View Full Version : Looking for a moderator for this forum

12-08-2001, 10:59 PM
I am looking for a moderator for this forum.

shaun spencer
15-04-2002, 01:20 AM
and how does one become a moderator?

17-07-2002, 08:50 PM
i would like to know how to become a moderator.

17-07-2002, 10:43 PM
ah, missed these posts, sorry

What we normally do is watch people who have been posting then, approach them to see if they would like to give it a go.

We also concider requests to become a moderator, but normally wait until you have around 20 posts

18-07-2002, 03:56 AM
The first thing a moderator must do is put his foot in his mouth. The second thing is to remove the foot.

Here... let me show you how it is done.

I think that R134A is the best refrigerant for commercial refrigeration. Does anybody know that this refrigerant was developed during the 1950's?

Foot in mouth.

18-07-2002, 10:31 AM
there you go, leading by example Dan :)

Prof Sporlan
18-07-2002, 05:42 PM
I think that R134A is the best refrigerant for commercial refrigeration. Does anybody know that this refrigerant was developed during the 1950's?
Actually, a lower case 'a' sould be used here, i.e., R-134a, since is an tetrafluoroethane isomer. An upper case 'A' would indicate the first in a series of refrigerant blends with the same constituents, e.g., R-401A.

BTW, the chemical name for R-134a: 1,1,1,2-tetrafluoroethane; CAS Registry Number: 811-97-2. ARI Guideline N color designation: light blue (PMS #2975). ASHRAE 34 classsification: A1. :)

You might be interested in a refrigerant chart the Prof put together some time ago for his own amusement. http://walden.mvp.net/~aschoen/refchart.pdf

Another foot in mouth? :)

18-07-2002, 06:27 PM
Hey Dan

Better still wasn't it used to put people to sleep for the big op's like foot from mouth removal.

Even better still the sysnthetic lubricants were developed for high altitude bomber engines in WW2.

02-11-2002, 06:51 AM
ive been thinking of putting together a refridgeration system with parts, and ive been thinking of charging it with R134a. What are the prices on this refridgerant?

02-11-2002, 07:55 PM
I think it is around $3.00 and change per pound. It is one of the least expensive refrigerants available, most likely because of its high usage in automobiles and domestic refrigerators.

03-11-2002, 11:38 PM
ive called a refridgeration place locally, and they charge 7$ per pount of r-22. isnt R22 more efficent at pumping heat?

04-11-2002, 01:32 AM
That's cheap for a small quantity of R22.

Regarding the "pumping more heat" thing, it is not as simple as that. Some refrigerants can capture more heat per pound as they move through your system, but they require more work to dispense the heat, too.

What you have is not simply a compressor, but a "motor-compressor." If you take a motor-compressor that was sized for doing a certain amount of work with R12, for example, and then apply R22 to it, the motor will likely become overloaded.

A motor-compressor designed for R22 and using R12 will not produce as much refrigeration, will draw low amperage, and will likely become overheated because there is less mass flow cooling the motor.

An air conditioning motor-compressor will suffer the same sort of failure if you attempt to operate it with its original refrigerant..... but at a lower-than-design-temperature.

The limitations of a motor-compressor are significant compared to a compressor that you could run with an external motor.

That being said, most motor-compressors that work with +20 deg F evaporation temperatures designed for R12, theoretically will work well with R22 at -20 deg F evaporation temperatures.

For a while, anyway.

Like I said, it is not that simple.:)