Propane/isobutane for Freon replacements
George Goble
propane/isobutane to replace R-12 in an automotive aircond
(it worked fine). If anybody wants to see that, I can repost it.
Jgd, check out this month's "ASHRAE Journal" (June 1991), it has
an article titled "Why not propane?".
The author proposes propane/isobutane (like I used) to replace R-12
in cars, and also in large buildings and supermarkets. He wants to
work on safety codes and practices to allow flammable refrigerants.
May be that it is easier than the "eco-nazi" track the gov't is now
following with respect to refrigerants?
As I suspected, the author, Daniel Kramer, did testing that showed
propane can be used as a "drop in" for R-22 with about a 10%
capacity loss. A blend of propane/propylene would match R-22
exactly (propane/isobutane for R-12 match). R-502 could also be
handled (a little more propylene). All being hydrocarbons, have
no oil miscibility (refrigerant and oil dissolve in each other)
problems with common mineral compressor oils.
Once, for the hell of it, I tried mixing in Halon-1201 in with
the propane/isobutane mix, to see if it would supress the flammability,
but it took 50% or more of the mix to be halon to do any good
and halon is 3X-10X the ozone depleation of R-12.
I wonder what it would take to keep a large propane leak in the
compressor pit at a large supermarket from turning into a
BLEVE? Halon or other fire systems? Very large refrigeration
systems have "receivers" (tanks) which would behave like propane
"tanks" in a fire since they may hold tens of gallons of the gas
in liquid form.
--ghg
Don T. Borowski
post it here.
BTW, there was an editorial about the use of propane as a refrigerant in the
September issue of "Electronics World + Wireless World" (a British electronics
magazine). The point was made that given the volume of a typical kitchen
and the amount of propane that would be needed in a typical refrigerator, the
mixture would be way to dilute to burn (explode), even with statification.
Plus, taking into account the most refrigerant leaks are very slow, the
dilution is even more pronounced.
Their theory was that the new refrigerant being cooked up now are amoung other
things a good way for the chemical companies to make money. Much easier to
make money on some new refrigerant at $20 per pound as compared to something
common like propane at $.20 per pound.
Donald Borowski Hewlett-Packard, Spokane Division
"Angels are able to fly because they take themselves so lightly."
-G.K. Chesterton
George Goble
>Yes, I'm interested in the info on propane mixes for refrigerants. Do please
>post it here.
>
>BTW, there was an editorial about the use of propane as a refrigerant in the
>September issue of "Electronics World + Wireless World" (a British electronics
>magazine). The point was made that given the volume of a typical kitchen
>and the amount of propane that would be needed in a typical refrigerator, the
>mixture would be way to dilute to burn (explode), even with statification.
>Plus, taking into account the most refrigerant leaks are very slow, the
>dilution is even more pronounced.
I posted it yesterday..If you missed it, I can email it to you.
A home fridge would only need 3-4 oz of propane (probably propane/isobutane
blend). About a year ago, I heard UL did a test on a fridge with
R-152a (difluoroethane) refrigerant, which is approx the same
flammability as propane. They put in ice-pick in the evaporator to
make a big leak, then closed the door. They had a "robot" open it
30 sec or so later. The door switch "sparked" and ignited it, blowing
the entire door across the room. This was obviously a "contrived"
case. I heard last week that UL "approved" butane for home fridge
use?? I don't know the details. Maybe new designs have smaller pipes
so they only have as much as a lighter refill can??
Check out this month's ASHRAE Journal, it has an article, "why not propane?"
>
>Their theory was that the new refrigerant being cooked up now are amoung other
>things a good way for the chemical companies to make money. Much easier to
>make money on some new refrigerant at $20 per pound as compared to something
>common like propane at $.20 per pound.
You said it! Look what happens if the "big boys" are able to block
new R-12 substitutes (for cars), except R-134a which takes a whole
new system. Then they get to sell you a $1200 new A/C for your old
car or even better, sell you a whole new car! (with $20/lib R-134a)
>
>Donald Borowski Hewlett-Packard, Spokane Division
>"Angels are able to fly because they take themselves so lightly."
> -G.K. Chesterton
--ghg
Don T. Borowski
Yeh, the stuff about the UL test of the refrigerator is a real crock.
First of all, you would have a hard time even finding the evaporator
coils on most modern refrigerators. I could not hit the coils in
mine with an ice pick if I tried.
Secondly, the light switch and
thermostat switches could easily be designed to either seal the
electrical contacts or place the contacts in the outside air.
Then about the only way you could get the things to blow up would be
to throw a lighted cigarette on the floor in front of the refrigerator
and then open the door. I do that all the time, and I'm sure you do too.
It seems to me that natural gas is more of a hazard in homes than any
hydrocarbon based refrigeration would be.
One last question. A lot of propane is sold with an oderant mixed in to
give it that "gas" smell (since the stuff has no smell of its own). Does
that cause any problem in refrigeration systems?
Donald Borowski Hewlett Packard, Spokane Division
George Goble
>hydrocarbon based refrigeration would be.
Natural gas/propane to gas appliances are an "unlimited" supply, so
if a bad leak happens, one fills up the basement with it, and no more house.
Fridges can be designed to run on 8oz of R-12 easily, this translates into
about 4 oz of propane/isobutane. About as much as in a large butane
lighter filler can. A central air system would need about 2.5 lbs, a car
needs about 1.5 lbs max. "War-mongering" companies are all overhyping the
flammability issue, since hydrocarbons have no ozone depletion, they need no
recycling equipment, and cost $.20/lb, so there is no money to be made.
They would rather sell you $25/lb R-134a + $4000 recycler for CFC/HCFCs,
and then another $4000 recycler for the R-134a (which does not deplete
ozone). Flammability range for propane/butane/isobutane is around
2% - 8% in air.
>One last question. A lot of propane is sold with an oderant mixed in to
>give it that "gas" smell (since the stuff has no smell of its own). Does
>that cause any problem in refrigeration systems?
The isobutane I used to create this thread had the "propane" odorant,
probably a few ppm of some mercaptan. It worked fine. It was "pure"
grade (98%). THe "pure" grade isobutane I got from Phillips-66 (99%)
has no odorant, and has almost no smell. It is being used for another
refrigerant project. A lot of propane is "wet", which may cause
the expansion device to freeze. Don't use "hamburger gas" grade
propane, unless you can dry it out. Propane is listed as refrigerant
R-290, Butane is R-600 and isobutane is R-600a.
I just heard that Florida will (does?) have a state law which requires
repair shops to either fix an A/C leak or pump out all the Freon
before the car can be allowed to leave the shop. No more topping
off the leakers
--ghg
>
>Donald Borowski Hewlett Packard, Spokane Division
>"Angels are able to fly because they take themselves so lightly."
> -G.K. Chesterton
--ghg
Mike Smith
>In article <440...@hpspkla.spk.hp.com> boro...@hpspkla.spk.hp.com (Don T. Borowski) writes:
>>One last question. A lot of propane is sold with an oderant mixed in to
>>give it that "gas" smell (since the stuff has no smell of its own). Does
>>that cause any problem in refrigeration systems?
>The isobutane I used to create this thread had the "propane" odorant,
>probably a few ppm of some mercaptan. It worked fine. It was "pure"
>grade (98%). THe "pure" grade isobutane I got from Phillips-66 (99%)
>has no odorant, and has almost no smell. It is being used for another
>refrigerant project.
The propane is liquid in typical propane tanks. The mercaptan has
no problems volitalizing in normal use. There should be no problems
from the few ppm used in terms of volitalization. I think mercaptans
are also rather chemically stable, but even if they did attack the
guts of the system, a few ppm isn't going to corrode much ...
>A lot of propane is "wet", which may cause
>the expansion device to freeze. Don't use "hamburger gas" grade
>propane, unless you can dry it out.
How does one determine if their gas is 'wet' or not? Is
"hamburger gas" what I buy for my backyard gas BBQ from Amerigas?
>I just heard that Florida will (does?) have a state law which requires
>repair shops to either fix an A/C leak or pump out all the Freon
>before the car can be allowed to leave the shop. No more topping
>off the leakers
How do they define a 'leak'? One can in a month? A year?
Visible leakage? Driving in with an empty system? Visible
dye spot after waiting an hour? A day?
--
E. Michael Smith ...!sun!apple!ems
'If you can dream it, you can do it' Walt Disney
This is the obligatory disclaimer of everything. (Including but
not limited to: typos, spelling, diction, logic, and nuclear war)
Don T. Borowski
I suppose what this means is that if you come in complaining that the
air conditioning doesn't work, they can't just top off the charge and
let you go your merry way. They have to either find the leak and fix
it, or empty your charge. And I suppose that the same requirements
would hold if you drove in with some other complaint, and they noticed
that the air conditioning wasn't working or was leaking.
Donald Borowski Hewlett-Packard, Spokane Division