Connecting and disconnecting refrigerant pipes

[pcatterall]

Still looking at split unit A/Cs ( as well as the water cooled jobbies) One advert suggests that the units can easily be connected and disconnected ( they say that there is some sort of one way valve).
If this was the case then this type of cooler would be viable for me ( I can leave the interior part fastened to the bulkhead and store the exterior bit while sailing and without shore power)

Is this ability to connect and reconnect without loosing gas really a possibility? I know that with DIY chest coolers you can clip fit once but not disconnect without recharging.
Thanks

 

[VicMallows]

For lack of anything better to read on holiday in places where air-con is necessary I have studied the installation manuals for these units in detail. I was surprised that following the correct procedure the bulk of the refrigerant can indeed be 'captured' in the outdoor unit, the valves turned off, and the unit disconnected. The problem comes when reconnecting as it is necessary to purge the indoor unit and pipework with nitrogen ......or is it with a vacuum pump? ...... to remove all trace of atmospheric moisture.

(I am sure one of the many refrigeration experts on here will expand/correct)

 

[superheat6k]

These fittings are designed for very occasional use only, and with sealed and evacuated pipe work. A small puff lost each time will have an effect after say 6-10 disconnects, and if any air gets in the system then other problems will arise.

You may be better trying to find a split unit with flexible interconnecting pipes. B&Q used to offer these, and some portables also use these.

I can assure you if there was a simple solution to this conundrum of simple refrigeration system preparation and charging, a vast industry would have taken it on.

 

[William_H]

I have fitted 2 split unit Aircons at home over some years. In both cases the outside compressor unit is sealed with correct amount of gas in it. You connect the inside unit with pipes then couple it up to the comprssor unit. One pipe has just a valve while the ohter has a fancy valve plus port. You have to couple a vacuum pump and completely evacuate the pipes and inside evaporator unit. Then you close the valve to the vacuum pump and open the valves in both pipes to allow the gas into the whole system.
I had a proffesional do the last one and he complained about the cost of refrigerant gas. (the kind that is acceptable for the ozone layer ie not a flourocarbon) he reckoned a refill for this very modest home A/c would be 150 squid just for gas.
So it would seem that a poertable split system where the units are separated would not be practical. As said the portable units with flexible hoses between the 2 and one unit that would fit through the front hatch would be your only option. good luck olewill

 

[pcatterall]

These fittings are designed for very occasional use only, and with sealed and evacuated pipe work. A small puff lost each time will have an effect after say 6-10 disconnects, and if any air gets in the system then other problems will arise.

You may be better trying to find a split unit with flexible interconnecting pipes. B&Q used to offer these, and some portables also use these.

I can assure you if there was a simple solution to this conundrum of simple refrigeration system preparation and charging, a vast industry would have taken it on.

Many thanks for that and the links you sent me ( and thanks for all contributions) . Yes, I am looking at the split units with connecting pipes, having said that, in most applications people probably don't want or need to be frequently connecting and disconnecting so maybee 'industry' is not pushing too hard to solve it?. William H's gas costs seem high to others I have seen quoted? I guess it should be less if just a 'top up' is required.

 

[maxi]

I have very recently done exactly that, disconnected the gas unions and subsequently re-connected, after replacing the control unit.

No problems whatsoever & the unit works perfectly. What is a possible problem is that: each manufacturer uses different unions & they are not interchangable should replacements be required.

 

[Avocet]

I'm intrigued by these systems. Surely you lose an evaporator full of refrigerant every time you disconnect it? On boats, do the condensers dump their heat into air (like a house or car) or water? Surely water would be more efficient?