questions on using duracool in US cars... - Page 2 - PeachParts Mercedes-Benz Forum

babymog · #1 04-21-2011, 09:28 PM

It is above it, but there is a chimney through the evaporator/boiler that takes the heat around and above the rest of the coils.

I don't really understand all of the plumbing on the back of these things, I have had a couple go bad in my buses over the years, pull them out and there are lots of steel tubes running around on the back of the cabinet.

Fortunately they went to household side-by-side referigerators in buses back in the '90s, but most RVs still use the ammonia systems so that they can cool without electricity using the propane flame.

I understand that there was a lot of ammonia used in commercial refrigeration also until fairly recently.

Orv · #2 04-22-2011, 02:27 PM

Quote:

Originally Posted by babymog

It is above it, but there is a chimney through the evaporator/boiler that takes the heat around and above the rest of the coils.

I don't really understand all of the plumbing on the back of these things, I have had a couple go bad in my buses over the years, pull them out and there are lots of steel tubes running around on the back of the cabinet.

http://en.wikipedia.org/wiki/Absorption_refrigerator

There's some interest now in using batch-cycle absorbtion-refrigeration systems as A/C systems in cars. The idea is to use waste engine heat to power the process, instead of taking power off the crankshaft.

Quote:

I understand that there was a lot of ammonia used in commercial refrigeration also until fairly recently.

I wonder how much of the switch had to do with toxicity concerns, and how much was due to all the problems they've had lately with meth-heads stealing the ammonia?

layback40 · #3 04-21-2011, 09:30 PM

Propane or other similar hydrocarbon mixes as refrigerants do not have the cooling capacity of F12 or other freons.
the ammonia system mentioned is a water/ammonia mix in an absorption system, completely different process.
best stick to what your aircon was designed to use.

leathermang · #4 04-21-2011, 09:37 PM

Babymog, what I was trying to get to was that on these other refrigerants they are often NOT placed at the very front of the vehicle ( like our condensors ) and thus NOT subject to being released during very minor crashes...

babymog · #5 04-21-2011, 10:23 PM

Quote:

Originally Posted by leathermang

Babymog, what I was trying to get to was that on these other refrigerants they are often NOT placed at the very front of the vehicle ( like our condensors ) and thus NOT subject to being released during very minor crashes...

Got it. I guess that is a bit of a tangent anyway.

Personally, as long as R-12 is available, I'll stick with it.

sjh · #6 04-22-2011, 01:17 AM

If I can stop thinking about Cindy Crawford I'll jump in.

I don't think ammonia is very flammable; dangerous, reactive, toxic, sure but I don't think it burns, but I've been wrong before.

My AC system is great. I knew about the early refrigeration systems that ran on ammonia but was not aware of units based on hydrocarbons (HC). It made me curious. So I went to the duracool site and the EPA site.

As others have commented a number of static systems run on HC. But the EPA bans the usage in non-static applications. Then I read some more and found a number of folks writing about how successful they have been in running their auto AC on HC.

I wondered a bit about having 18 oz of HC at ~ 15 atm under the hood. I've made some very simple calculations (tried not to screw them up) and concluded that 18 oz of butane (using that as the worst case example) in the AC system if it ignited would release the same amount of energy as burning about 1/6th of a gallon of gas.

Since 1/6th of a gallon of gas moves my car about 5 miles (on the highway, your mileage may differ

) I've decided that was a lot of energy and the consequences of a mistake are too great to make the thought of putting in an auto attractive.

Now, back to Cindy Crawford!

WDBCB20 · #7 04-22-2011, 10:18 AM

Here we have a manufacturer that has been equipping its vehicles with hydocarbon refrigerants:

http://www.hydrocarbons21.com/content/articles/2010-12-09-world-s-first-oem-chooses-hc-refrigerant-for-vehicles.php No one got hurt

Here we have a comprehensive scientific assessment of usage and risk of hydrocarbon refrigerants in vehicles: http://www.hychill.com.au/pdf/usage_risk_mvac.pdf

"The actual accident frequency and hence risk of using hydrocarbon refrigerant
in motor cars is much lower than predicted when commercial use commenced."

Here's the famous porsche 928 sliced refrigerant hose underhood episode, the perennial favourite trotted out by HC fearmongers : http://www.youtube.com/watch?v=k0K1WPCWm2k Yes it burns.

And here's the video of researchers blowing themselves up in simulated worse case scenario - emptying HC refrigerant straight from the can into the passenger compartment and lighting it with an open flame:

http://www.youtube.com/watch?v=k0K1WPCWm2k

Yes it explodes as do gasoline (what most cars in the US run on)vapors.

Hope this serves as an antidote to the hand-wringing pontifications of armchair doomsday hypothesizers long on talk short on fact i.e. real world evidence.

leathermang · #8 04-22-2011, 11:23 AM

Quote:

Originally Posted by WDBCB20

Here we have a manufacturer that has been equipping its vehicles with hydocarbon refrigerants:

http://www.hydrocarbons21.com/content/articles/2010-12-09-world-s-first-oem-chooses-hc-refrigerant-for-vehicles.php No one got hurt

Here we have a comprehensive scientific assessment of usage and risk of hydrocarbon refrigerants in vehicles: http://www.hychill.com.au/pdf/usage_risk_mvac.pdf

"The actual accident frequency and hence risk of using hydrocarbon refrigerant
in motor cars is much lower than predicted when commercial use commenced."

Here's the famous porsche 928 sliced refrigerant hose underhood episode, the perennial favourite trotted out by HC fearmongers : http://www.youtube.com/watch?v=k0K1WPCWm2k Yes it burns.

And here's the video of researchers blowing themselves up in simulated worse case scenario - emptying HC refrigerant straight from the can into the passenger compartment and lighting it with an open flame:

http://www.youtube.com/watch?v=k0K1WPCWm2k

Yes it explodes as do gasoline (what most cars in the US run on)vapors.

Hope this serves as an antidote to the hand-wringing pontifications of armchair doomsday hypothesizers long on talk short on fact i.e. real world evidence.

I hope THIS SERVES as an antidote for a collection of half assed concepts accumulated to your post ...

First idiot statement :
"Yes it explodes as do gasoline (what most cars in the US run on)vapors."

Show me ONE VEHICLE which has gasoline exposed at the FRONT of the vehicle with as little protection from minor accidents as does a condensor.

Second Idiot statement :

"The actual accident frequency and hence risk of using hydrocarbon refrigerant in motor cars is much lower than predicted when commercial use commenced."

What difference does that make ? Someone might have been overly concerned about safety and it caused them to estimate a higher risk factor ?

If this were a FAIR world... and someone ...anyone ... followed your suggestion that hydrocarbons are fine for use in their AC... and one of those ' lower than expected ' accidents causes injury or death to one of their family members ... they should come and find you and take justice right out of YOUR HIDE. Perhaps also that of your family members...
But this is not a Fair world... so if they are injured .. and get this next word carefully --- UNNECESSARILY ---- it will not be any skin off your back... no monetary penalty.. no nothing....and as I suspect someone who would encourage these UNNECESSARY RISKS has no conscience and would therefor not lose any sleep over news that people's lives were affected adversely.
There are safer alternatives which work just fine for our cars...

Matt L · #9 04-22-2011, 10:23 AM

Quote:

Originally Posted by sjh

As others have commented a number of static systems run on HC. But the EPA bans the usage in non-static applications. Then I read some more and found a number of folks writing about how successful they have been in running their auto AC on HC.

A rather large number of static applications exist, with propane as the design refrigerant. Replacing that HC refrigerant with 134a would result in reduced performance for the same reason that replacing your 134a with propane won't work very well. Well, really the opposite reason, but the root cause is using something other than the design refrigerant.

The EPA does not ban HC's for mobile AC. A fair number of states do ban it outright, but what the EPA bans is a direct conversion of R12 to any HC. You have to have a "genuine" conversion to a non-CFC first. I think it's a very silly restriction, but it is there and the penalties are stiff.

sjh · #10 04-22-2011, 11:00 AM

DOT does not allow duracool or other HC-based refrigerants in autos.

I had listed the wrong acronym previously.

As stated above the EPA also bans putting duracool in a system approved for R12.

IMO asking and thinking about safety is a good thing.

leathermang · #11 04-21-2011, 09:59 PM

YAK, THAT WAS A VERY GOOD OVERVIEW OF THE SITUATION !!!!
Particularly mentioning the oil miscibility .. which can be more of a problem on a compressor with NO oil SUMP like ours...