R404a

[tjk2007]

Good Morning to all,

I need details about R-404A

To my knowledge R404A is a mixture of CFCs.


Can i know the percentage of CFCs.
Incase you detect a lekage in the R404A system you have to recharge the total system?Then it will be a costliest maintenance.
Expecting your suggetions

Regards,

TJK

[Argus]

.

No, R 404A is not a blend of CFCs.
It is a 3 part blend of HFCs and has no ODP as a result.

It has a glide in the order of 0.6 C. This is comparable to the glide of R410A and can be termed a near-Azeotrope.

In practical terms, unless you have a large critical charge, it should not be necessary to reclaim the whole charge in the event of a leak; the blend imbalance will be negligible.

All the global refrigerant manufacturers carry technical information about R404A and all the other common refrigerants on their websites.

.

[Bones74]

You can go to dupoints website or any other manufacture to get some basic info. You said in case of a leak? Are you trying to top off a blend? I wouldn't even think about it ever. You will never analyze it to find out what part of the refrigerant leaked out and even if you did. POE is a nightmare on oil and the system still needs a oil change after that. If you have a leak, scrape the refrigerant and change the oil, filter and refrigerant.

[Bones74]

How so? Curious. The blend has refrigerants in it. They operate at different pressures. On a leak one refrigerant will leak faster than another, agree? So if you top it off then didn't you just change the refrigerants capabilities? It is a new blend now.

[WINJA]

How so? Curious. The blend has refrigerants in it. They operate at different pressures. On a leak one refrigerant will leak faster than another, agree? So if you top it off then didn't you just change the refrigerants capabilities? It is a new blend now.
That maybe the theory but Ive been topping up 404a for years and have never experienced a problem , that is so far at least

[PaulZ]

Argus is correct. Because there are so many blends around don't get confused between non Azeotropic, near Azeotropic and Azeotropic mixtures as they all have different characteristics.
With non Azeotropic mixtures if a leak occurs the amount of each component that is lost is different and therefore it would be necessary to remove the refrigerant and start again.
If the system has R401A or B, R407B or C, R409A I would reclaim and replace.
I have experienced problems with a Carrier chiller on R407C having high head pressure problems from new. We reclaimed all the refrigerant and weighed it and found there was 2 kgs less then stated on the name plate. We charged the stated amount into the system as a liquid and no more problems. We suspected the refrigerant was charged incorrectly in the factory.
If the system has R404A, R408A and R410A it would not be necessary as these are near Azeotropic mixtures and the loss rate of each component is very close.
As stated by Winja he has never experience any problem with topping up a R404A system.
Hope this helps.
Paul