Air conditioner cooling

[LandKO]

I’ve search for previous posts on my particular problem but have not found what is causing the issue.

We bought our 2018 Freedom Elite 30FE almost 3 years ago. It has a Coleman Mach 3 13000 btu air conditioning unit.

At first the air conditioner cooled the RV to an acceptable level (mid 70’s) unless it was extremely hot. The air coming out of the vents read in the mid 50’s - low 60’s.

This year, it just has not performed as it has in the past.

I’ve cleaned the evaporator and condenser coils, played with repositioning the thermistor probe, did a mod to optimize air flow, and during the day, in shade, the best the AC can do is 80 degrees inside. Outside temps are in the low to mid 90’s. The RV will not get down to our set 78 degrees and shut off until well after dark.
The air temps coming out of the vents only gets down to the low 60’s, unlike the 50’s of past years.

I don’t know what has changed. I called a mobile RV mechanic and he said he could get to me to look at the unit by late August. However he did tell me that if the problem was being caused by low Freon, that the Coleman unit is not designed to add coolant.
Can anyone offer some insight or offer ideas I haven’t incorporated as to what is causing my problems.

[abjbrtd]

Sounds like low freon.
Check local home ac repair, you might find one that can add some freon

Here's a Google search for
"Freon for Coleman mach 3"
Lots of good info

https://www.google.com/search?as_q=&...filetype=&tbs=

Here's a YouTube, looks pretty easy NO soldering there are more videos.

https://m.youtube.com/watch?v=GzowQ9Lgbhg

Good luck and keep us updated

[EA37TS]

Cannot be recharged. Coleman Mach are sealed units.

https://www.airxcel.com/rv/coleman-mach/service-support/faqs

[LandKO]

Originally Posted by abjbrtd

Sounds like low freon.
Check local home ac repair, you might find one that can add some freon

Here's a Google search for
"Freon for Coleman mach 3"

This looks like a possible solution, if the unit is, in fact low on Freon.
It appears that if the Freon is low, the only other option is to replace the AC unit.
When we get home, I’ll explore finding a good AC guy willing to try the saddle valve solution. If it doesn’t work, nothing lost other than the cost of the service call because I’d end up replacing the unit anyway.
Thanks for your suggestion.

[LandKO]

Been unable to find an A/C guy willing to mess with a sealed system like I have on our rooftop air conditioner. So, I’m shopping around for a replacement unit at a reasonable price.
Meanwhile, I’ve added a second A/C unit in the bedroom. Will post what I have done in the hear future on the modifications link.

[DavidEM]

Originally Posted by LandKO

Been unable to find an A/C guy willing to mess with a sealed system like I have on our rooftop air conditioner. So, I’m shopping around for a replacement unit at a reasonable price.
Meanwhile, I’ve added a second A/C unit in the bedroom. Will post what I have done in the hear future on the modifications link.

Replacing the A/C is probably your best solution. Packaged A/C units like window units and RV rooftop units are not meant to be recharged with freon. Any leak means a crack in the tubing that may be impossible to find. Better to replace it. I think low freon happens very rarely in packaged units.

David

[TGunter]

This week while in Galveston, I had to have a mobile RV service look at the Coleman 13.5BTU unit on my 2019 Freedom Elite 26HE. It was not cooling as well as it used to.

Having checked everything, the tech said that some of the coolant had leaked. He said they didn't use freon but some other gas whose name I don't remember (could it have been puron?) The only solution since it's a sealed unit is a replacement.

Total cost for the replacement was just over $1300 which was money well spent when it's 95 outside and 85 inside! I was also pleased that they had a new unit available in these days of parts shortages.

[ColoradoCal@gmail.com]

Newbie owner of 2022 Thor Compass. If there are 2 kids in car seats in the dinette, for air conditioning, what is best? Can you run the generator to power the rooftop air conditioner, while driving? Thanks!:

[EA37TS]

Originally Posted by ColoradoCal@gmail.com

Newbie owner of 2022 Thor Compass. If there are 2 kids in car seats in the dinette, for air conditioning, what is best? Can you run the generator to power the rooftop air conditioner, while driving? Thanks!:

We use the generator for AC while traveling all the time. Just keep track of the generator service schedule.

[LandKO]

Originally Posted by TGunter

This week while in Galveston, I had to have a mobile RV service look at the Coleman 13.5BTU unit on my 2019 Freedom Elite 26HE. It was not cooling as well as it used to.

Having checked everything, the tech said that some of the coolant had leaked. He said they didn't use freon but some other gas whose name I don't remember (could it have been puron?) The only solution since it's a sealed unit is a replacement.

Total cost for the replacement was just over $1300 which was money well spent when it's 95 outside and 85 inside! I was also pleased that they had a new unit available in these days of parts shortages.

We ended up replacing our rooftop unit as well. This past Saturday, my son and I removed the existing unit and replaced it with a new Coleman 13,500 unit that I had found online from United RV in Texas. I reused inside plenum, control box and tempprobe from the old unit so for less than $800 we had it up and running in less than two hours.

Low Freon was definitely the cause of the original unit to fail because the new one is cooling a 100% better.

[Chance]

Originally Posted by LandKO

....cut....

We bought our 2018 Freedom Elite 30FE almost 3 years ago. It has a Coleman Mach 3 13000 btu air conditioning unit.

At first the air conditioner cooled the RV to an acceptable level (mid 70’s) unless it was extremely hot. The air coming out of the vents read in the mid 50’s - low 60’s.

.....cut.....

Glad replacement worked out for you, but based on the information you supplied, it doesn’t sound to me that the air conditioner was not performing as expected, or very close to that.

Coleman specs state that 15 to 20 degrees F of cooling between inlet and outlet is normal. If your motorhome is cooling down to 80 F and air out of your vents is in low 60s, that’s within expected 15~20 F performance. Additionally, if you modified the vents to increase air flow, that means air temperature won’t drop as much across the evaporator.

I hope your new A/C will make you comfortable, but in hot weather I don’t expect any 13,500 BTU/hr air conditioner will make a 30-foot motorhome cool. My 24-foot Class C wouldn’t cool under 80 F when hot with a 13,500 A/C, and I doubt your motorhome is insulated all that much better.

[Bob Denman]

I wonder how much better the 15K units work?

[LandKO]

Originally Posted by Chance

Glad replacement worked out for you, but based on the information you supplied, it doesn’t sound to me that the air conditioner was not performing as expected, or very close to that.

Coleman specs state that 15 to 20 degrees F of cooling between inlet and outlet is normal. If your motorhome is cooling down to 80 F and air out of your vents is in low 60s, that’s within expected 15~20 F performance. Additionally, if you modified the vents to increase air flow, that means air temperature won’t drop as much across the evaporator.

I hope your new A/C will make you comfortable, but in hot weather I don’t expect any 13,500 BTU/hr air conditioner will make a 30-foot motorhome cool. My 24-foot Class C wouldn’t cool under 80 F when hot with a 13,500 A/C, and I doubt your motorhome is insulated all that much better.

Perhaps I was not clear on my original post.
The 80 degree temperature mentioned was at the thermostat mounted on the hallway wall.
The actual differential between intake air at the plenum and the closest vent was only 5 - 8 degrees. Temperature at the vent was in the low 60’s in the morning while the measurement at the intake was about 68 degrees. Later in the day, closest vent temperature was upper 60’s to low 70’s while intake air was mid 70’s. The distance between the closest vent and the intake is less than three feet.
As I measured temperatures at vents further away from the intake, they went higher and the differential less. This is with the compressor running constantly.
With the heat load coming in from the ceiling and walls, the unit was not able to maintain anything lower than 80 degrees at the thermostat.
The new unit has a temperature differential of at least 20 degrees. My hope is that the new unit, plus the 15,000 btu unit I added in the bedroom will maintain a more comfortable overall temperature even in the hottest weather.

[bevedfelker]

In reply to Bob Denman's post -- when we bought our 2015 Vegas 24.1, it had the 15K AC instead of the 13.5. We bought the RV in Tampa and we were living in Tampa from 2014-2018. We used the RV a lot in the strong FL heat.

I often read complaints on the forum about marginal cooling from 13.5 units. My wife could turn our RV into a meat locker with the 15.0 unit -- regardless of what the outside temperature was. We never had a lack of cooling with the 15.0 unit, and a lot of our camping was in triple digit outside temps.