Dometic roof top ac

[mike_brez]

Can anyone lead me to any info on how much refrigerant a 1998 Domenic 13.5 btu roof top ac is suppose to have?

[dougrainer]

atsrmf wrote:
Sorry, I'm not missing anyone's point. I have worked with A/C units since the 80s. Doug is simply trying to impress everyone while putting me down. No problem, I understand efficiency and how that affects air temp output. Argue all you want, I'm not really listening. The proof is in the final temperature. This is my final post in this thread, my intent was to advise someone to buy a better unit vs trying to fix junk. Period. How this turns into a lecture on A/C shows how some people are. Goodbye.

I am not putting you down. I am stating FACTS. Facts you may not appreciate, but they are FACTS. That is the problem with forums. People are free to state their OPINION, but not have their own misleading FACTS and get upset when a expert posts the facts, that disputes their opinion. Doug

PS, not only have I "worked" with RV AC units for 38 years, I have probably worked on and REPAIRED(Not replaced) upwards of over 1000 units. HOW many RV Technicians can claim this?:B

[atsrmf]

Sorry, I'm not missing anyone's point. I have worked with A/C units since the 80s. Doug is simply trying to impress everyone while putting me down. No problem, I understand efficiency and how that affects air temp output. Argue all you want, I'm not really listening. The proof is in the final temperature. This is my final post in this thread, my intent was to advise someone to buy a better unit vs trying to fix junk. Period. How this turns into a lecture on A/C shows how some people are. Goodbye.

[Hikerdogs]

atsrmf wrote:
I guess my thermometer is wrong. Today it read 83, ambient air was 113, set on LOW. Old unit, 115 ambient resulted in 95 set on HIGH. Both are Coleman TSR 13.5. Both had clean condensing coils.

I think you're missing Doug's point. An RV air conditioner recycles the air in the coach. It does not pull in air from the outside, so the temperature of the air outside the coach has no bearing on the temperature of the air coming out of the air conditioner duct. To get a more accurate differential you need to measure the temperature of the air entering the AC system intake duct and the air coming out of the cooling ducts.

An automobile air conditioner on the other hand does draw air from outside the vehicle unless the selector is set at MAXAIR. In this case there would be a relationship between the temperature of the outside air and the temperature of the air coming out of the cooling duct.

[atsrmf]

I guess my thermometer is wrong. Today it read 83, ambient air was 113, set on LOW. Old unit, 115 ambient resulted in 95 set on HIGH. Both are Coleman TSR 13.5. Both had clean condensing coils.

[dougrainer]

atsrmf wrote:
This new Coleman A/C would cool my RV to 30 degrees below ambient in a short time. The old one (R-22) struggled to make 20 degrees. It went out in the trash. It was 31 years old and used R-22.

https://photos.app.goo.gl/g5jRBkgo3Liquygi9

Freon 22 versus 410. There is NO difference in cooling capacity. The only difference is, the 410 requires HIGHER pressures to do the same job as Freon 22. 13.5 BTU is 13.5 BTU. HOW you get there is no concern. As long as it does what the BTU states. Your other statement is nonsense also. There is no standard or correlation between OUTSIDE(ambient) and what the inside temp will be. ALL the RV AC does is take the INSIDE hot air and cycle it and output COLD air. Has nothing to do with Ambient temp. Ambient temp will affect how cold the INSIDE will get, but you cannot expect the temp difference measurement to be a test of how well the AC cools. Also, since I have been in the business 45 years and still am. 31 year old Freon 22. Well that means it was NOT ducted. Ducted systems (starting in the early 90's, really made RV AC systems better at cooling and yes, those were Freon 22 systems. Back in 2001, I took a customers DSDP with 2- 15k HP's(Freon 22) and at 103 ambient at 5 PM. it was 68 degrees in the Living room and bedroom. Doug

[atsrmf]

This new Coleman A/C would cool my RV to 30 degrees below ambient in a short time. The old one (R-22) struggled to make 20 degrees. It went out in the trash. It was 31 years old and used R-22.

https://photos.app.goo.gl/g5jRBkgo3Liquygi9

[mike_brez]

I have a hard time believing anything made these days is made better.

[atsrmf]

Just buy a new unit, the quality is much higher. I bought my new A/C on Amazon and couldn't be happier. This uses R410a, a MUCH more efficient refrigerant.
Here it is before I insulated the evaporator housing and put the cover on. $674 included the new ceiling controls. RV and Auto Parts sells it, 13.5K BTU.

https://photos.app.goo.gl/WceqHFwadsJuSa847

https://photos.app.goo.gl/qUQT7ABCuPiJwtmG9

[dougrainer]

mike brez wrote:
It looks to be silver soldered,brazed.
Should it be evacuated?
I had my commercial ice machine re charged last year and they dumped whatever was in it and put new in without evacuating.
The tag on ice machine says to use only r502 not shure what's in it now.

1. Should it be evacuated? YES
2. What good will it do you if you do not find and fix the leak? Unless you are positive the Soldered Schrader valve is not leaking, if there is another leak, and it does not take long for 16oz to leak down to the point there is no cooling, you will be wasting time and money. Doug

[phnguyk]

I would, evacuation also tests for leaks, if vacuum holds you might as well add new refrigerant. If it doesn't hold vacuum, would be a waste to add any, there's a leak.

[mike_brez]

It looks to be silver soldered,brazed.
Should it be evacuated?
I had my commercial ice machine re charged last year and they dumped whatever was in it and put new in without evacuating.
The tag on ice machine says to use only r502 not shure what's in it now.

[dougrainer]

mike brez wrote:
Allready has a port on low side

soldered or a clamp on tap? Doug

[mike_brez]

STBRetired wrote:
You can silver solder on charge ports. Getting you hands on 1 pound of R-22 will be the hard part.

Looks like flea bay has some 15oz cans for around $50 also some 35oz cans
I'm going to call my buddy up when he gets back from vacation. He owns a small ac company and I'm shure he has a big 20er

[mike_brez]

Allready has a port on low side