Suction line sweat causing water leak

[The captain]

Got called out to a water leak the other day, Fujitsu high wall indoor unit 7 kw. Installed in a home living room. condensation was leaking from the suction line piping which was installed vertical into the ceiling space. After re sealing the insulation with duct tape and some more insulation the pipe sweat still leaks out and down the wall slowly. The room is about 13m x 7m with 2.4m ceiling. May be undersized unit???
Hot weather in australia about 40 'C last fue days.

[nike123]

What is humidity and temperature in area around pipe. What is insulation thickness?
What type of insulation is used?
Is it pre-insulated pipes with vapor barrier or some other insulation?

[monkey spanners]

I had something similar with a wall mount unit. After a few visits to site we found that the water was running down between the pipe and insulation from outside where birds had pecked away at the insulation and allowing rain to get in.

[digerious]

once moisure has penetrated insulation,the only way to get rid is switch off unit,remove old insulation,dy out suction.when fitting new insulation glue ends and silicone each end of run

[Magoo]

suggest that the suction line is a bit too cold for ambient conditions. Either system suction line is too long /creating abnormally low sst.
If system is designed for loading on compressor then system is short of gas, creating a falsely low suction condition, hence sweating.
Crank up the suction pressure.

[The captain]

Well we checked the evaporator coil TD and found 13'C which is good. Sst was at 10'C with R410a inverter system running 100%. Was thinking excessive sweating may be a sign of excessive heat load ie unit undersized for the room? Room maintains 24'C with ambient about 40'C. Keen to hear any ideas.

[nike123]

Well we checked the evaporator coil TD and found 13'C which is good. Sst was at 10'C with R410a inverter system running 100%. Was thinking excessive sweating may be a sign of excessive heat load ie unit undersized for the room? Room maintains 24'C with ambient about 40'C. Keen to hear any ideas.
Excessive sweating is sign of high humidity in surrounding air around pipes and/or insufficient termal isolation of pipes.

[alinga tonny]

what are the possible causes and solutions when the suction pipe ices up all through from the flare nuts to the evaporator fins in the indoor unit

[edcooper]

Low load, as in not enough air passing over the evap coil. Lots of possible causes such as no fan, dirty filter, blockage. Or low suction pressure. Is your suction pressure below freezing?

[nike123]

what are the possible causes and solutions when the suction pipe ices up all through from the flare nuts to the evaporator fins in the indoor unit
If indoor temperature is above 15°C you have one (or more than one) of following:


Faulty fan
Suction side blockage
Dirty filters
Low charge