. Yes
2. No
3. No
4. Coil shouldn't be converted, you'll never get all the old oil out. If you really want to hack a new unit on the mismatched coil, stay R22. Or have it done right and install a matching coil.
5. Talk to the pro who will put this in. Usually GOOD dealers have enough work to do without putting in HO purchased stuff to mismatch. And if you buy this fine Goodman stuff on the net, you get no warranty.

Would you mind elaborating on why exactly the compressors above won't work? I'm not saying I don't believe you, but so far it's 2:1 (yes:no) that it will work, and I'd like to learn the specifics as to why you say no. Thanks!

[brickere]

still looking for input, please.

[BaldLoonie]

Outdoor units & indoor coils should be matched to get full capacity & efficiency. There are plenty of people that are happy slapping a new outdoor unit on a mismatched coil but that doesn't make it right.

I posted a study by Bristol Compressors showing that a 3 ton unit had to be overcharged by about 60% to get a 13 SEER machine to work on a coil meant for lower SEER. The 3 ton unit got about 2 ton at factory charge. Being way overcharged would get the capacity up to 2.5 ton and the measured efficiency was under 9 SEER. If that's what you want, go for it.

[brickere]

Outdoor units & indoor coils should be matched to get full capacity & efficiency. There are plenty of people that are happy slapping a new outdoor unit on a mismatched coil but that doesn't make it right.

I posted a study by Bristol Compressors showing that a 3 ton unit had to be overcharged by about 60% to get a 13 SEER machine to work on a coil meant for lower SEER. The 3 ton unit got about 2 ton at factory charge. Being way overcharged would get the capacity up to 2.5 ton and the measured efficiency was under 9 SEER. If that's what you want, go for it.

Thanks again for your reply. I understand your point, but I'm not so much concerned about "right" as I am about "wrong". In other words, if "right" is "ideal" (the "how it *should* be"), and "wrong" is "totally dysfunctional," then I want "ok", which is "functional, hopefully not [overly] destructive to much of the other HVAC pieces (namely the coil) but reliable even if it costs me more to run it on the days we do because it's not the most efficient."

I think maybe I asked the wrong question initially.

If it were you, how would you handle this scenario:

You own a property and can't sell it and it's depreciated by at least 20% of what you paid for it. It's getting too small for your growing family and small business. You can't sell it, but there is the possibility if you pull together enough cash you can buy a slightly larger property that will address your housing needs far better.

However, suddenly your a/c dies. Not replacing it really isn't an option, but in order to do it "properly" you basically delay the acquisition of the new property. So, what do you do in order to get a/c back so your wife and child don't cook to death and yet spend as little as possible?

Keep in mind:

- The systems has *always* been mis-matched
- The old system was massively inefficient and wouldn't cool your home to lower than 74 deg. on the hottest of days
- Repairing the old system is not an option

I suppose window units might be a viable option ... maybe.

Thanks again. I'm really not trying to be difficult.

[lowloss315]

If seeking approval to do the wrong thing regarding your indoor comfort is what you want, then I won't do that for you. You probably already know the answer on whether or not it CAN be done. Should you do it? No. You should be able to get these questions answered by the qualified HVAC technician you have lined up to do the work.