PDA

View Full Version : R407C v R404A


CJG21
17-08-2010, 10:39 AM
I've heard recently M&S have been trialling R497C as a replacement for R404A in some of their stores.

Can anyone explain the benefits of using R407C? It looks to have a lower head pressure at condensing temp, are ther others?

What have been the results of such a move and are M&S looking to go down this road instead of CO2?
Sandro Baptista
17-08-2010, 11:35 AM
Can anyone explain the benefits of using R407C? It looks to have a lower head pressure at condensing temp, are ther others?


Yes, lower head pressure and also more environmental friendly (or on reality less enemy :) ) ... but very very zeotropic, lower COP, less capacity...Personally I don't like R407C.
Grizzly
17-08-2010, 06:14 PM
And an absolute bitch to leak check.
Grizzly
Sandro Baptista
18-08-2010, 08:37 AM
That's right Grizzly.

The R407C blend is very "fractionatable"...so if a leak occur on the vapour state...hmmmm... :(
CJG21
18-08-2010, 08:46 AM
Great, so until this supposed 'super gas' gets the go ahead then we have to deal with CO2 :(
coolhibby1875
18-08-2010, 10:33 AM
co2 seems to be the way forward, as for 407c you will lose your charge quickly even through the smallest of leaks!
CJG21
19-08-2010, 11:14 AM
Do you not think CO2 is a flash in the pan coolhibby? I only know a bit about it and have only seen one plant (Tesco/Star), however the pressures are crazy and an accident is waiting to happen.

Surely the du ponts of this world wont stand by and watch their profits fall as co2 is so much cheaper? Will they not try to develop a new gas with low gwp/odp?
Aik
19-08-2010, 12:24 PM
...but very very zeotropic, ...Personally I don't like R407C.
R407c has very big glide 7.1K (R404a - 0.7K). I also dislike it.
Guy Hodgins
27-08-2010, 11:52 AM
I think you will find it is 407A they are trialling, not 407C. The benefits are all environmental. It has a lower GWP and absorbs less power for the same refrigeration effect.
CJG21
02-09-2010, 12:33 PM
Ok, have any findings been released yet? Does it suffer from the same problems that 407c suffer from listed above?
Guy Hodgins
02-09-2010, 01:09 PM
it can suffer from the same problems but none that are yet found to be real show stoppers. The lower GWP is known and published but the figures on energy reduction are not fully quantified, but should be at least 5%.
Mark
02-09-2010, 03:06 PM
R407A is Quite a common alternative from R404A which is being used in its place.

However, R407D is being used as well but I have not worked with this Long Term yet?
Guy Hodgins
02-09-2010, 04:08 PM
Not used this one yet. However, as all the 407 variants simply change the percentages of the three constituent refrigerants perhaps with fractional leakage you could start with A and end up with D!
Blueboy
18-09-2010, 08:26 AM
R407a is being run out my Morrisons M&S and Waitrose. Its a great gas for supermarket packs so long as it's set up correctly i.e. New R22 expansion valves and the pack operation pressures set up.

Its fine to leak check and I have not had any addition leaks caused by it yet , I have looked at about 20 sites with it on