r502

[kryptobs2000]

My choices of refridgerant are 404a or propane right now, but my dad has some r502 as well, and looking at a spec sheet of it, it looks better than 404a to me, but I don't know what alot of these are. Never heard of it being used in a single stage pcer tho.

http://www.protocolresource.com/R502.asp - 502

http://www.protocolresource.com/R404a.asp - 404a

[Ssilencer]

I used r502 in my systems, it has better boiling temp than r404

[Redwolf]

502rules

[wdrzal]

502 is a cfc and under the clean air act production was halted dec 31 1995.its being phased out like all other cfc's r11,r12,r13,r113,r114,r500,r502 & r503 walt

[Ssilencer]

wdrzal, ask chilly1, Redwolf, Bowman, etc what do they think about the clean air act...
Just another comercial act...

[wdrzal]

I would agree,it just forced everyone to buy expensive recovery equiptment based on disputed science. refrigerants used to be about $1.00 per pound before it. walt

note :its note illegal to use cfc's just the price got so high no one will use them, a 30lb. can of 502 is about $1200.00

[craig588]

wow...I just picked up some R404a at what I thought was a great deal at 20$ a pound.

*dreams of 1$ gasses*

[kryptobs2000]

wow 1$ a pound lol. That is nice, and that is *was* the standard price too. I got alot of 502 for free tho, so now I'm sure it's good, I'll gladly use it. How does it compare to 404a and 507? I'm pretty sure it's a bit better than 404a, what about 507? Better than that too? If so, I got a sweet deal, not sure how much my dad has, but he's got plenty.

[Redwolf]

507 gets a degree colder than 502.... however with 502 you can use TD150 Alky oil instead of that POE crap we're stuck with.

[wdrzal]

134a was $2.00 lb just a few years ago

[Ssilencer]

Sorry for the offtopic, Redwolf, what do you think of R402 working with mineral oil?
I heard that r402 works with mineral, other people recomended alky, and another Poe.
Do you have any experience with r402+mineral oil?
I'm building a system with r402 now and I will be using a 1/3hp comp. but it has 2 different models with the same displacement but one with mineral (for r12, so cheaper comp.) and the other with Poe (for r134, so more expensive one)

[Redwolf]

I prefer Alky TD150 oil with any Low Temp application. However R402A (HP80) does work with mineral oil too. The 2% of propane helps to keep the oil moving.

[kayl]

does anyone know if 502 has much capacity compared to say r404a?
thats the real question. boiling point isnt everything.

i think that from memory bowman said that 502 is high pressure gass and he added some r22 i think for better pressures, read it a while back though so memory foggy.

[kryptobs2000]

I don't know much about gasses other than boiling points, and I did look at those two links provided, and from what I took of it, 502 is lower pressure than 404a, which I think is a good thing right?

Could I get a few explanations of diff. facotrs of refridgerants performance maybe some examples too, or even just a link that explains it? :) :) :)

[LostInSpace278]

The molecular weight of 404a is 97.60 and boils at -46.6. psia of 542.
The molecular weight of 502 is 111.63 with a boiling point of -45.3 with a psia of 583.

The way I have seen it stated is the heavier the molecualr weight is the better capacity it has.

[kryptobs2000]

What effect does capacity have on temps?

[LostInSpace278]

It can with stand varying heat loads with a lil less drop in temps.

[kayl]

The molecular weight of 404a is 97.60 and boils at -46.6. psia of 542.
The molecular weight of 502 is 111.63 with a boiling point of -45.3 with a psia of 583.

The way I have seen it stated is the heavier the molecualr weight is the better capacity it has.

I think it molecular weight x density to work our capacity.
Im not good at this stuff we need Russell hg hes good at this stuff..

[LostInSpace278]

Hmmm, I haven't came across a doc with densities on it yet. I'll go searching for one though.

[chilly1]

IN 1991 when I started my business up in MAine R12 was 26.00 for a 30 LB cylinder R502 was 32 and 22 was 30. And the Clean Air act is like the cigarrette lawsuits all designed to increase federal revenue.

[gkiing]

wow, the same r12 today might go for $300+

[chilly1]

the same R12 today is 1200.00 cost to manafacturer not including all the "New Taxes on the industry" about 20.00 per 30.lb cylinder... taxes 1000.00 including all teh "Enviromential taxes" So who profits?

[wdrzal]

the same R12 today is 1200.00 cost to manafacturer not including all the "New Taxes on the industry" about 20.00 per 30.lb cylinder... taxes 1000.00 including all teh "Enviromential taxes" So who profits?


Can r12 still be manufacutured in usa. I thought the only supply came from r12 the was reclaimed and remanufactured(filtered for purity). No one ever fixed leaks back then they just top it off. in the the 80's I would fill my freinds a/c in car, about 1 to 2 pounds and just say buy me a beer when you see me.cost was .70 cents a pound. Now if you charge a car you need to ask for their paycheck.I started in 1981 and remember 22.00 for 30# that included the disposible cyclender too. Walt

[kayl]

they still use r22 here is australia, and lots of it, i think its due to be end in 2010

[wdrzal]

Still here too, it is the cheapeast to buy,the last purchase I made was 64.00 for 30#

[kayl]

r22 is cheapest here too. i think like half price of 507,404a etc
ya need a license and have reclaim unit etc,
need all the gear plus trade qualifications (4year cousre/trainging)
i wish i had a license though could have some betta gases

[chilly1]

R22 is subject to a risizing tax schedule like R12/502/11/ etc.

[wdrzal]

R22 is subject to a risizing tax schedule like R12/502/11/ etc.

Yep,They want to stop its use too,R22 is great for central air and other medium temp applications.

[Unknown_road]

the same R12 today is 1200.00 cost to manafacturer not including all the "New Taxes on the industry" about 20.00 per 30.lb cylinder... taxes 1000.00 including all teh "Enviromential taxes" So who profits?

weird rules indeed. In many european country's these refrigerant are realy banned. no matter what you pay you don't get them

[wdrzal]

In a few years the "ice man" may be a common sight again :D :D :D

[saratoga]

the same R12 today is 1200.00 cost to manafacturer not including all the "New Taxes on the industry" about 20.00 per 30.lb cylinder... taxes 1000.00 including all teh "Enviromential taxes" So who profits?

I think they banned R12 manufacture in the US 7 or 8 years ago. I don't even think theres a tax on making it, just if you do they throw you in jail, which is why its so expensive.

[kryptobs2000]

if it's illegal to make, why would it be legal to buy?

[wdrzal]

They relize that a lot of it is in use in expensive refrigeration equiptment and not eveyone can afford,or is willing to change it all at once.So by not allowing manufacture of virgin freon,only existing supplies and remanufactured (filtered from recovered)freon is available,the reduced supply along with the greatly increased enviromental tax will cause the price to rise to the point were it is cheaper to upgrade and replace their equiptment than to pay $40.00 a pound for refrigerant. Walt

[chilly1]

Actually production is limited to quotas. it was reduced a bit a year. There is still a supply of recycled R12,502,11 etc available here in the states. The only things illegal are selling it with out paying tax and venting it.

[Russell_hq]

I ran a comparison of various gases to find out which offered the most promising qualities.

I used R290, R22, R404a, R502, R507a, R410a. Never used R402 as I wasnt aware of it at the time.

From the results, it would seem that R507 would be the best choice with regards to capacity and condensing pressure.

You can look at the graphs here;

Condensing Pressure vs. Temperature (http://www.russellpetrie.plus.com/images/autocascade/GasComparisonPT.gif)
Capacity (kJ/m3) vs. Temperature (http://www.russellpetrie.plus.com/images/autocascade/GasComparison.gif)

The first graph used saturation conditions at various temperatures. For the second, I used heat of vaporisation (kJ/kg) * gas density (kg/m3) at saturation conditions. This gave me an idea of how much heat could be absorbed per m3 of gas boiled off. As I believe that specific volume is an important factor when comparing because the compressor pumps fixed volumes of gas and not a fixed mass.

This was just a quick exercise to give a rough idea on the various gases.

[kayl]

QUOTE=LostInSpace278]The molecular weight of 404a is 97.60 and boils at -46.6. psia of 542.
The molecular weight of 502 is 111.63 with a boiling point of -45.3 with a psia of 583.


I think it molecular weight x density to work our capacity.
Im not good at this stuff we need Russell hg hes good at this stuff..

thanxs russell hq i knew ya come up with the good stuff. :shrug:

[LostInSpace278]

I'm not to good at computing this stuff in my head. My brain is like a 233 Mhz processor some days. I look at some of the formulas and :slobber: . It's mind numbing. I wouldn't mind having that program the Russel has though :stick: Seems pretty sweet.

[kayl]

I ran a comparison of various gases to find out which offered the most promising qualities.

I used R290, R22, R404a, R502, R507a, R410a. Never used R402 as I wasnt aware of it at the time.

From the results, it would seem that R507 would be the best choice with regards to capacity and condensing pressure.

You can look at the graphs here;

Condensing Pressure vs. Temperature (http://www.russellpetrie.plus.com/images/autocascade/GasComparisonPT.gif)
Capacity (kJ/m3) vs. Temperature (http://www.russellpetrie.plus.com/images/autocascade/GasComparison.gif)

.



russell_hq could you when ya get a chance have a look at this charge and add care50/hc22/502 to this chart.
i want to print it out.
not sure if this info would help
http://www.xtremesystems.org/forums/attachment.php?attachmentid=15907
and

[Russell_hq]

Im not sure what you mean kayl. I R502 is already on it. Are you wanting a separate line for the other 2. Just refresh me, is Care 50 Propylene and whats hc22?

[kayl]

the refrigerant that i use is called hc22/502 is a blend of r290 and ethane
another hydro carbon refrigerant that’s use to be around was called care 50.
it too was a blend of r290 and ethane.
the refrigeration document for care 50 should be the same as hc22/502 i hope.
hc22/502 is the replace meant for both r22 and r502.
they call it hc22 (hydrocarbon) / 502 replacement.
this is a really good spec sheet for it, was wondering if you would process it for me.

http://www.refrigerants.co.kr/html/prodtechinfo.htm

:cheer: :party: