LG mini split line length too long? options?

jake65892

I have 80' of line length with 6 'sharp' bends on a mini split install at my house. It's having an issue heating the room, won't heat it more than 20F vs outside ambient air temp. Haven't tried AC yet as it's not the season.

I bought and installed the outdoor unit (LG LUU127HV) and ceiling cassette unit (LG LCN127HV4) myself.
HVAC company ran the line set. HVAC company noted length on the mini split is 66' per the manual, but I put the outside unit 80' away with the 6 'sharp' bends. They are coming out Monday to look at it.

What are my options? Can they simply charge it more and it cost more to run? Or will I need to find a new mini split unit (yikes!)?

I have installation manuals if necessary for advice.

Thanks
Jake

SuperJ

Usually there is a length for which the factory refrigerant charge is adequate. If you go longer you need to add the correct amount for the extra length. There is a maximum length too.

Sometimes the unit works fine but is fooled by short cycling air. Try cranking the setpoint way up and see if it heats. If so then it's a sensing problem, you can solve this with a properly placed external remote room temp sensor .

SuperJ

I looked it up. You've exceeded the maximum length of 66 substantially. Perhaps there is something you can do to make the lineset path more direct?

jake65892

There may be, but not exactly aesthetically pleasing. Would essentially be by my front door.

I assume this isn’t something that is simply solved by adding additional refrigerant but less efficient?

jake65892

Maybe I can buy a bigger outdoor unit? LMU18CHV Says it’s good to 82’. Not sure if it works with my indoor unit though.

jake65892

Luu187hv outdoor unit is good to 164 ft. Anyone want a deal on a 12k outdoor unit?

SuperJ

jake65892 said:

There may be, but not exactly aesthetically pleasing. Would essentially be by my front door.



I assume this isn’t something that is simply solved by adding additional refrigerant but less efficient?

It would be worth checking that the correct amount of refrigerant was added to match the lineset. If they didn't add any then performance will likely be affected.

My Mits FH09 heat pump only comes with enough refrigerant for a 25' (each way) lineset. Anything further requires to carefully add refrigerant.

It may be necessary to pull out the charge and reweigh it back in to confirm the amount.
Don't get into just blindly adding charge.

pecmsg

Monday Morning, Call Tech Support with the Mod & Ser #'s of the indoor and outdoor units. Find what the Max line length is. If your too long nothing can be done, if not find out what the exact charge for that set up is. Pull the charge and weigh it. Compare to what was installed. If short FIND the leak. If not pull a vacuum and weigh in a new charge!

EBEBRATT-Ed

what @pecmsg said

GW

Did they add juice? This is a single zone ? There’s no way a single zone can carry 80’ without added refer