Frigiking rooftop a/c

[Supurcar]

I read on another thread about someone buying a used a/c unit for around $140. I need one so I went hunting at my local wreckers. I found a couple of them, one place wanted $250 and they had a bad attitude. The thing was out of a 1972 wrecked R/V and looked dirty. Needless to say I passed on that one but it was a coleman.

I found another place more reasonable in a mid 70's larger R/V, it looked like the crew used it as a break room as there was a table set up and a bed made up and ready for a nap, it was in the junk yard lol.

So this R/V had a frigiking a/c and they wanted $150 for it; I took off the shroud and it had the mounting kit kind of like steel box sleeves for the square cut out- and they looked like a good fit. It was dusty but no more than the cabin a/c I have now normal use I am sure. It was also hard wired and had a box and steel tube for the wires to run through to the coach wiring and two switches. There is no way to test the thing so I am looking to get some input from anyone who has done this, or am I better off finding a new one?

[Bodybagger]

Remove the plastic cover from the interior of the AC. Open the electrical connection box.

Wire an electric cord to the black and white wires and the green to the ground screw.

Then plug it in and try it out.

If you cannot reach it with an extension cord, you'll have to remove the whole AC unit and take it to an outlet.

[futar]

One thing to remember is that the older ones have the old freon in them in case it needs to be recharged. The new freon requires higher pressures although I did a conversion in a car and it worked okay. Don't let a service person fool you. There's plenty of the old freon available from Mexico and it is inexpensive.

[Bodybagger]

I think they are talking about a rooftop AC unit. Hermetic compressor AC units manufactured within the last 50 years through the end of this year use refrigerant R-22 with very very few exceptions. Some packaged air conditioners (as in rooftop, window, or wall models with hermetic compressors) used R-12 in the 1950s and 1960s but an R-12 packaged AC is by far the exception and not the rule. The only one I have run across was a Firestone window air conditioner made in the 60's.

Beginning January 1, 2010, no new AC units will be manufactured for use with R-22. They will mainly use refrigerant R-410a instead. However, R-22 will still be produced to service existing units.

Beginning January 1, 2020, all production and importation of R-22 will be banned, and recycled supplies must be used. Even then, R-22 itself will not be banned.

One of the main disadvantages to R-410a is the extremely high pressure it runs at. It runs over 100psi on the low side and over 400psi on the high side. An R-22 air conditioner CAN NOT be retrofitted to R-410a because it would explode at these pressures, if the compressor didn't burn up first.

As of today, R-22 is running about $200 per 30lb cylinder.

[Maineah]

One thing to remember is that the older ones have the old freon in them in case it needs to be recharged. The new freon requires higher pressures although I did a conversion in a car and it worked okay. Don't let a service person fool you. There's plenty of the old freon available from Mexico and it is inexpensive.

If you are talking about R12 be very careful with cheap R12, propane works quite well as a refrigerant and most of the cheap stuff out there is propane R12 was priced off the market years ago there is still some around but it's not cheap. The roof top is most likely is R22.

[Supurcar]

Thanks for the feedback. That frigiking was too old and is no longer making rooftop a/c units (for about 20 years). It actually looked clean but I did not want to risk it not working and the price was too high.

I actually went a different route and tried some shade netting around the perimeter of the RV and it worked quite well. Most of the heat comes thru my large side windows which get burning hot to the touch. And the over cab area does not have as much insulation as the rest of the RV. I clipped a 6 foot by 14 foot wide section to my luggage rack and to the ground along the sun facing side of the RV; it reduced the heat by about 70-80%. I just had to move it when the sun changed angles but the netting kept it comfortable inside and it was about 89 degrees outside. In temperatures above 95 degrees it may not be as effective. I just fabricated up a quick test when we camped two days ago, I am going to add to the design and make an "L" shape to go around the front (or rear) and sun facing side. It also gave a bit of privacy at night.