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914World.com _ 914World Garage _ OT any HVAC guys on here?

Posted by: seanery Jun 7 2004, 05:56 PM

My A/C needs a recharge. I bought some refrigerant a couple years ago when my uncle was up here visiting. He had his gauges and refilled the system. I watched him do it, and remember a bit, but not all.

Can anyone give me a brief how to?

this is a home, not a car system by the way.

thanks in advance

Posted by: ! Jun 7 2004, 06:34 PM

Most FLAPS have the fitting that goes on the cans.....it has a screw top with a puncture thread.

"I" would consider having it pressure tested first....those hoses are known leakers and the old style refrigerant is more expensive than a Supermodel on a coke binge.....

Most a/c guys that still do old style a/c will use a cheap gas....IF you ask them.....like propane or such.....so that you can save the expensive stuff for later.

You will more than likely have to repalce the hoses. Best place for custom barrier type hoses are places that do hydraulic hose crimping for tractors and trucks......

Posted by: seanery Jun 7 2004, 06:45 PM

I have the old style refrigerant, bought a big container-looks like a proprane tank. The gauges are coming soon. I just can't remember the procedure.

Posted by: ! Jun 7 2004, 07:53 PM

All ya need is the hose that connects to the inlet.....run it up to 20 psi and test it....

Posted by: seanery Jun 7 2004, 07:56 PM

cool, i knew it was`simple.

Posted by: Joe.D Jun 7 2004, 08:12 PM

Actually, I think its now illegal to use freon without proper recovery equipment. The very high price, and the very limited availability reflects the intent to discourage its use.

But, if you have some, and the right tools, and intend to try to charge the system yourself, you should first make sure the system has no leaks so what you put into the system stays in the system

You probably have a 2 manifold gauge set - one for a "high" and one for a "low" range of pressure.

The high side reading is used to monitor the pressure after the compressor.

Connect these to the ports near or on top of the compressor. Then, use a vacuum pump to evacuate the system through the low side.

You fill the system by bleeding freon gas, NOT LIQUID into the low side as the compressor is running. Keep the hose from the supply bottle on the top, to be sure you don't introdduce liquid freon into the compressor.

Low side pressure should be around 35, high side around 150, and will cycle up and down as the compressor kicks in and out.

There is usually a sight glass somewhere in the system (often on top of the reciever/dryer). As you fill the systems you will see cloudy white flow across the sight glass. When you don't see white flowing across the glass anymore, the system is full enough.

I'm not an HVAC engineer, but I have done this quite a few times over the years. Even so, I'd get a professional to do it. And offer to trade whatever is left from the bottle of Freon as payment for the service call. :-)

Joe

Posted by: Kerrys914 Jun 7 2004, 09:12 PM

PLEASE be careful..

I am sure your gauge set will have 3 maybe 4 hoses. Blue (low side), Red (high side), and one or two yellow (service lines).

Make sure you RED valve is CLOSED when you are charging the system. Check it 2-10 times. The pressures can explode the tank/can and kill you.

The tank/can gets connected to the yellow line and the blue and red get connected to the suction and discharge lines.

You mentioned you were low on charge. Do you have a leak or is it just not blowing cold air. No sense adding more charge if it will just leak out agian.

The charge pressures are dependent on the ambient temperature. The ones listed are a good range but if its really hot or below 70 you need to adjust the pressures some.

Best of luck
Kerry

Posted by: seanery Jun 8 2004, 05:09 PM

OK, that was pretty easy.

Grainger manifold gauges $68
picked up my R-22 from my dad's house
called my uncle (the pro)

and a half hour later the A/C is recharged and cooling the house!