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Makeit go Right
06-05-2007, 02:15 PM
If it is in reasonable condition, a customer will often want to take the aircon with them when moving premises, which is fair enough. The key thing, apart from being careful when transporting it, is to seal off the pipe ends to prevent ingress of moisture etc, AIUI.

Well, I saw a system the other day, after it was transported (by others) some months ago, and they had used electrical tape to seal off...one strip over each pipe end, and it had (no surprise) come away and was flapping in the wind. A bit more taping of the ends would have made the difference. My immediate instinct was - forget it... the thing is not worth the gamble.

Here's the question...If it had been pumped down and valved off when decommissioning it, before moving it, there should be no real issue with moisture getting into the condensing unit. With the Room Unit, one could just vac out in the normal way to ensure it was okay, and pipe up with new tube, as you would.

So, is that sloppy taping over the pipe-ends important, really? ie, is the machine no worse for wear after the tape failed?

Appreciate any comments/tips/ideas.

LRAC
06-05-2007, 02:20 PM
If that is the case and the service valves had been front seated i see no reason why it should be any different from when the units are delivered from new(except you've got the flare nuts missing).

If the unit is showing a positive pressure you should be ok, worth while reclaiming existing charge and start from fresh as you don't know if it contains excess charge from an extended pipe run installation.

Kind regards
Lrac

momo
06-05-2007, 04:33 PM
As LRac says Ref. charge check is one matter (if you saw it working before and where it was you could hopefully avoid emptying and filling, as you have the original working parameters/pipe length).

The open ends of the evaporator: check visually for dust - remember most economy A/Cs only have a capillary and NEITHER strainer NOR filter, so with any particles you risk stopping up the capillary, oils will catch dust and while you can warm and vac the unit for humidity, the dust will be drawn through the system.

Since there is a potential of damage resulting from the second hand state and the handling it has suffered: evidently any guarantee you can give is very limited.

The worst case of relocation I came across was: hacksaw cut pipes no sealing and no gas (R22) - NO COMMENT - a polite refusal followed. A year later I was phoned about the units not working. I know that "curiousity killed the cat" but I nonetheless went to have a look: evidently incompressible gases..., blocked capillaries, overheating compressors, pipes of in-adequate sizes etc etc. I gave a "reasonable" ;) estimate to attempt repair and heard no more till now... :D


A question now arises: Where should one put a filter in an A/C system (as in the case mentioned and keeping intervention to the minimum because of labour costs) when the metering device is in the outdoor unit and the liquid line has a mixed liquid/vapour mixture? And of what type?

The Viking
06-05-2007, 08:35 PM
Filters / driers in an A/C system, now here is a debate that will go on and on....

Personally so would I fit them after a compressor change.

Depending on if it's a heatpump or not you have a couple of options.

Liquid-line drier in TRUE liquid line, even if it means cutting the liquid-line and route it to the outside of the outdoor unit and back.


Suction-line drier, if cooling only it's easy but if it's on a heatpump then the suction-line would be cut between the reversing valve and the compressor then re-routed to the outside of the outdoor unit and back.


Relocating a unit?
Yes, it often happens for whatever reason the end user might have.
As long as the valves are shut on the outdoor unit, I would blast the indoor unit through with OFN then progress with installation as usual. However, the original charge would be discarded.

taz24
07-05-2007, 06:47 PM
If it is in reasonable condition, a customer will often want to take the aircon with them when moving premises,


Appreciate any comments/tips/ideas.




I have done a job just like that.
The unit was taken out without me seeing it running months earlier and the then stored indoors on some racking.
I was asked to install it in the new office.
I gave a price for a days labour with no garentee of leaving the job running. I made sure the customer understood that I would want paying no mater what.
As it happens it was a good unit and as far as I know it is still running almost 2 years later.

taz.

taz24
07-05-2007, 07:00 PM
Now I remember, my sds impact drill / chisel failed that day and what would of been a three or four hour job total time ended up taking a couple of hours longer because I had to knock the hole through by hand with a hammer and chisel.

Proper edwardian engineers bricks are very very hard.

Moral of the story is use the correct tools and the job goes a lot smoother.

taz

momo
07-05-2007, 07:08 PM
Now I remember, my sds impact drill / chisel failed that day and what would of been a three or four hour job total time ended up taking a couple of hours longer because I had to knock the hole through by hand with a hammer and chisel.

Proper edwardian engineers bricks are very very hard.

Moral of the story is use the correct tools and the job goes a lot smoother.

taz
Or checking/negociating installation placement: nothing like an iron bar reinforced lintel over a window or even better discovering that there was one there before :mad: , just where the drain & all go.:D

taz24
07-05-2007, 07:18 PM
Or checking/negociating installation placement: nothing like an iron bar reinforced lintel over a window or even better discovering that there was one there before :mad: , just where the drain & all go.:D

He He.
The cold room drain that when put through the wall to outside manages to be bang in the center of the one and only girder holding the roof up:) .

Cheers taz.