R404a to R407a Retrofit

[Jurg]

Hi All,

Due to the ever increasing price and the fact 404a is being phased out I've been tasked with coming up with a plan to change it to 407a. The system in question contains around 600kg and is a multipack system, which operates at around 8 degrees Celsius currently and will do for the foreseeable future.

In regards to the things being considered I've listed below things that may need changing in order to accommodate this change:
- TEV's
- Pressure Switches
- PRV's
- Drier Filters
- Schraeder Valves
- Compressor oil change

If I've missed anything please feel free to tell me, any advice would be much appreciated.

Jurgen

[FaultCode]

Is R407a the best choice ?

Some alternatives maybe... http://bit.ly/2eswIeT

[Icemankool]

Hi Jurgen
You've probably done this now, but I would have used R442a...
Unlike most of the other replacements, this is more efficient than R404a
https://www.boconline.co.uk/internet.lg.lg.gbr/en/images/R442A-RS50-Brochure410_129184.pdf?v=1.0

[hookster]

I have been using R448A and R449A for retrofitting from R404a and this has been the far simplest change out process with these two refrigerants.

Always change the oil!

[3polxin]

If I may know, the difference between refrigerant 404a and a [advert removed] is better suited for air conditioning engines.

[ICE/RUNNER]

We are using R448a when changing from R404a new filters and adjust the suction target. We have one site using R449a it's a pain as this gas is not readily available in large quantities we usually need 100kg per brake down and takes the supplier 12hrs to get enough up to us.

[chilliwilly]

In the past I have used 422 d and 407c to replace r 22, someone had been before me and retrofitted r 404a but they didn't change the oil and it wouldn't hold temperature, and the running costs had increased. R 422 d is an interim replacement and will probably be phased out after 404 a.

I heard today from a colleague that BOC are buying reclaimed 404 a, so I need to check with them to see if its true. I only reclaim if the system has a bad leak, although I am slowly realising that recharging a system with a fresh charge is probably like giving caviar to a pig, as it will be a banned substance.

Its probably more economical in the long run to retro fit, than to fully reclaim and recharge due to the short time it will be allowed to be in the system. Retro fitting is probably a better option than topping off a fractionated leftover charge, any drop in efficiency probably won't compare.

[JayeJaye]

I have been using R422A for retrofitting, mainly in ice machines, however before this I used R448A, however the supply vs demand seems to be lacking and locally the prices have been starting to rise as a result of this.