Replacing R407 condenser with R22 cond.

[mahaff]

Ok, I know this is less than a great idea, but I am against a wall on this.

My current 18k BTU mini split sytem is an R407c unit and the condensing unit is finished. My problem lies in the fact that I have no easy access to the correct replacement, but I do have acess to an 18k BTU R22 condensing unit. Any thoughts on using this as a temporary solution.

Oh and the crux of the problem is that changing the evap unit to an R22 is also not possible at this time.

I have some serious issues preventing me from just getting the right one to do the job with, otherwise I would do that, but all I'm really planning on is trying to have this get through a few months until the correct unit can be shipped in. And I think it will work, but I just want to make sure I haven't forgotten something obvious ( a bad habit of mine)

Thanks for any insight or advice.

 

[tys90]

Just a thought, but it might not even be legal to do that. As of 2010 you can only use R-22 to service existing R-22 equipment, new equipment cannot use R-22. I don't know exactly where your situation falls under the requirements though. How about just replacing everything with a R-410a split system?

 

[imok2]

Mahaff
I found this from the School of Civil Engineering, Hunan University of Technology, Zhuzhou 412008, PR China

Sounds to me that what your proposing should work and the use of R-22 will be around for some years but the Mfg is over

The dynamic performance characteristics of the air source heat pump (ASHP) with refrigerants R22 and R407C during frosting and defrosting are studied. The results show that both refrigerant systems have similar performance characteristics, except that the performance of the R407C system deteriorated faster than that of the R22 system under frosting, and the performance of the R407C system attains its steady state faster than that of the R22 system after defrosting. R407C refrigerant can be used in either existing systems or in new systems that were originally designed for R22

 

[MintJulep]

I had a different take on the question than the previous two responders.

I am thinking that you have a system that was running R407c and the condenser unit died.

You have a similar condenser "designed" for R22.

You want to hook up the condenser and recharge with 407c.

I suspect that the R22 unit compressor is pre-charged with oil, and that oil is probably mineral oil.

It's well documented for conversions that you need to do a pretty good job of cleaning out the mineral oil before converting to R407c. This should be pretty easy with a condenser that hasn't ever been run. Dump out the mineral oil, pour in some POE swish it around a bit, dump and repeat a few time.

After that hook it up. It will make cold. It will probably make close to the same amount of cold the original R407c system did. You might notice a bit of a lack when the ambient temperature goes way up.

 

[TwinScrew]

tys90 -- FYI, we can still utilize new equipment designed for R-22, you can just no longer manufacture such units... kind of a grey area.

mahaff -- Does your mini-split utilize a TXV, or piston?

 

[mahaff]

Thanks for the replies. I see where I should have clarified a couple things.

MintJulep-You are corect except I want to actually charge the system with R22 and was wondering if the evap would play nice with it, so I wouldn't have to change the oil.

I am in the wilds of Eastern Europe and so I am currently confined to a solution on hand-No new systems easily obtained,etc....We can usually get stuff in a month or two and so I only need this to function temporarily.

I pretty much have to try it I just wanted a second opinion as it were, and I really appreciate the fast replies. Cheers.

 

[marcoh]

R407C was designed as a replacement for R22 so has similar proporties and might be ok to go backwards (typically thought R22 designed systems are changed over to R407C, not the other way around!)

 

[MintJulep]

It will probably work with R22 too. However, if you go that route you will have mineral oil throughout the entire system, making it harder to clean up and convert back to 407c in the future.

 

[tys90]

TwinScrew - You cannot install "new" equipment after 2010, regardless of manufacturing date. The definition of new is installing virgin R-22 where one did not previously exist. You can still service R-22 equipment or replace it with pre-charged components manufactured prior to 2010. Components that are not-precharged and used for replacing or servicing an existing R-22 system can use virgin R-22.

mahaff is replacing a non R-22 system with a R-22 system where one did not exist, which would seemingly not be allowed.