Our dash air still works (sorta). It loses freon and I can't figure out where it is leaving. Added dye and so far no help. Anyway the system was R12 which I changed to R134 and now thinking R152. Was going propane until I found some info on R152. Anyway, has anyone used this refrigerant? If so what were the results.

Curious why you want go to R152, not readily available in the US and more costly than R134a. It is a greener refrigerant but is it worth cost? Just don't have any leaks. R152 has a bit higher discharge Temperature a bit harder on the compressor and I assume you are using your R12 compressor.

When I have not been able to see dye marks it is usually in the evaporator or condenser core and hidden to the eye. Good luck!!

R152 is Difluorthane. Available all over the place, just not in automotive supply stores. It is DUSTER gas and used to clean electronics. Available at Walmart for about $6 a can. Ebay runs about $5-7. R12 provided a colder temp than R134 and R152 is colder than R12. Some of the Youtube videos show output temps in the 30s.

Now I would never condone an argument but!!! What else can we do in the Covid infested, freezing midwest!! lol

R152 at condensing temperatures above 50C has more cooling power than R134a, below that range R134a wins. Engine RPM does seem to affect cooling power a bit.

Searched Amazon, eBay and Walmart could not find R152, things must be different in Arizona and Minnesnowta... Did find a medical R152 spray. With a bit of finagling and repackaging I suppose one could get that into a refrigeration system from a spray can? Or you freeze off a wart!!!

I would be remiss if I did not say the COP (coefficient of performance) is better with R152. This is the ratio of power in (Gasoline) vrs power out (BTU)!


3.1 Cooling Capacity
Figure 3 shows the cooling capacity for R134a and
R152a for various condensing temperatures. The
cooling capacities of R134a and R152a are
represented by continuous and dash lines,
respectively. It can be seen that the cooling capacity
of R152a is lower than that of R134a for the
condensing temperature of 40oC and 45oC. However,
for the condensing temperature of 50oC, the cooling
capacity of R152a is higher than that of R134a. The
cooling capacity improvement is shown in Figure 4.
Figure 3 The cooling capacity vs. rpm for R134a and R152a
Figure 4 The cooling capacity improvement vs. rpm
Figure 4 shows that at the condensing temperature
of 40oC and 45oC the cooling improvement is
negative. It means that at those condensing
temperatures, the cooling capacity of R152a is lower
than that of R134a. Also, at those condensing
temperatures, the cooling capacity improvement
slightly decreases with the increase in engine rotation.
The cooling capacity improvement of R152a occurs at
the condensing temperature of 50oC. At this
condensing temperature, the cooling capacity
slightly increases as the engine rotation increases. For
example, at 1000 rpm, the cooling capacity
improvement is 4.7% and increases by 5.0% at 3000
rpm.

Sorry it would not let me copy the charts. 50C is about 122F. Rare to find condensing pressures over 175 PSI for a R134 or R12 system. So I guess if one were to modify or get a less efficient condenser and increase the operating pressures one could make R152 a more powerful source of cooling, the price of course is wear and tear on the compressor. Probably affect gas mileage a bit also.

see!!! what you started now .

Blame it on the COVID !!!!!

What are the pros and cons of propane/hydrocarbon? They are cheap and environmentally friendly... The mfrs don't like that they are flammable but unless you get a massive dump there is no real fire hazard. Not so great with the old style propane torch leak sniffers though!

How do they compare with the halogenated hydrocarbons, ie fluoro and chloro carbons?

Not trying to argue, just looking for the coldest refrigerant. R152 is Difluorethane and sold as duster gas. Walmart https://www.walmart.com/ip/onn...aner-10-oz/315452914

You then get a can punch Napa 78-1009

Also would like the web site for the charts.

Originally was going to go with propane and I still might. Not nervous about using it. The propane for the cook stove is more dangerous. Except for the evaporator all the a/c lines are outside.

Found the charts and rethinking. Now looking at R290 (propane) and R600 (propane butane mix). Might just use propane. Problem is the stink oil that is added to it. Don't know if that would hurt anything or not. Have the advantage of stinking if leaking.

One of the causes of a/c leakage is using R134 in systems designed for r12. They are a much smaller molecule. Propane would bring back bigger molecules.

Anyway don't need it till next summer.

There is a brand called Envirosafe which is a hydrocarbon blend (don't know the R number). Comes in cans like 134 so easy to use with standard AC recharge equipment. It has no odor but it does contain a UV dye for leak detection. It is cheaper than 134. I used some to recharge my old 05 Sable and it seems to cool very well. Not sure if it is the best choice but it is an old car so I figured I'd give it a try. So far I am happy with the performance and price.

One of the problems with the old R12 systems was the hoses. They were cheaper and more porous than the ones used in 134 systems. When the industry converted from 12 to 134 they upgraded to much better hoses. As you mentioned, the 134 molecules are smaller and the pressures are a bit higher, hence the higher leakage.

This problem is worst in a rear engine coach. Long hose runs from the compressor on the engine to the evaporator in the front allow a lot of leakage. I had considered converting my coach to 134 but given the expense and hassle of replacing the long hoses, and the fact the dash air was never very good, I abandoned the system.

I use the diesel generator and the roof ACs on the road and they work way better than the dash air ever could.

Agree with professor Steve, the only thing dash air does in my Nose is blow cool air on ones face! My fans do that a lot cheaper. Nose does not have air nozzles from the heater box, it has a separate system in the center of the dash.

Here is the requested link, also has lots of opinion and data.

Also not having the compressor and those awful brackets all over the engine make maintenance much easier.


https://www.researchgate.net/p...a%20up%20to%205.0%25.

hope it works!

Back in the olden days, I had an Engineer that told the welders and silver soldiers that the molecules were smaller and they would have to be a lot more careful. What a bunch of malarkey, in my humble opinion. The odds of a path that would let R134a thru and not R12 must be about a billion to one!

Duane, I think leakage has little to do with molecular size and more to do with time and temperature. On a hot day after mowing the lawn the much larger average molecular size beer will leak out of my bottle faster than my scotch. Conversely the scotch with a smaller average size molecule seems to disappear more often faster at lower temperatures. One might argue about the dependence on light and dark scales of each and those effects on this postulation. It being the lunch hour I am opting for an exception to my postulation, a light beer, predominately of 18 weight molecules.

quote:

Originally posted by ccctimtation:
Duane, I think leakage has little to do with molecular size and more to do with time and temperature. On a hot day after mowing the lawn the much larger average molecular size beer will leak out of my bottle faster than my scotch. Conversely the scotch with a smaller average size molecule seems to disappear more often faster at lower temperatures. One might argue about the dependence on light and dark scales of each and those effects on this postulation. It being the lunch hour I am opting for an exception to my postulation, a light beer, predominately of 18 weight molecules.

Very good analysis. Wonder if dark or light beer makes a difference and 21 year old Scotch seems to go down easier than 12 year old scotch. Just saying

Nick

Error correction, average molecular weight of scotch is greater than beer but density is lower.

Based on many experiments with leakage, this much I know: I pee more when I drink beer instead of Scotch...