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I just bought this house. I was looking at the AC system.
Oustside is a Goodman CLJ-36-1 it is a 3-ton 12 seer unit. Inside is a U-36 coil which I think is a Goodman. Also a Carrire furnace. CLJ-36-1 was installed in October of 2001 in place of a burn out. Age of the coil I am not sure. Furnace is 1983 or 1986(house bulit in 1986). My question is what furnace and coil should I have to match the outside unit? I want to stay with Goodman. This system now is not cool the house to good on hot days. Thanks, jmb
06-20-2005, 09:58 AM
The CLJ36-1 is matched with the U36 coil with a SEER rating of 11.2 for that system. The furnace does not matter as long as the airflow is proper.
If the CLJ36-1 was added to the existing U36 coil you most likely have some issues though. There is a component on the inside of the CLJ called a filter/drier. When an existing coil is used, this filter/drier many times becomes partially blocked from moisture trapped in the oil that is in the existing coil.
You need to have a technician check your system thoroughly. What the techician should be looking for is that the system has the proper superheat per the charts provided with the outdoor unit. Then, the technician needs to check the subcooling of the system.
When the superheat is proper, if the subcooling is higher then 25º, it is most likely that the internal filter/drier is partially blocked.
Also, there should only be one liquid line (small refrigerant tube) filter/drier in the system. If there is another filter/drier on the outside of the unit it must also be removed.
What I prefer is to put a piece of refrigerant tubing in place of any internal filter/drier and install a new filter/drier outside of the condensing unit.
Basically, more information is needed.
I took a look at the system. Outside on the big line that sweats is a blue colored filter. Inside on the small hot line there is a gray filter. One of them need to be removed? Also the U-36 coil is right for the outside unit. I looked at the spec. for the coil and 1200rpm mim. for fan speed. I checked the furance and pulled the fan motor out and looked. RPM for it are 1075. Since the furance is close to 20 years old and fan RPM are not right. I would like to replace it. Which Goodman furnace should I get. Thanks, James
06-20-2005, 01:55 PM
RPM and CFM are two different things. RPM is how fast the motor turns. CFM is determined by the size of the blower wheel and how much air it is designed to move at a given static pressure.
As Robo has said, and he gave you very good information, call a competent tech and have him check your system operation. You may find that the large expenditure of a new furnace is not necessary. Even if you just want to go ahead and replace the furnace if you do not find the true reason for your unit not cooling properly you will just have a new furnace and still not be cooling properly.
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