effect of exceeding maximum piping length in split type aircon

[radwin]

what is the effect when you exceed maximum piping length on split type air-conditioning units? is there a range in exceeding the range in the manufacturer's specification regarding piping length.

 

[MintJulep]

Pressure drop increases and capacity is reduced.

 

[Drazen]

Refrigerant piping is different from hydronic systems, if you exceed lenght too much, it can happen that expansion valves on evaporators (indoor units) will not work.

Exact allowance is deeply related to manufacturers, I had lot of such circumstances and found out that different manufacturers state different tolerances, someone's recommendations are on safe side, some are not. You would need to talk with manufacturers technical support if you want to come to the exact limits.

 

[TwinScrew]

^ Agreed. Ask your local sales rep. for a Long Line Design Guideline.

Also, be concerned with proper oil return to your compressor(s).

 

[Waramanga]

no warranty!!!!

 

[MechEngNCPE]

Trap the lines as per manufacturer recommendations. There are volumes of installation guidlines for this. Good luck.

 

[willard3]

Pressure drop increases, flashing increases, capacity decreases.
Velocity decreases limiting lubricant return ruining compressor.

 

[Wareagl487]

All are right on the money. Carrier offers the best data I have seen on the drop in capacities vs. length of refrigerant run. Worth taking a peak at - as I remember it being quite significant when you start exceeding 200 feet equivalent length.

 

[radwin]

you mean if the piping limit for example is 60 ft for a 2.5 hp wall mounted split type, the drop in capacity will be significant if you install it exceeding 200 ft?

 

[marcoh]

If you read the fine print, units are typically rated with 5m (say 15ft) of pipework. I would guess 60ft on a 2.5hp wall mounted split would have a effect on capacity, and 200ft would have a significant impact on capacity.