Mp-39

[PAXFREON]

Is anyone else experiencing high head presasure in the summer montyh with this gas? I try to weight all my charges in. It seems every unit I charged worked fine until the outside temp reach 85f plus..I've have not had this problem with any other refrigerants

[Gary]

Do you check subcooling and superheat, or simply weigh it in and walk away?

[Andy]

Hi
in my experience most drop in refrigerants have increased head pressure due their designs.
1/they condense at higher pressures anyway, necessitating high side safeties and controls to be set higher.
2//drop-ins usually increase the system capacity in the evaporator, leading to a higher total heat rejection to the condenser, effectivly under sizing you condenser.
Hope this helps, regards. Andy

[herefishy]

Hi PAX,

Are you utilizing this refrigerant in a "stock" Tecumseh condensing unit. I reference my P-T chart, and see that it is about the same saturation as R-409A. If you call Tecumseh and ask them, they'll probably tell you don't use it !! they don't have enough condenser area, admittedly.

You may wish to replace with R-416A (as long if it is a medium temp application - BTW Andy, 416 actually runs lower pressures @ saturation than R-12 ). I doubt you are having this problem with a low temp application, but if you are, you would wish to employ R-414B - that HotShot stuff you see advertised. I guess R-414 is the best all around drop-in R-12 replacement, so far.

see ya'

[wesmax]

Is anyone else experiencing high head presasure in the summer montyh with this gas? I try to weight all my charges in. It seems every unit I charged worked fine until the outside temp reach 85f plus..I've have not had this problem with any other refrigerants

Most here have had high head in the hottest summer mo the most common gas dropin here is RS24 or R414, problem with R414 is a lot of R22 in it so later on it will still have to be changed.
wesmax

[Temprite]

Do you check subcooling and superheat, or simply weigh it in and walk away?

Hello Gary.

Sorry to drag up such an old thread but I have this problem with units that were once on r12.We use sp34e which is similar in composition to isceon49 I believe.

Have checked the subcooling on these systems before and is always high.If you charge to a lower subcool then the refrigerant control doesn't feed properly, as others say the condensers seem undersize.

Does anyone know of a way to combat this?

[chemi-cool]

Hi Temprite,

All those dropin's are not delivering the goods.
I've been playing with a few and it wasn't the same.
There are no shot cuts, if you stop using R12, change the system and get the results you want.

Chemi

[terrygoodrich]

I had to limit the inventory in my trucks so we stock R-414b only. This replaces 12, 134a and 500. The cost is comparable to MP-39 or R-409a. These replacement refrigerants may produce a higher head pressure, but this shouldn't be a concern. According to Copeland, the discharge temperature is the critical issue. Compresser overheating is what leads to failure. Head pressure is only one element that determines the discharge temperature. Type of refrigerant, suction superheat, and compression ratio also factor into the equation. The last factor is the only one affected by an increase in head pressure and the effect is much less dependent on a change in head pressure than suction pressure. Bottom line... don't worry about the head pressure if that is your only concern.

[wesmax]

To carry on with this I will say nobody will use MP39 here or 409 both are not good head pressure is just one thing I have heard is a problem.
wesmax

[chemi-cool]

I just wonder if and when the manufacturers will wake up from that nightmare and we will use again the good old R-12, R-22 and R-502 and R-11....................



Chemi

[PAXFREON]

I've been using 416-A for about 5 months now and absolutely enjoy working with this juice... I now carry in my van 134a, 404a and 416a.

[terrygoodrich]

Don't worry... the choices will narrow. R-134a and 407c will be available for several years for old R-12 and R-22 equipment, but I think R-404a and R-410a will become the most common refrigerants. All others will eventually go by the wayside. As R-22 is phased out, so to will all the R-12 replacements be history.

[wesmax]

I Do Not Think R12 Replacements Will Ever Be Gone And I Hope They Dont Stop Making Them . As For R410 Here It Is Going To Be A Long Time Comming Except In New Packaged Equip
Wesmax

[PAXFREON]

Don't worry... the choices will narrow. R-134a and 407c will be available for several years for old R-12 and R-22 equipment, but I think R-404a and R-410a will become the most common refrigerants. All others will eventually go by the wayside. As R-22 is phased out, so to will all the R-12 replacements be history.

That my friend is long time away.

[wesmax]

I Have Worked In Sales And In Wholesale Area For Years . This Last Year In The Company Where I Work The Company Has 9 Branches And Sells Millions In Ac Units And Not One Ac In 410 And Only Sold One 30 Lb Cyl Of The Gas. One Other Thing Some Of The Dropins Have A Lot Of R22 In Them So They Will Be Gone Soon Because Of The Blend.
Wesmax

[PAXFREON]

I hear you have to upgrade your vacuum pump and gauges when working on 410 equipt...thankfully I haven't came across it yet.