Subject: Air Conditioners
From: Nancy Eilers-Hughes
Date: 9/24/03 12:35 PM Central Daylight Time
Message-id:

Earl,

FYI, you need an EPA Section 609 certification to purchase small
quantities of R-12. You can get certified (like I did) at:

http://www.imaca.org/training.htm

The cost is $15.00, and if you already understand A/C (like me)
then the whole thing takes about and hour, tops. They were very
good to deal with as well.

Wow. Only $15.00. I understand A/C, own a set of gauges, and own an electronic
leak detector. New house air-conditioner needed a refill every spring as the
tech from the guarantee only had a flame/color leak detector and could not find
the small leak. Guarantee ran out, (they said) so rather than fight city hall I
bought a good electronic leak detector, found the leak, brazed in some new
connectors, and refilled the system. End of 'springtime problem'.

Earl


For R-22, you need an EPA Section 608 certification. You can get
that, online, at:

http://www.escoinst.com/Certification.htm

Have no experience with these folks, though, so I'm NOT
recommending them, just passing on the info. Cheers,

Keith Hughes

GASNER wrote:
Subject: Air Conditioners
From: Don W
Date: 9/16/03 11:25 AM Central Daylight Time
Message-id:

GASNER wrote:


At room temp., (i.e., haven't been running it for an hour), the pressure

will

be the vapor pressure of the stuff at that temp. (IF it is not so low on

fluid

that there is no fluid at all left). You have to look up somewhere what
the
vapor pressure of each is. (I used to know, but that was a long time ago.)

That is correct. If you have a thermometer you can also connect your gages
and
measure the temperature at the evaporator and the condensor with the system
running. Most gages have temperature indicators for different refrigerants
such
that you can read the low side and high side temperatures directly.
Believe
me,
its is hard to mistake R12 for R22, because the pressures are much
different.

I think that the stuff for cars is the one with the least pressure for a

given

temp since it is so damn hot under the hood of a car.

Actually, automobiles used to use R12 which as you stated has a lower vapor
pressure than R22. For example, at 100 degrees F R12 is at ~115 PSI, while
R22
is at ~200 PSI. R502 at 100F would be ~215 PSI.

Since 1996 autos sold in the USA use R134A. R134A at 100F is ~124 PSI
which
is
higher than R12, but much lower than R22 or R502.


I have gauges and an electronic leak detector, and I would fix my freezer,

but

. . . how do people get freon today without a licence?

(Not that 'I' would do it if it were illegal. Just wondering about how

'other'

people do it.)

Earl

Well, you can buy R134A without a license at auto parts stores. There is a
non-controlled
R22 replacement marketed as (I think) Puron. According to my home AC man
there is also now
a non-controlled drop-in replacement for R12, but I don't know what it is
called.

What is in your freezer?

Don W.


Wow. I have to drop by an automotive store and check.

My freezer is just an ordinary home food freezer, ca 10/15 years old. Slow
leak. (Starts to run and compress, then cuts out. Probably a low pressure
safety.) If I could get a couple of cheater connectors I could gauge it.
and
put in some more freon. As is I probably can find the leak with my
electronic
leak detector. Perhaps seal it with epoxy, perhaps braze it.

Dirty little secret is that it should run with just adding some of the
'wrong
kind' of freon. Perhaps not as efficient.

Earl