Split System max pipe run length?

[fridge doctor]

Hi,
Anyone know off the top of their head what might be the recommended pipe run length for a 12,000Btu Split. The unit is under performing, 2 years old, little use, it's in a first floor bedroom, Outdoor unit at ground level, and pipe run of approx 15metres. My view is that it is about double the recommended maximum. What do you think ?

[monkey spanners]

Need to know the make and model really but as a guess 10m max separation and 5m lift/drop.

[Eeram]

On average, a 12000 Btu unit has a maximum pipe run of about 7 meter on most makes.

Remember that nowadays the capillary tube sits in the outdoor unit. That means that your long pipe run with the small diameter pipe is now part of the evaporator, which actually means that you are sitting now with a oversize evaporator!

How are the 2 pipes insulated? Seperately or both in one insulation or no insulation?

[fridge doctor]

Pipes are insulated seperately. 2.5M outside, then buried into the concrete wall, vertical 4M, Then across bedroom floor 6M and up inside wall again another 2.5M to indoor connection. Therefore total vertical 6.5M ... As you say even on quarter tube, this is a lot of extra evaporator and a lot of strain on the system... Thanks.

[paul_h]

Hi,
Anyone know off the top of their head what might be the recommended pipe run length for a 12,000Btu Split. The unit is under performing, 2 years old, little use, it's in a first floor bedroom, Outdoor unit at ground level, and pipe run of approx 15metres. My view is that it is about double the recommended maximum. What do you think ?

It varys between make and model, but normally they are precharged for 7m. Some have a max of 10m, some have a max of 15m. At the bare minimum it would need extra refrigerant. But getting the make and model and finding someone with the installation data would be the best bet.