Quote:
Originally Posted by jroode32
I guess my first question is what do you guys think about using r290 (propane) or mx-12a (propane and butane blend) AKA Maxi Frig? I've read about as much as I could find on the topic and I don't see much if an extra risk. What do you guys think?
|
If you work with R-290, you need to know you are taking full responsibility for your own safety.
Most consumer devices that use propane have built-in safety features that we take for granted. If you defeat these safety features, you are increasing the hazard to yourself.
I first found out about R-290 from some blogs where German children were using the stuff to make extreme chillers for their video games, because they couldn't get anything else.
I have used R-290 (bar-b-que gas), and it works. There is a purity issue with it, in that the fuel grade is not 100% propane. I have tried to find info as to what the typical additional gases are, and butane is what I keep come up with.
I did see a paper written about the effect on refrigeration efficiency if there was some butane. The paper concluded that 5% to 8% butane would actually increase efficiency.
If you had a large system of several Tons capacity, and the compressor, etc. was inside the house envelope, you would be inviting very serious trouble.
In the UK they solve this problem by locating the R-290 containing parts in a separate envelope, removed a safe distance from from the house.
Working with R-290 will involve risk. I would not recommend working with it in an enclosed area, and I would advise face shield and protective clothing.
R-290 does not require as high a pressure as R-22, R-12, R 134a, or R410a.
It is compatible with mineral oil as found in R-12 and R-22 systems.
It also has a Pressure-Temperature curve that is really close to R-22, so cap tubes meant for R-22 will work pretty well.
I actually tried to braze a system that had R-290 and had leaked down... I ended up with a flame-thrower. I was lucky, and didn't get hurt... don't do anything stupid.
If you work with R-290, you will be assuming full responsibility for you own safety.
-AC_Hacker