Home » Public Forums » GMCnet » [GMCnet] R-22 roof air - its over my head...
| [GMCnet] R-22 roof air - its over my head... [message #213099] |
Wed, 03 July 2013 00:16  |
 |
ljdavick
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma:
|
Senior Member |
|
|
I thought I'd try to shoot the Duracool 22-A into the roof air on the coach. To my surprise when I took the shroud off the unit I saw that there already is a saddle tap on the low pressure side so the one I bought seemed unnecessary. The threaded fitting was a different size, so I screwed the new tap on as well. With two low pressure taps and a high pressure stub coming out of the compressor I thought I'd be able to hook up my gauge set and use the Duracool supplied gauge. Unfortunately the service label was faded to oblivion, so I have no idea how much R-22 the unit was designed for.
I pulled a vacuum for only a few minutes. Sadly there was refrigerant in the system when I began to draw it down. I only used my cheap Harbor Freight vacuum pump (the one that hooks up to a compressor) and my gauge set, on the already installed low and high ports, showed a vacuum.
I started putting in the Duracool R-22a to get an initial charge (per instructions). Waddling my bulk down the ladder I fired up the Onan so that I'd have plenty of voltage, and then turned on the air conditioner.
As the Duracool flowed into the low side and the gauge set swung up to about 20 psi I saw the pipe freeze up. After only a moment it thawed. I finished the first can and saw 30 lbs on the low side and 140 on the high side. Remembering the dash AC I thought perhaps I had overcharged the system and began to bleed off some Duracool. No luck - she kept blowing warm - all the way down to about. 12 psi.
I began to realize that I'm an idiot who knows little more about hvac than how to spell it. Acknowledging this fact is liberating. I now began to add the second can because I no longer needed a reason, and saw the low pressure hose begin to freeze at about 30 psi. I continued until I had 37-40 low and 170 high.
It's much cooler than it was, but I really have no idea what I'm doing. Its only about 68 degrees with the outside air at 80 I had such great luck with the dash air because others had gone before and showed me the way. I believe the roof air to be a nice unit. It's an Intertherm Polaris 13.5k btu unit with a heat strip. It has a scroll compressor and looks to be very well designed. A few cans of Duracool, if it works, and some stop leak might just get me through a few summers. By then hopefully Carrier will be back in the game and I'll have landed into a pot of gold.
I know there are AC experts here, and I know this is an oddity. Speculation is free! Am I on the right track, and the fact that I bled off so much Duracool prevented a happy ending? Is it likely that there is some internal blockage and the best thing to do is cut my losses and buy a block of ice? Could anyone speculate as to what low pressure I should look for? Any suggestions are appreciated.
Larry Davick
A Mystery Machine
Fremont, CA
1976(ish) Palm Beach
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
|
|
|
|
Current Time: Wed Oct 09 06:15:18 CDT 2024
Total time taken to generate the page: 0.01312 seconds
|
GMCforum
Search
Help
Register
Login
Home
