I've gotten conflicting advice on whether or not to replace the line between inside and outside unit. Some say the current line with R22 can be purged and then used with 410. Others say no, can't be thoroughly cleaned and will cause problems down the road. Unit is a heat pump, if that matters. Any thoughts?
I would replace the line if there were ANY doubt. Filter/dryer units can be installed for contaminants but I've never heard of one to filter R22 from an R410 system.
I agree, but there could be problems running the new line above a finished ceiling, that's why I'm seeing if there's any alternative.
Just posted in another group... my comment is at the end.
Above is true, but I always like to run a new lineset with a complete system.
Check with your local HVAC contractor. In allot of cases when you go with a change of using a different refrigerant, most newer units have stepped up the size of the suction line from lets say a 7/8" to 1 1/8" line for proper oil return.
Plus the newer units use a different refrigerant oil so you do not want any of the older oil to mix with the new oil. You can flush out the old oil but it does cost allot of money to do so,
Larger line for oil return??
Which crack jack box did you pull that one from??
Plus the newer units use a different refrigerant oil so you do not want any of the older oil to mix with the new oil. You can flush out the old oil but it does cost allot of money to do so,
The thought that comes to mind is why change?
tom @
We just went from the old to the new freon, and they didn't change our lines. They did a pressure test to make sure there were no leaks, and said the old lines were fine. We have not had any trouble at all.
James
For those who 'need to know.' The [rub] comes from the "different types of oil." The older refrigerant R-22 [Freon] uses mineral oil The newer refrigerant R-410a [Puron] uses a synthetic oil [PAG - poloyolyglycol]. The mineral oil from years of old is not compatible because of miscibility. The mineral oil tends to slug [thicken] under the newer refrigerant R-410a.
It is highly recommended that "if" you use the older copper lines with the newer gas, you should be aware that the manufacturer recommends less than 5% of mineral oil be allowed to mix with the newer gas. This concentration can be tested with a refractometer. It is better to run new copper, but if you have to use the older lines...... 5% is the highest concentration of mix allowed.
The larger suction line is needed with the newer refrigerant because of system capacity. If you choose to use a smaller refrigerant line, you system capacity will suffer.
I was very surprised when I saw what Coleman recommended for their:
Air Conditioning Condensing Units - 14 SEER Units 2 to 5 Ton, Single-Phase, R-22
Mfg. # Nom. Tons BtuH Cooling Max. Fuse Size Min. Circuit Amps Liquid Conn. Suction Fitting FRCS0241BF 2 24,000 20 12.1 3/8" 7/8" FRCS0301BF 2-1/2 30,000 20 14.9 3/8" 7/8" FRCS0361CD 3 36,000 25 18.1 3/8" 7/8" FRCS0421CE 3-1/2 42,000 30 17.8 3/8" 1-1/8" FRCS0481CE 4 48,000 35 20.6 3/8" 1-1/8" FRCS0601BG 5 60,000 50 31.8 3/8" 1-1/8"
fairly correct. Although on the 2-ton size 7/8" o.d. is a bit much. I think it likely goes with stocking less sizes in the warehouse. 7/8" is good to 3 or 4 Ton capacity depending on line length. [You can turn to Proper Piping Practices manuals for the refrigerant of choice.] You'll find that 5/8" is good for 2-Tons. 3/4" for 3-Tons. 7/8" 4-Tons, and 1-1/8" is good for 5 Tons for air conditioning applications using R-22 or R-410a.
If the suction return line is too large, you may have oil return problems depending if the evaporator coil is installed below the condensing unit.
This is why a professional HVAC/R contractor is needed. He can generally make the best choices for the particular installation. One that will provide years of trouble free operation.
I fully agree what you are saying but what feed back I am getting from the manufactures is really some what surprising me when it comes to warranty but then again I can understand what they are going through. They tell me that they have lost so many compressors because of contractors not using the right size copper and evaporator coils. They want the evaporator coil to be around two years old before you replace a condensing unit using the existing coil.
I have learned to go to
As you can see their 13 SEER condensing units are not that bad when using the existing copper and their 13 SEER chart goes somewhat you say below.
Air Conditioning Condensing Units - 13 SEER Units
1-1/2 to 5 Ton, Single-Phase, R-22Mfg. # Nom. Tons BtuH Cooling Max. Fuse Size Min. Circuit Amps Liquid Conn. Suction Fitting ERCS0181BB 1-1/2 18,000 15 10.1 3/8" 3/4" ERCS0241BB 2 24,000 20 11.8 3/8" 3/4" ERCS0301BB 2-1/2 30,000 25 16.7 3/8" 7/8" ERCS0361BB 3 36,000 30 18.9 3/8" 7/8" ERCS0421BB 3-1/2 42,000 35 21.9 3/8" 7/8" ERCS0481BB 4 48,000 35 20.6 3/8" 7/8" ERCS0601BB 5 60,000 50 31.8 3/8" 1-1/8"
.I've been reading this thread with some interest. Back in 1978 I installed a Carrier 3.5 ton unit, which, at that time, was the high efficiency model. It was 8.5. At that time it was called EER. Anyway, I was told in order to get that efficiency (in '78) it needed 1
1/8" suction line. Actually, at the evaporator and at the compressor/condenser, it is adapted down to a smaller diameter .... I think, 5/8" or 3/4". The condenser was also huge for a 3.5 ton unit ... it's about 42" high. It's interesting how things have changed. I guess if I ever have to change to the new refrigerant, it might be difficult. But, considering we are selling the house this year, it probably won't happen. Anyway, it's probably time for a replacement anyway. The new owners can worry about that.Moe J> I fully agree what you are saying but what feed back I am getting from
Why are you installing condensing units on coils that are not matching?
I have learned to go to
As you can see their 13 SEER condensing units are not that bad when using the existing copper and their 13 SEER chart goes somewhat you say below.
Air Conditioning Condensing Units - 13 SEER Units 1-1/2 to 5 Ton, Single-Phase, R-22
Mfg. # Nom. Tons BtuH Cooling Max. Fuse Size Min. Circuit Amps Liquid Conn. Suction Fitting ERCS0181BB 1-1/2 18,000 15 10.1 3/8" 3/4" ERCS0241BB 2 24,000 20 11.8 3/8" 3/4" ERCS0301BB 2-1/2 30,000 25 16.7 3/8" 7/8" ERCS0361BB 3 36,000 30 18.9 3/8" 7/8" ERCS0421BB 3-1/2 42,000 35 21.9 3/8" 7/8" ERCS0481BB 4 48,000 35 20.6 3/8" 7/8" ERCS0601BB 5 60,000 50 31.8 3/8" 1-1/8"
.What do you mean not matching?
In the past when most of the times I would find a condensing unit needing to be replaced and would replace like for like and inform the customer that I would know more after we get the new C/U back up and running. There has been a few times where we would find that he evaporator coil was in need of replacing.
Now not too long ago I had a customer who had condensing unit that was about 10 years but his existing furnace was about 3 years old. After the crew installed the new C/U, I asked them how it was running. They came back and told me the sub-cooling, superheat and all looked good. Now the system is still running and the customer has not complained.
But I just had happened to mentioned the job to the manufacture and they brought up the fact that since the coil was 3 years old that there may be no warranty. Why are you installing condensing units on coils that are not matching?
I have learned to go to
As you can see their 13 SEER condensing units are not that bad when using the existing copper and their 13 SEER chart goes somewhat you say below.
Air Conditioning Condensing Units - 13 SEER Units 1-1/2 to 5 Ton, Single-Phase, R-22
Mfg. # Nom. Tons BtuH Cooling Max. Fuse Size Min. Circuit Amps Liquid Conn. Suction Fitting ERCS0181BB 1-1/2 18,000 15 10.1 3/8" 3/4" ERCS0241BB 2 24,000 20 11.8 3/8" 3/4" ERCS0301BB 2-1/2 30,000 25 16.7 3/8" 7/8" ERCS0361BB 3 36,000 30 18.9 3/8" 7/8" ERCS0421BB 3-1/2 42,000 35 21.9 3/8" 7/8" ERCS0481BB 4 48,000 35 20.6 3/8" 7/8" ERCS0601BB 5 60,000 50 31.8 3/8" 1-1/8"
.You're an air conditioning contractor and you DON'T know what I'm talking about??????
What do you mean not matching?
In the past when most of the times I would find a condensing unit needing to be replaced and would replace like for like and inform the customer that I would know more after we get the new C/U back up and running. There has been a few times where we would find that he evaporator coil was in need of replacing.
Now not too long ago I had a customer who had condensing unit that was about 10 years but his existing furnace was about 3 years old. After the crew installed the new C/U, I asked them how it was running. They came back and told me the sub-cooling, superheat and all looked good. Now the system is still running and the customer has not complained.
But I just had happened to mentioned the job to the manufacture and they brought up the fact that since the coil was 3 years old that there may be no warranty. Why are you installing condensing units on coils that are not matching?
I have learned to go to
As you can see their 13 SEER condensing units are not that bad when using the existing copper and their 13 SEER chart goes somewhat you say below.
Air Conditioning Condensing Units - 13 SEER Units 1-1/2 to 5 Ton, Single-Phase, R-22
Mfg. # Nom. Tons BtuH Cooling Max. Fuse Size Min. Circuit Amps Liquid Conn. Suction Fitting ERCS0181BB 1-1/2 18,000 15 10.1 3/8" 3/4" ERCS0241BB 2 24,000 20 11.8 3/8" 3/4" ERCS0301BB 2-1/2 30,000 25 16.7 3/8" 7/8" ERCS0361BB 3 36,000 30 18.9 3/8" 7/8" ERCS0421BB 3-1/2 42,000 35 21.9 3/8" 7/8" ERCS0481BB 4 48,000 35 20.6 3/8" 7/8" ERCS0601BB 5 60,000 50 31.8 3/8" 1-1/8"
.
In cases where it's difficult to run new lines, can the old ones be flushed with solvent to remove the old oil?
Dave
Yes
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