You lose approximately 1/2 PSIG per foot of vertical rise.
After you add your PD for length, bends, ells and FD. You should now look how much PD the LLSV has if you use one. May need to use a 1/2" LLSV.
You may find this hard to believe. But they sometimes forget to tell you everything in those instructions.
I'm not a Goodman dealer. So I don't install them enough to run into long line set situations with them.
I've done more then my share of long line sets, and have never used a LLSV when the evap is above the condenser, because of the line being long.
But, I must confess, I'm a chicken.
I call the factory when I'm doing a long line set.( I don't consider 75' long) Keeps warranty intact when they size it, and tell you what to add to the system.
I have only used LLSV when the line set was more than 80' with copper run underground and after there have been compressor failures. I have always used a 1/2" LLSV on 3/8" LL.
I have two Amana 2-stage units with 60' & 70" line sets and more than 20' rise. The units have CCH and hard shut off (non-bleed) TXV with a vapor loop. There have been no problems with these units and they are three years old. The Amana 2-stage has the same compressor as the the Goodman 5-ton 16 SEER unit.
If the installer installs a hard start kit make sure they use the proper two piece rated for the compressor not a cheap super boost type.
I have only used LLSV when the line set was more than 80' with copper run underground and after there have been compressor failures. I have always used a 1/2" LLSV on 3/8" LL.
Under ground line sets are a whole topic themselves.
Didn't mean to imply you don't use the correct size LLSVs. But many techs are not aware that they need to be sized.
Under ground line sets are a whole topic themselves.
Didn't mean to imply you don't use the correct size LLSVs. But many techs are not aware that they need to be sized.
Didn't think you were most don't realize that a 3/8" LLSV is not a full 3/8" ID and it is not apparent from the info on the box. I always respect you as articulate and professional, informative and not demeaning to anyone. You always appear to be informing with quality knowledge, it is a pleasure to contribute on threads that you frequent.
I have two Amana 2-stage units with 60' & 70" line sets and more than 20' rise. The units have CCH and hard shut off (non-bleed) TXV with a vapor loop. There have been no problems with these units and they are three years old. The Amana 2-stage has the same compressor as the the Goodman 5-ton 16 SEER unit.
This is really helpful, thanks. It's in line with what the installer is telling me.
Here is a follow up question - he said that if I want, he can put the condenser on the other side of the house, which would change the lineset length from 71' to about 55'. The advantage would be a 16' shorter lineset, and only about 10' in the attic (the 71' run would have 43' in the attic). The disadvantage would be significant drywall tearout/repair, condenser more visible from street, and having to re-permit the new configuration.
All in all, if the 16' shorter length does not buy me much in terms of efficiency, I'd prefer to go with the longer routing, but with easier installation and less visible condenser.
Are the benefits of the 16' shorter lineset worth the drawbacks that I mentioned?
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Originally Posted by beenthere
