Community Forums

pajeeper · 03-22-2012, 04:34 PM

Does anyone know how many lbs. / ozs of freon does the 2005 Fleetwood Discovery C-7 Cat. take for the A/C system ?

Bug512 · 03-22-2012, 07:39 PM

Take a look where the blower motor / evaporator is. You might find a sticker showing the amount.

I'm not by a computer else I would try to google it.

PandK · 03-22-2012, 08:00 PM

I had a similar question on mine (Rexhall on a Spartan chassis) when the filter failed and released the refrigerant. On mine I found the A/C (dash) was installed by the coach builder not the chassis manufacturer. My system was supplied by Evans/Tempcon and after a LOT of searching I found a table showing the approximate system capacity. Turned out the estimate was very accurate.

KIX · 03-22-2012, 08:05 PM

An A/C tech can determine the correct quantity by gauge pressures.

RinkersRanch · 03-22-2012, 08:50 PM

Quote:

Originally Posted by KIX

An A/C tech can determine the correct quantity by gauge pressures.

Sorry, I don't want to step on toes, but, you can't accurately fill an R134a system using only gauges. A system built in 05 will have R134a and not R12 in it. I taught automotive A/C from 1990 (when this R134a stuff came out) to 2007 and did many experiments with charging R134a systems. The result was, . . Fill it with the proper amount (by weight) and the vent temp should be at least 20 degrees F above ambient temps. DO NOT ADD THAT LITTLE EXTRA. R134a works better at a slight undercharge. (1-2 oz..) It will not cool well at all with a 4 oz overfill. As long as the gauge readings are within range for a given ambient, that is all you can do. Believe me I wanted to prove I could charge these systems using gauge pressures. Well this 'new' refrigerant made a believer out of me. I did R12 A/C service for 20 years before this new stuff came out and I was very determined to prove the 'experts' wrong. Well I was shown wrong by my own tests and experiments. Use a scale, fill, check the dash vent temp. Should be at least 20 degrees F below ambient when on Normal A/C fan on High. (NOT MAX or RECIRCULATE) R134a acts nothing like, pressure gauge wise, R12 in an operating system. I can add a lot of fuel to this fire with 17 years of playing with this stuff. One last thing. . . .
Never let anyone tell you an R134a system will not get as cold as an R12 system. I have charged several systems to blow air 30 degrees below a 90 degree F ambient temp. R134a systems are also much more sensitive to high humidity. It really drives up High side pressures.

This is not going to help you find the correct charge. But you can use this information to interview prospective service facilities.

KIX · 03-22-2012, 08:55 PM

Quote:

Originally Posted by RinkersRanch

Sorry, I don't want to step on toes, but, you can't accurately fill an R134a system using only gauges. A system built in 05 will have R134a and not R12 in it.

Sounds like I am wrong according to RinkersRanch. Apology extended for inaccurate suggestion, but a good A/C tech would have told you was wrong too.

H. Miller · 03-23-2012, 07:26 AM

To answer the original question (how do we get off on such tangents?) a rear compressor (diesel) should require approx. 4 lbs. of R-134....
Final amount tbd per rinkersranch.

Mike Canter · 03-23-2012, 07:52 AM

I agree with H. Miller in that it is going to be right around 4 lbs. The actual amount required is stated in my MH manual and it is 4 lbs.

TXiceman · 03-23-2012, 08:10 AM

Rickersranck,

Any decent A/C tech should be able to properly charge a R134a system with a set of gauges and a thermometer (or thermocouple). I have been in the refrigeration and A/C business for over 40 years and the thermodynamics and heat transfer facts have not changed.

The refrigerants that give you problems charging with a gauge set are the 400 series blends (like R407c, R410a, etc.).

Ken

Bug512 · 03-23-2012, 09:34 AM

Quote:

Originally Posted by TXiceman

Rickersranck,

Any decent A/C tech should be able to properly charge a R134a system with a set of gauges and a thermometer (or thermocouple). I have been in the refrigeration and A/C business for over 40 years and the thermodynamics and heat transfer facts have not changed.

The refrigerants that give you problems charging with a gauge set are the 400 series blends (like R407c, R410a, etc.).

Ken

I was going to say the same thing. You can not measure out refrigerant when you have a chiller or air handling unit that holds several hundred pounds.

I need gages, thermometers and a temperature and pressure chart.

TXiceman · 03-23-2012, 09:45 AM

Bug512...I hear you. I also work on systems holding over 20,000# of refrigerant.

But these are flooded evaporators and you charge by liquid level.

Ken

KIX · 03-23-2012, 07:29 PM

Quote:
Originally Posted by TXiceman
Rickersranck,

Any decent A/C tech should be able to properly charge a R134a system with a set of gauges and a thermometer (or thermocouple). I have been in the refrigeration and A/C business for over 40 years and the thermodynamics and heat transfer facts have not changed.

The refrigerants that give you problems charging with a gauge set are the 400 series blends (like R407c, R410a, etc.).

Ken
I was going to say the same thing. You can not measure out refrigerant when you have a chiller or air handling unit that holds several hundred pounds.

I need gages, thermometers and a temperature and pressure chart.

So...........it seems that I've been redeemed.

__________________

Bug512 · 03-23-2012, 07:46 PM

I understand what RinkersRanch is saying.
In a past life I was a automobile mechanic for 10 years we charged by weight. Line runs are not a issue with automobiles. If the sticker says 2 lbs. 4 oz. that is what it is.
With the machines we had in the late 80's and 90's they would reclaim the old refrigerant, vacuum the system, hold the vacuum and then charge the system. I was fortunate enough to get certified to handle refrigerants when the stricter EPA guidelines came around. I now possess a Universal refrigerant license along with a New Jersey blue seal refrigeration and blue seal operating engineer license.
I can guarantee that a automobile mechanic does not know about superheat or subcooling is nor do they grab a temperature and pressure chart. They know what acceptable gauge reedings look like and what the temperature is coming out of the vents.

TXiceman · 03-23-2012, 09:33 PM

Quote:

Originally Posted by Bug512

I can guarantee that a automobile mechanic does not know about superheat or subcooling is nor do they grab a temperature and pressure chart. They know what acceptable gauge readings look like and what the temperature is coming out of the vents.

And that is the type that I will not let get near my equipment. These are the ones that give the good techs a bad image. They are parts changes and not technicians.

Ken