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Thread: R22 vs R404 differences
05-08-2012, 11:44 AM #1
R22 vs R404 differences
So I recently started working for my father, who sells walk-ins and condensers. He said R22 refrigerant is starting to become phased out because of the increasing cost and harm to the environment so he said he is going to stop selling R22 and move to R404 instead.
I'm just wondering, what are the main differences (if there are alot) between R22 and R404?
05-08-2012, 12:55 PM #2
Off the top of my head, 404a is a blend not compatible with mineral oil. Runs at lower pressures and can fix capacity issues in old systems.
Not a drop in replacement.
05-08-2012, 02:18 PM #3
05-08-2012, 02:24 PM #4
BTW..., if you check your PT chart you'll see that pressures are a bit higher than R22 at the same saturation temperatures.
The primary driving force to cause a switch from R22 to R404A in commercial refrigeration system today is probably cost. As the cost of R22 increases, the price of R404A has come down significantly. Many of us in this business made that decision some years ago simply because R404A is in many ways a much better refrigerant.
One very big plus is R404A runs at much lower discharge gas temperatures, meaning the compressor and its oil are a lot cooler at the same conditions. That translates to greatly improve compressor life expectancy since the oil isn't being cooked to the point of breaking down and slowly killing the compressor.
Another advantage is R404A works equally well on low, medium or high temperature applications...so one refrigerant for all. I like that immensely.
05-08-2012, 02:24 PM #5New Guest
- Join Date
- May 2012
- Dillsburg, Pa.
R404 is a better A/C refrigerant because of the lower temps but works like R410 in heating. The discharge temps are lower than the normal for what an R22 system would see. The new dry R22 units have mineral oil in them so they are already compatable with R404. Many are starting to use that since the price of R22 is getting bad.
05-08-2012, 04:55 PM #6
Looks like I have a lot to learn because I didn't understand most of what you guys meant but I guess I did notice that R404 is used for cooler and freezer condensing units but I haven't seen any R22 freezer units yet.
05-08-2012, 05:16 PM #7
But one issue I see with what you suggest is no manufacturer of dry units (that I'm aware of) has approved R404A for use in their units...ie, no warranty.
Another thing I'm concerned with is how would you properly select the expansion device required? For example, if the system has a fixed orifice, the orifice flow capacity must be nearly double that of R22...and I doubt there are any charts out there to tell you the right one to use.
I would think a much better solution for dry units with R22 compressors containing POE oil would be to use R407C as long as the manufacturer allows it. I know that R407C is now an approved R22 substitute in dry units from Nordyne...there may be others.
05-08-2012, 06:25 PM #8
It will work, but it has some issues, namely high discharge temperature that can lead to oil breakdown.
R-404a has been used in low temp applications for quite some time, now, so I don't expect you'd see too many R-22 freezers.
05-08-2012, 06:33 PM #9
05-08-2012, 09:19 PM #10
05-08-2012, 09:21 PM #11Professional Member
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- Nov 2008
- Altamont, IL
Ice is right as usuall R404 for all. I thought that us Ref. Techs had it all sorted out R404 would be our refrigerant!!!! But Iv'e learned that the big BOX stores (WM) are requesting R410 A So Copeland is complying and doing the work to supply Compressors rated for R 410A service ( OH NO) I hope the coil manufactureres are able to comply alsoIn GOD We Trust
05-08-2012, 09:36 PM #12
05-08-2012, 10:24 PM #13Professional Member
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- Jun 2003