Can Freon be added?

[theterrells]

I was just told by a local RV repair shop that freon cannot be added to Coleman rooftop A/C. I mentioned an add-on schrader valve and he said that it didn't matter, if the unit was low on freon it had to be replaced.

Is he "full of it" and just trying to sell a new unit or is he correct?

Floyd Terrell
71 23' Land Yacht
Saraland, Alabama

[idroba]

You can add refrigerant to any rooftop unit, but it must have a valve to do it (sounds like yours has had one put on). Take it to a refrigeration place and they can do it. However, it may not be economical, especially on an older unit which apparently has already been repaired in the past.

[Aerowood]

Most of the rooftop air conditioners do not have the high and low pressure fitting and are not designed to be serviced but replaced. You my find a shop to do it, but if it's low on coolant there is a reason it has leaked out and that would have to be fixed also, soooo most shops will not take the liability to service them. Like many things is the USA today it is a disposable item, just like a window A/C unit is.

This is the reason I want to install an over the road truck sleeper / ambulance type split unit in my trailer. They are completely repairable and serviceable units, the cost is approximately 2.5 times as much as the throw away units that have become so popular today

[Inland RV Center, In]

Originally Posted by theterrells

I was just told by a local RV repair shop that freon cannot be added to Coleman rooftop A/C. I mentioned an add-on schrader valve and he said that it didn't matter, if the unit was low on freon it had to be replaced.

Is he "full of it" and just trying to sell a new unit or is he correct?

Floyd Terrell
71 23' Land Yacht
Saraland, Alabama

Any rooftop AC that has ever been on any Airstream, can be fixed.

If it's low on Freon, theres a leak.

The leaks can be corrected.

If there are no high or low pressure fittings, the manufacturer saved a few dollars.

But,(b)Line-A-Taps(/b) are sold everyday by any AC parts house.

That is all that's needed to add Freon.

Andy

[shelocta]

Floyd;
This video is about window ACs but everything is applicable to a rooftop RV unit. This video basically reinforces everything that Andy said. The fellow on the video is a little rough around the edges so if you're offended by cuss words don't watch. I think his information for the most part is accurate and his warning about fhosgene gas should be taken seriously. I'm not sure how the EPA feels about end-users working on their own systems and I don't think I'll ask.
Reguads
Bill

How to fix window airconditioners - YouTube

[lewster]

Just a few 'hints' on re-charging a modern RV roof A/C.................

• These units are hermetically sealed at the factory for a reason. If they thought it a good idea to re-charge them like a domestic unit, there would be a pair of Schrader valves soldered into the high and low sides of the refrigerant lines.
• Anything can be repaired.........but what is the real cost? After all, just about anything can be done......it's just a question of time and money.
• Clamp-on piercing valves (which are required to evacuate the refrigerant lines) are OK for just that purpose, but left in place, they will leak and MUST BE REPLACED with silver soldered permanent Schrader valves.
• the proper process for the re-charge on a sealed unit is as follows:

1. apply 2 piercing valves
2. evacuate the system with a vacuum pump and certified recovery
cylinder
4. silver solder permanent Schrader valves into the high and low sides
5. pressurize the system and check for leaks (this is why you started this in
the first place)
6. locate and seal any system leaks
7. purge the system with nitrogen
8. using the proper equipment, re-charge the system to the requirements
listed on the specifications label
9. If you're lucky and no corrosion or scale from your soldering operation
becomes lodged in the capillary tubes, the unit will probably cool again...
but for how long?
10. There is no warranty for the work you just had done, while you get a 2
year warranty with a new unit.

• You need a federal license to handle refrigerants (especially R-12 and R-22)
• It is a federal offense to knowingly release refrigerants containing CFCs of HCFCs into the atmosphere, carrying a $10,000 fine per occurrence!

The above is the reason that the major RV air conditioner manufacturers no longer support this methodology. Most RV techs no longer have the equipment, training, skills and licensing to do the job properly. I have an ARI Universal refrigerant license, but still wouldn't apply the above process on any RV air conditioner............but if you feel that you have the expertise and qualifications....GO FOR IT........YMMV!!

[HowieE]

Consider replacing the unit now if you can still get one with #22.
The next generation of ACs will have a new refrigerant that run with head pressures over 500 psi. These unit will draw much more current for the same out put and while you are not paying the electric bill in the campground it may limit your use of other electrical equipment with your 30 amp service.

[lewster]

Originally Posted by HowieE

Consider replacing the unit now if you can still get one with #22.
The next generation of ACs will have a new refrigerant that run with head pressures over 500 psi. These unit will draw much more current for the same out put and while you are not paying the electric bill in the campground it may limit your use of other electrical equipment with your 30 amp service.

Howie, they are already here.......using R401-C and now R410-A. I've already had to replace 2 relatively new units that appeared to have leaks and low compressor amp draw, but the data plates of the new units compare almost identically to the older units for amp draw for compressors.

[Aage]

Do the old Armstrong units have high and low Schrader valves?

[lewster]

Originally Posted by Aage

Do the old Armstrong units have high and low Schrader valves?

I don't work on them but I believe they do, as they came that way from the factory. THey were designed for repair, not replacement in the early days.

[Aage]

Curious why you don't work on them, Lew...?

[overlander63]

I can't answer for Lew, but I can tell you why we don't. Those units are now in the 40+ year old range. I can fix the unit today, then two weeks from now something else will fail. The customer will want it fixed for free. Then, two months later, something else may fail, and again the customer will want it fixed for free. The choice at some point becomes subsidizing the customer's air conditioner, or possibly losing the customer if we refuse to continue fixing it for free.
Any shop can only do this so long for so many units before making a policy of not repairing them.

[theterrells]

Thanks for all your help!!!

I had an A/C man come out and check the unit, he said at 40 years it is time to replace. So, that's the way I am going.

Ordered a new Coleman Mach 15 last night.

Thanks again

Floyd Terrell
Saraland, AL

[lewster]

Originally Posted by overlander63

I can't answer for Lew, but I can tell you why we don't. Those units are now in the 40+ year old range. I can fix the unit today, then two weeks from now something else will fail. The customer will want it fixed for free. Then, two months later, something else may fail, and again the customer will want it fixed for free. The choice at some point becomes subsidizing the customer's air conditioner, or possibly losing the customer if we refuse to continue fixing it for free.
Any shop can only do this so long for so many units before making a policy of not repairing them.

YOU ARE SO RIGHT ON THAT!!!!!!

Took the characters right off my keyboard (updated version of 'took the words right out of my mount!)

[Inland RV Center, In]

Originally Posted by Aage

Do the old Armstrong units have high and low Schrader valves?

Only low, which is usually at the back end of the AC.

A proper working roof AC, should kick up the high pressure, to 4 times the low pressure.

As an example, if the low is 70 psi, the high should be 280 psi.

A good indication of a worn out compressor is when the 4 times, starts dropping, to even 3 times.

That's a positive indicator that the compressor is worn out.

Compressors don't last forever.

Andy

[Aage]

Thanks for the info, Andy and everybody. I really don't understand AC repair, and would therefore not attempt it myself.

For example, how do they test the high pressure to calculate the ratio if there's no valve. Is there some other way of knowing the high pressure?

[Inland RV Center, In]

Originally Posted by Aage

Thanks for the info, Andy and everybody. I really don't understand AC repair, and would therefore not attempt it myself.

For example, how do they test the high pressure to calculate the ratio if there's no valve. Is there some other way of knowing the high pressure?

The only way you can know the pressures, is by a meter.

Tapping into a line, is therefore a must.

Andy

[Haoleman]

I was in the appliance service business for 30 years. Learned long ago that unless you can hear the leak, you will spend more time looking for it than the unit is worth. That's why we would just add gas and tell the customer if it continued to work, great but if it went down again, it was time to replace the unit. Warranty? Yes. Terms? Good till the dust settled in the driveway! That was in the days when we would dump the charge into the air