R22 Conversion to M099?

[Eddieclemons]

While I have many other concerns with my 88 52C that are more pressing, I do have a AC unit that needs service very soon. Since a 10lb bottle of R22 is $600 I am thinking about doing conversions as I start servicing my units. I am hearing about a little loss in efficiently but the M099 is a evacuate and go option. Anyone have any knowledge or real world experience with this conversion?

[oscarvan]

Check eBay I got 10lb for $239

[SKYCHENEY]

Isn't R410A also a direct replacement for R22?

[oscarvan]

Isn't R410A also a direct replacement for R22?

Yes. But you have to buy the new system with it. It requires a much higher pressure to do its job and cannot be retrofitted in older systems.

[rwaldrop13]

If your current unit is losing freon, have you been able to track down the leak? I'd check the service valves and connections - Tighten those before you add any freon, since otherwise you're pouring money into a hole. I pulled the cap off the service valves to check pressures in one of my failing units and it blew all the remaining freon right then. These were the original Crusair units, so they were 30 + years old. Amazing they still ran at all.

You've probably already figured that out - PO of my boat apparently was overcharging units to get thru survey and sale, within 3 months after we lost 2 compressors out of 4, and the leaking unit was already having issues at the air handler end. He rolled the dice and got lucky in this case.

If you hold an EPA freon certification (required to purchase freon), I'd check prices online but also local - Thermo King and Carrier truck and trailer refrigeration dealerships may have somewhat better pricing than more conventional sales locations.

We ended up installing stand-alone units for the galley/V-berth, and master stateroom and midships stateroom. More expensive upfront, but already saving me money on electric and stress.

[Eddieclemons]

Freon™ MO99™ (R-438A) Refrigerant, an R-22 Replacement

M099 is the go to direct evacuate/vacuum replacement for R22 in residential use. I was looking for cruisair experience with it.

[oscarvan]

If you are chasing a leak you can put a die in there.

https://www.amazon.com/ZeroR-Leak-De...1119484&sr=8-6

[rwaldrop13]

If you are chasing a leak you can put a die in there.

https://www.amazon.com/ZeroR-Leak-De...1119484&sr=8-6

Be careful with dyes. While I was a service manager with Thermo King, we had several units with compressor failures related to dye congealing in the system.

I didn't realize there was a direct replacement for R-22 - That being said, leak-checking is still critical to prevent further issues. Sorry.

[SKYCHENEY]

Yes. But you have to buy the new system with it. It requires a much higher pressure to do its job and cannot be retrofitted in older systems.

Really? Because several years ago I bought a new condenser unit from SPCoolin when he was still with us. It was identical to my original 1985 unit, but it had 410 in it. We pulled that out and charged it with R22.

Too bad Steve is gone. He was truly the expert on this stuff.

[oscarvan]

Really? Because several years ago I bought a new condenser unit from SPCoolin when he was still with us. It was identical to my original 1985 unit, but it had 410 in it. We pulled that out and charged it with R22.

Too bad Steve is gone. He was truly the expert on this stuff.

And I am no expert so I would like to believe you as it would buy me (a lot) of time on my units. I was just reporting what the various technical sites were telling me. But you sent me back in the rabbit hole and I found this:

https://legacyac.com/things-to-be-aw...-refrigerants/

But also this.... so it appears that MO99/R438-A is a viable option, with some caveats.

https://heatingcooling.fergusonhvac....ofit-solution/