dr bob

Hmmm, there are some who look at long-term sunspot activity and identify global temp trends over periods longer than human carbon conversion has been pervasive. At least from somewhere north of the discovery of fire. But this isn't a political forum. I was pointing out that the R-12 ban is hardly world-wide.

On to your problem. Currently, US auto AC shops tend to be equipped to handle R-12 and R-134a only. Converting to R-134a doesn't require you to replace the compressor if the shaft seals are intact, but you will want to flush the old oil out and replace it with a synthetic R-134a compaitible lubricant. I lean towards the polyolester lubricants because they don't turn to jelly when they come in contact with residual mineral oil remaining in the system. Of course, if you do a complete solvent flush of the system as part of your conversion effort, you can use any of the available lubricants.

Perhaps in the next few years we'll see new vehicles equipped with sealed systems based on hermetically sealed electric compressors, and therfore have rigid piping and no leaky junctions. Kinda like a lot of commercial refrigeration systems. The electric car trend may drive some of this too, since folks will want to have AC even when there's no gas motor spinning a belt. Once that happens, we'll likely see ammonia-based systems come back into vogue, since the basic nitrogen and hydrogen components in ammonia have not yet been linked global warming trends or ozone depletion. We just need to study that issue more though; there's massive anecdotal evidence that global warming has happened in the presence of massive amounts of atmospheric nitrogen. We just need to identify the link.

UKKid35

It would be very comforting if this were indeed the major contributor, and in fact more research is moving the argument in this direction. But who knows whether it is truly independent.

Dr Sami Solanki, the director of the renowned Max Planck Institute for Solar System Research in Gottingen, Germany says it is the major contributor in a report released today according to the London Telegraph

Mark Stahl

You write this as if it were something extraordinary and not already part of the integrated understanding of climate change that is emerging. It's not new, nor is it generally considered to be an effect of sufficient magnitude to account for the observations.


Well, at least you understand that you were making a political, and not a scientific, point. That's a start.



So as long as one sticks with R12 or R134a, all is well? Sounds good. Thanks.



In my searching for replacement bits I've already seen a number of purely electric compressors for sale... I figured that was how the hybrids and electrics worked anyway. Of course, one never knows what will happen when the associated patents expire...


Well played

Mark Stahl

Not to argue, but in the interest of, you know, accuracy, it should be noted that Solanski didn't say that. At all.

From the article you posted:
"Dr Solanki said that the brighter Sun and higher levels of greenhouse gases, such as carbon dioxide, both contributed to the change in the Earth's temperature but it was impossible to say which had the greater impact."

Though this is a new-ish study and perhaps its exact numbers aren't fully incorporated into everyone's thinking, the variations in solar output over time are a well-known phenomenon that was originally thought to be the main driver of global climate change until they couldn't account for the changes in the 20th century.

Podguy

Dr. Bob,

Part of any agreement is the supression of non-conforming information. In the case of the Ozone layer which this year made a remarkable recovery - the smallest hole over Antartica since they have been measuring the thing - all of the reseach came from one corporate funded scientist. Subsequent reports were published off his work, so no one bother to duplicate his experiments.

A group of scientists recently found trees and other plants release methane - lots of methane. These are living trees - not dead ones. The Krebs cycle does not consider methane as part of the plant cycle. As a greenhouse gas Methane is many times worse than CO2 yet trees have not suddenly decided to give of Methane. They have been doing it for years. So where does the methane go? Better yet how did Methane end up on Titan?

No matter. Would ammonia be such a good idea for cars. Ammonia is deadly. I remember in the old days when we wanted to get a compressor out of an old refrigerator we would drag the thing into a field, crack the pipe and run away. Come back the next day and all the grass around the refrigerator had died.

One interesting trend I notice is the virtual banning of Laquer thinner in the auto body trade. Yet there is no restriction of cabinet and furniture makers. You can whip down a piece of furniture with laquer thinner but it is illegal to apply any laquer thinner to any automotive metal. The substiture is acetone. You can also buy all the laquer thinner you want at Home Depot or even Kragen.

Can someone explain why new paints with an acetone base are ok and laquer thinner is bad. Looking at the ingredients in the new paints and the precautions taken when spraying them, they sure appear to be far more deadly than the old stuff.

Dan the Pod Guy

dr bob

Dan--

Ammonia is a very efficient refrigerant. But DuPont and GM/Frigidaire didn't have patents on ammonia. Tough to corner an open market commodity. Ammonia is corrosive when there's water around, more so than freon that's for sure. Key I think will be the availabilty of truly sealed package units, with no hoses and no compressor shaft seals. With eth compressor assy mounted rigid to the body, no need for hoses, and the compressor can be mounted anywhere the plumbing needs it to be. In addition, ammonia lends itself very nicely to use in absorbtion chiller units with no moving parts. If anhydrous ammonia wasn't so darn tough on lungs when it leaked out, it would kick butt on freon in rankine systems.