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Topic: Roof mounted AC unit uses R22, which is no longer available. What to do? (Read 232 times) previous topic - next topic
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Roof mounted AC unit uses R22, which is no longer available. What to do?
It looks like the refrigerant in my roof mounted LD AC unit is R22, which is, of course, illegal to buy in the USA since 1/1/2020.  My unit is a Dometic Duo Therm, model 610015.305.
Has anyone with this model had your refrigerant topped off?  I'm assuming I will have to have the refrigerant unit switched/converted or buy a new AC unit. Has anyone had their AC unit converted over to a different refrigerant?
SoCal-Gal  (Tracy)
1991 26.5 RB
Previous 1988 22’ LD Multi plan
Previous 1992 Six-pack Camper
Spare the sealant, spoil the job.
Travelers: Tracy, spouse Anthony, Coton de Tulear, Gabby and parrotlet, Indigo
Re: Roof mounted AC unit uses R22, which is no longer available. What to do?
Reply #1 –
Quote from: SoCal-girl  - 
It looks like the refrigerant in my roof mounted LD AC unit is R22, which is, of course, illegal to buy in the USA since 1/1/2020.  My unit is a Dometic Duo Therm, model 610015.305.
Has anyone with this model had your refrigerant topped off?  I'm assuming I will have to have the refrigerant unit switched/converted or buy a new AC unit. Has anyone had their AC unit converted over to a different refrigerant?

What leads you to believe it needs recharging? Lack of cooling can have many causes.
If your A/C needs additional refrigerant, you have a leakage problem, the units are sealed with no easy way to recharge them, lacking the external valves needed for adding refrigerant and measuring the operating pressures. The only external seal is where the power wires enter the compressor,  a common point of leakage, everything else is soldered together.
The refrigerant lines need to be cut to allow evaculating and refilling, with a measured amount of refrigerant fluid and then recrimping and soldering the lines shut again. It takes very specialized equipment to do properly. The lack of valves eliminate the ability of a tech to measure the unit's internal operating pressure.

If it is old enough to need recharging, it’s old enough to consider replacement. I have not heard of anyone changing to different refrigerant, a common practice in older, R12 refrigerant cars but never in a roof-top A/C, the A/C was engineered to work most efficiently with a particular fluid. 
If you go ahead and recharge the unit, after finding and fixing the leak, R421A is the common replacement for home A/C units that came with R22.

Newer A/C units are ligher and more efficient than the older ones, most of the time when one needs internal work, its cheaper and better in the long run to replace the whole thing.

Larry


Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Roof mounted AC unit uses R22, which is no longer available. What to do?
Reply #2 –
There is no such thing as a little leak in these things, they only hold about a pound of gas and R -22 is a commodity. Make sure the coils are clean before you do anything else, both condenser and evaporator and that the filters aren't plugged. I really wouldn't retrofit a new refrigerant as many new refrigerants often need more condenser to work properly and the whole thing could turn into a bag of worms for you. If it was mine, I would fix it but I can't recommend it for everyone because not everyone will work on them. Cheaper to replace.

Jon
1994 MB
 
Re: Roof mounted AC unit uses R22, which is no longer available. What to do?
Reply #3 –
Thanks, JonS and Larry W, from your responses I now know more about my AC unit and I have a plan of action.

t.
SoCal-Gal  (Tracy)
1991 26.5 RB
Previous 1988 22’ LD Multi plan
Previous 1992 Six-pack Camper
Spare the sealant, spoil the job.
Travelers: Tracy, spouse Anthony, Coton de Tulear, Gabby and parrotlet, Indigo