Red Tek for A/C recharge?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Wow, didn't Helium have something to do with Hindenberg?
There is nothing mystical about a/c work. Get your license online at www.epatest.com or any of the sites at www.epa.gov and buy all the R12 you want (Autozone has been the cheapest at anywhere from $10 to $15/can - you'll need 3 for most jobs - $45 is the least you will spend on a leaking 10 to 20 year old automotive system). If you want to work on your Home Unit (and buy R22), you will have to take a proctored course, but they're readily available and inexpensive (at least in the major metropolitan areas). You will need a Vacuum Pump - If you have a decent sized compressor, buy a Displacement Pump for 9 Bucks at Harbor Freight Tools. Otherwise, you can sometimes rent one. Buy a manifold gage set - about $80 for a good one. If you are going to do a lot of this stuff; ie, your house (R22) and use different refigerants, buy dedicated hoses for each gas. Study your Service Manual for specifics about your Year - or go to any of the a/c sites run by the guys who do this for living - www.ackits.com (automotive but there are enough pros lurking around so you can post residential questions and get a decent answer) or http://hvac-talk.com/vbb (residential).
There is nothing mystical about a/c work. Get your license online at www.epatest.com or any of the sites at www.epa.gov and buy all the R12 you want (Autozone has been the cheapest at anywhere from $10 to $15/can - you'll need 3 for most jobs - $45 is the least you will spend on a leaking 10 to 20 year old automotive system). If you want to work on your Home Unit (and buy R22), you will have to take a proctored course, but they're readily available and inexpensive (at least in the major metropolitan areas). You will need a Vacuum Pump - If you have a decent sized compressor, buy a Displacement Pump for 9 Bucks at Harbor Freight Tools. Otherwise, you can sometimes rent one. Buy a manifold gage set - about $80 for a good one. If you are going to do a lot of this stuff; ie, your house (R22) and use different refigerants, buy dedicated hoses for each gas. Study your Service Manual for specifics about your Year - or go to any of the a/c sites run by the guys who do this for living - www.ackits.com (automotive but there are enough pros lurking around so you can post residential questions and get a decent answer) or http://hvac-talk.com/vbb (residential).
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
PS - If your goal is to make ice, simply eliminate the Low Pressure Switch or crank down the cutoff threshold to some number below freezing (23 psi should do it for R12 and about 20 psi for R134). At those numbers, your Evaporator will become a nice chunk of ice. Unfortunately, very little air will pass through it, so you won't be getting any cold air out of the vents. HVAC is heat absorption - not a heat transfer process.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Don't think so. Helium is an inert gas.
Interesting direction for the thread just now - we watched a Discovery
Channel episode on the Hindenburg last weekend.
The Hindenburg used Hydrogen -reportedly because access to Helium
was denied. Hydrogen is flammable and is/was widely thought that
use of this gas led to the disaster.
However, the show reported that investigation later concluded that
the 'dope' used for the skin was implicated. A few years ago,
NASA investigator Dr. Addison Bain recreated the substance and
in the show he demonstrated the bright, magnesium-light flash-fire that
samples generated. The clue for him is the nature of the flames shown
in the film of the event - the fire doesn't look like burning Hydrogen
apparently.
Anyway, here is a clip from a Excerpted from "The Philosopher Mechanic" by Roy McAlister
DVD.
.
Interesting direction for the thread just now - we watched a Discovery
Channel episode on the Hindenburg last weekend.
The Hindenburg used Hydrogen -reportedly because access to Helium
was denied. Hydrogen is flammable and is/was widely thought that
use of this gas led to the disaster.
However, the show reported that investigation later concluded that
the 'dope' used for the skin was implicated. A few years ago,
NASA investigator Dr. Addison Bain recreated the substance and
in the show he demonstrated the bright, magnesium-light flash-fire that
samples generated. The clue for him is the nature of the flames shown
in the film of the event - the fire doesn't look like burning Hydrogen
apparently.
Anyway, here is a clip from a Excerpted from "The Philosopher Mechanic" by Roy McAlister
Regardless of much speculation, translation of a letter handwritten
in German on June 28, 1937, by Hindenburg investigator and electrical
engineer Otto Beyersdorff states "The actual cause of the fire was the
extreme easy flammability of the covering material brought about by
discharges of an electrostatic nature ..." Recently, NASA investigator
Dr. Addison Bain has verified this finding by scientific experiments that
duplicated the vigorous ignition by static discharge to the aluminum
powder filled covering material. Spectacular colors of this type of
combustion were produced from the burning skin of the giant airship.
Dr. Bain concluded that the Hindenburg would have burned and crashed
even if helium would have been used as the lifting gas. Dr. Bain noted
that the particular type of aluminum powder particles, which are flake
like in shape, are particularly sensitive to electrical discharge.
The DC show was pretty interesting, check your library for a tape orin German on June 28, 1937, by Hindenburg investigator and electrical
engineer Otto Beyersdorff states "The actual cause of the fire was the
extreme easy flammability of the covering material brought about by
discharges of an electrostatic nature ..." Recently, NASA investigator
Dr. Addison Bain has verified this finding by scientific experiments that
duplicated the vigorous ignition by static discharge to the aluminum
powder filled covering material. Spectacular colors of this type of
combustion were produced from the burning skin of the giant airship.
Dr. Bain concluded that the Hindenburg would have burned and crashed
even if helium would have been used as the lifting gas. Dr. Bain noted
that the particular type of aluminum powder particles, which are flake
like in shape, are particularly sensitive to electrical discharge.
DVD.
.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Then for the love of Sophia, wear eye protection.
A family friend of my parents operated an HVAC business and lost his
eye-sight in an industrial accident involving an apprentice, an unexpected,
discharge of refrigerant and lack of eye protection.
This was in the e-60's, IIRC. As a result of the accident, Harry was in
on the pioneering work done in the field of various kinds of laser
surgery, including corneal transplants. If he were here today, he'd
have stories to tell.
.
A family friend of my parents operated an HVAC business and lost his
eye-sight in an industrial accident involving an apprentice, an unexpected,
discharge of refrigerant and lack of eye protection.
This was in the e-60's, IIRC. As a result of the accident, Harry was in
on the pioneering work done in the field of various kinds of laser
surgery, including corneal transplants. If he were here today, he'd
have stories to tell.
.
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
My opinion, for what it is worth, and it has already been mentioned, is don't use a blend -- regardless.
Blends have components with molecules of different sizes.
And, when the compressor isn't running to keep the blend mixed, the components tend to separate, which can cause the smaller molecules to leak faster than the larger molecules.
Presto, the blend is no longer the same blend.
And, you can't top it off (well...you could if you determined the percentage of each component left in the system and used a calculated blend of different percentages to counter the offset of the original blend) -- you have to evacuate it and start over to get the same blend.
Plus, some of the components, when separated, are more flammable than the blended components.
Stay with R-12 or R-134a.
Tom Piper
Blends have components with molecules of different sizes.
And, when the compressor isn't running to keep the blend mixed, the components tend to separate, which can cause the smaller molecules to leak faster than the larger molecules.
Presto, the blend is no longer the same blend.
And, you can't top it off (well...you could if you determined the percentage of each component left in the system and used a calculated blend of different percentages to counter the offset of the original blend) -- you have to evacuate it and start over to get the same blend.
Plus, some of the components, when separated, are more flammable than the blended components.
Stay with R-12 or R-134a.
Tom Piper
Last edited by Tom Piper; Feb 27, 2007 at 07:00 PM.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
One time for fun I pulled a hose on an overcharged R12 system. To this day I can't recall why I thought it was a good idea. It blew oil everywhere and froze all the air in its path, for what seemed like 2 minutes.
