Any HVAC experts want to weigh in on something...

[AustinChief]

My parents in DFW have an old system that it appears the evap/coils on the air handler are shot. It's an R22 system and they are trying to see if it is worth upgrading to r410 now. My question is... could they replace the evap/coils on the air handler and then also just replace the condenser on the heat pump and get away with a cheapish conversion to r410 or will they need to run new lines and replace the whole air handler and heat pump.

The other option is to just replace the evap/coils and stay R22 but that seems like a pretty big expense to not just go ahead and upgrade things.

[plbrdude]

Originally Posted by AustinChief

Split system. Air handler inside with evap/coils and then I'd guess about 25 ft of line (3/8 and 7/8 does that sound right?) running outside to heat pump.

Inside coils have the leak.

if its a really old system your evap coil might be on the supply air side, if it's fairly new even within 20 yr the evap coil should be in the return air side. that being said you could replace the evap coil in the air handler. not knowing brand i would guess that the coil could run anywhere between 275 to 425. plus near to 5-8lb of r-22 depending on tonnage if its all leaked out. maybe 4 to 6 hr in lbr. 22 could be $20+ per lb now, lbr rates for that area may be well higher than $60 per hr. you could be pushing $1000 for just that.

the condensor you speak of changing is the outside unit, you don't convert a condensing unit from 22 to 410a. a/c or heat pump you change the unit, which also means you change the a-coil, which in this case prolly means the air handler. the line set can be left and flushed if its been brazed, if its been stay bright soldered best to change it too as 410 pressures are well higher than 22. on a hot day your liquid side could push toward 500psi; wouldn't trust stay bright.

unfortunately you're prolly lookin at a sysyem change out.the only other option if you want a newer outside unit is to see about a dry 22 unit, then go a coil and ht pmp if it's available.

that's my 2 cents worth anyways.

[Bugeater]

Originally Posted by AustinChief

Yep, I was referring to the backup electric heater I just assumed it's all part of the same air handler, I was probably wrong on that. I made that assumption because the damn air handler is MASSIVE, it's like the size of a refrigerator on its side.

It's something like this (but not exactly) http://www.goodmanmfg.com/Residentia...8/Default.aspx

My concern is the vast amount of labor required to replace the entire unit(I don't even see how it was put in in the first place) as compared to the POSSIBILITY of replacing just some of the guts (evap/coils). Of course, it may just be cheaper to buy the whole unit, I have no clue.

Oh hell, I've never even seen anything like that before, I can't even begin to tell you wtf you're up against.

This is what you see in homes up here:

[AustinChief]

Originally Posted by plbrdude

if its a really old system your evap coil might be on the supply air side, if it's fairly new even within 20 yr the evap coil should be in the return air side. that being said you could replace the evap coil in the air handler. not knowing brand i would guess that the coil could run anywhere between 275 to 425. plus near to 5-8lb of r-22 depending on tonnage if its all leaked out. maybe 4 to 6 hr in lbr. 22 could be $20+ per lb now, lbr rates for that area may be well higher than $60 per hr. you could be pushing $1000 for just that.

the condensor you speak of changing is the outside unit, you don't convert a condensing unit from 22 to 410a. a/c or heat pump you change the unit, which also means you change the a-coil, which in this case prolly means the air handler. the line set can be left and flushed if its been brazed, if its been stay bright soldered best to change it too as 410 pressures are well higher than 22. on a hot day your liquid side could push toward 500psi; wouldn't trust stay bright.

unfortunately you're prolly lookin at a sysyem change out.the only other option if you want a newer outside unit is to see about a dry 22 unit, then go a coil and ht pmp if it's available.

that's my 2 cents worth anyways.

Thanks!

Yeah I knew you couldn't "convert" the outside condenser in the heat pump I was just thinking that since they have to replace the a-coil in the air handler (I'm assuming the a-coil and evap are same or am I way off here) that they could go with an a-coil that handles r410 (pretty sure the new Goodman's have same fittings) and go ahead and replace the heat pump's condenser as well. Or would you have to replace the entire heat pump?

I have no clue on the soldering, which obviously could be an issue.

Just so you know, the air handler is a Goodman A49-15, I think it may be from around 2000. Not sure on the make/model of heat pump but I know it was manufactured in July 2004.

[AustinChief]

Originally Posted by Bugeater

Oh hell, I've never even seen anything like that before, I can't even begin to tell you wtf you're up against.

This is what you see in homes up here:

Yeah, this is Texas, that little thing couldn't handle a closet down here! Actually I think we are looking at same basic thing just bigger and on it's side and in the crawlspace above the laundry room. I really am boggled by the location of it. There is simply no way in hell the thing could have fit through the access panel... well, now that I think about it, I guess if you removed the entire door/stairs thingy maybe it could squeeze in. I'll have them get some measurements now that I have the model number and specs for the air handler.

[Bugeater]

Yes, the A-coil is your evaporator (but it acts as a condenser when the heat pump is in heating mode)

The heat pump IS the outside condensing unit. It's just like an standard AC condensing unit, but it has a reversing valve and some other extra bullshit on it.

[plbrdude]

Originally Posted by AustinChief

Thanks!

Yeah I knew you couldn't "convert" the outside condenser in the heat pump I was just thinking that since they have to replace the a-coil in the air handler (I'm assuming the a-coil and evap are same or am I way off here) that they could go with an a-coil that handles r410 (pretty sure the new Goodman's have same fittings) and go ahead and replace the heat pump's condenser as well. Or would you have to replace the entire heat pump?

I have no clue on the soldering, which obviously could be an issue.

Just so you know, the air handler is a Goodman A49-15, I think it may be from around 2000. Not sure on the make/model of heat pump but I know it was manufactured in July 2004.

you very well may can get an a-coil, which is the evaporator. one to fit that should still be available, if the heat pump is only 9 yr old i'd be fairly temped to keep it.
the heat pump is the outside unit, so when you say the entire heat pump it would be the outside unit.

not sure if a 410a coil would fit in that air handler as they are usually a little bigger than a 22 coil. taller usually, which can be a headache.

if you were to upgrade to 410 it would prolly be wise to match system and change inside and out, just have line set checked close. it possibly could be left if it would be a total pain to change.

[AustinChief]

Originally Posted by plbrdude

you very well may can get an a-coil, which is the evaporator. one to fit that should still be available, if the heat pump is only 9 yr old i'd be fairly temped to keep it.
the heat pump is the outside unit, so when you say the entire heat pump it would be the outside unit.

not sure if a 410a coil would fit in that air handler as they are usually a little bigger than a 22 coil. taller usually, which can be a headache.

if you were to upgrade to 410 it would prolly be wise to match system and change inside and out, just have line set checked close. it possibly could be left if it would be a total pain to change.

Originally Posted by Bugeater

Yes, the A-coil is your evaporator (but it acts as a condenser when the heat pump is in heating mode)

The heat pump IS the outside condensing unit. It's just like an standard AC condensing unit, but it has a reversing valve and some other extra bullshit on it.

Yep I know the Heat Pump IS the outside condenser unit. I was just referring to JUST the condenser part of the heat pump outside and not the whole shell and fan stuff. I am not doing a great job of communicating all of this!

Let me start over. I was thinking they could either A)replace a-coil as is and stay with R22 which is going to cost them a bunch to recharge. (something like $600 quoted to them just for recharge, I think) or B)replace a-coil with one for R410 and then of course they would have to replace the condenser in the heat pump outside to match. It sounds like you guys are saying that you don;t replace the condenser alone but the entire unit. Or of course C)replace the heat pump outside and the air handler inside which is going to be a massive job that I think will end up well over $6k or even $7k

I want to recommend option B if it is at all feasible, since in my mind I was thinking they could get away with a job costing closer to $3k and have basically the same result as option C but without the brand new warranties.

OK, let me know if my thinking is crazy talk.

OH and I'm almost 100% certain Goodman makes an R410 a-coil that would fit this old air handler.

[nstygma]

i think the term you were looking for is compressor.
how do you know the leak is in the a-coil and not some other place?

so you've got a 4ton unit with 3/8 & 7/8 lines. wholesale price from Johnstone Supply for an uncased coil for that is basically $415 and a new 410a copeland scroll compressor is $820. so much hassle to replace them though, then what if it doesn't work properly?

better to have peace of mind for the next decade+ with a new system & warranty.

[Chief Roundup]

Originally Posted by AustinChief

I know the coils need to be replaced, they are the problem. It's just a question of replacing them and staying R22 or replacing the evap/coils AND replacing the heat pump's condenser to go R410 ... if that is even possible... or replacing the whole system inside and out.

One of the biggest issues is the placement of the air handler.. I honestly have no clue how they got it installed in the first place. It is huge and the the access is not.

You cannot mix a 410a system with a r-22 system in any manner. Those refrigerants have different boil points so they will change from a liquid to a gas state at different pressures. They also use different expansion valves. The refrigerants operate at completely different pressures. The 410a is a lot higher pressure. If you put a 410a compressor on a r-22 indoor coil the compressor would blow out the u bends in the indoor A coil.
Yes they should upgrade because it will be cost prohibitive in the future if they do not. The drop in replacement for R-22 is more expensive than 410a. 410a refrigerant will only get cheaper. That replacement for the R-22 will continue to get more expensive because there is and will continue to be less and less in use.

[Chief Roundup]

Originally Posted by AustinChief

Yeah I can see this point... but I'm just thinking that the R22/R410 closed "system" is basically [evap/coils - lines - condenser]. I just can't see how the blower motor or electric heater element or any other parts of the air handler or heat pump would make a difference. Which is why my thought is that replacing the condenser and evap/coils would be all that was needed unless there is some crazy difference in the line sizes.

I finally remembered I have a buddy who does this for a living in Austin who I have sent a message to. Hopefully he can set me straight. I have a sneaking feeling the costs will be about the same no matter on this.

Interesting guy who has been doing this for years after retiring from profession bull riding. He even came back for a while and tried the "senior" circuit.

A lot of the differences are also in cabinet size. To get the higher efficiency ratings that the gov is forcing on everyone they have had to make the coils bigger. Those coils will not fit into the older cabinets. The blower motors can be different or the same. That depends on whether they are going back with the same size of equipment. They going back with a 3 ton unit if they had a 3 ton unit previously. But there again. Why not replace the blower and strips and get some warranty. To replace a blower motor will cost around $500.

[Chief Roundup]

Originally Posted by Bugeater

Ok, then it must be a heat pump with an electric backup furnace? You had me confused when you started talking about heating coils and blower motor. That's all part of the furnace and the heat pump system should be able to be replaced without touching that. The evap should be mounted in a plenum right above the furnace, it's not part of it.

Dude not true at all. The evaporator coil will ALWAYS be on the return side of the blower INSIDE the air handler cabinet when dealing with a heat pump.
A gas furnace will have the evap coil on the supply side of the heat exchanger but prior to the plenum box.

[Chief Roundup]

Originally Posted by Bugeater

Oh hell, I've never even seen anything like that before, I can't even begin to tell you wtf you're up against.

This is what you see in homes up here:

exactly what I was talking about. coil right on top of the gas furnace.

[Chief Roundup]

Originally Posted by AustinChief

Thanks!

Yeah I knew you couldn't "convert" the outside condenser in the heat pump I was just thinking that since they have to replace the a-coil in the air handler (I'm assuming the a-coil and evap are same or am I way off here) that they could go with an a-coil that handles r410 (pretty sure the new Goodman's have same fittings) and go ahead and replace the heat pump's condenser as well. Or would you have to replace the entire heat pump?

I have no clue on the soldering, which obviously could be an issue.

Just so you know, the air handler is a Goodman A49-15, I think it may be from around 2000. Not sure on the make/model of heat pump but I know it was manufactured in July 2004.

As I have already informed you. You cannot put an R-22 coil or condenser with a 410a coil or condenser. Yes the evaporator coil is the same as an A , N or slab coil in the indoor unit.

If it is a Goodman unit replace the whole thing. Goodman products are the absolute bottom of the barrel.

[Chief Roundup]

Originally Posted by AustinChief

Yep I know the Heat Pump IS the outside condenser unit. I was just referring to JUST the condenser part of the heat pump outside and not the whole shell and fan stuff. I am not doing a great job of communicating all of this!

Let me start over. I was thinking they could either A)replace a-coil as is and stay with R22 which is going to cost them a bunch to recharge. (something like $600 quoted to them just for recharge, I think) or B)replace a-coil with one for R410 and then of course they would have to replace the condenser in the heat pump outside to match. It sounds like you guys are saying that you don;t replace the condenser alone but the entire unit. Or of course C)replace the heat pump outside and the air handler inside which is going to be a massive job that I think will end up well over $6k or even $7k

I want to recommend option B if it is at all feasible, since in my mind I was thinking they could get away with a job costing closer to $3k and have basically the same result as option C but without the brand new warranties.

OK, let me know if my thinking is crazy talk.

OH and I'm almost 100% certain Goodman makes an R410 a-coil that would fit this old air handler.

Just to verify for you. You CANNOT use a 410a coil with a R-22 condenser/compressor. The bulb that the TXV, expansion valve, uses to control how much refrigerant the valve lets by is charged with 410a refrigerant. That bulb will either allow too much refrigerant by or not enough. The bulb is strapped to the copper lines in the coil. It is suppose to sense the temperature of the refrigerant flowing through the coil and open the valve the proper amount. Those temperatues need to be the same for the valve to operate correctly. Those temperatures will not be the same if you put 2 different refrigerants together. This will prohibit the unit from working correctly and cost them even more money.

[Chief Roundup]

Welding is the same. And you don't have to replace the copper lines as long as they are proper sized. They make a flush to prepare the old existing copper lines for the new refrigerant. It is however highly recommended that you replace them to protect your investment.