Need info: Dometic RV Roof Top A/C


Information, ideas, experiences and help with camping, pulling a trailer and roughing it on your Goldwing
  • Sponsored Links
Post Reply
User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Wed May 30, 2018 8:29 pm



Hey!! You guys that work on, or know about, RV Roof Top a/c units. how much Temperature Differential should there be? My unit is only doing 10°F differential between Inlet and Outlet temps.

mine is a Dometic 59530.(X)3(X)(X) and the compressor pulls 8.0 amps at full run, 120 VAC of course.
I just installed a new fan blade for the outside heat exchanger, old one was warped.





~John

User avatar
WingAdmin
Site Admin
Posts: 19630
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: Need info: Dometic RV Roof Top A/C

Post by WingAdmin » Wed May 30, 2018 8:33 pm

It should definitely be doing more than 10 degrees, you will get more than that from a peltier junction cooler!

And I hate to say it...but if it is low on coolant, get ready to break out the wallet, because it uses ancient, now-banned R-22 refrigerant, which is just about impossible to find, and astronomically expensive if you can find it.

User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Wed May 30, 2018 8:34 pm

yeah, I was hoping for at least 20°F and the HVAC in my house is close to 39°F


i used to have a 30lb bottle of R-22 but someone stole it a couple decades back.

when that new rule came out, I stopped at every auto supply house between Albuquerque and Flagstaff, AZ and bought every can of R-22 they had.... lasted me a long time.... had a 1974 Suburban back then, and it leaked enough to need a refill every six months.
~John

User avatar
WingAdmin
Site Admin
Posts: 19630
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: Need info: Dometic RV Roof Top A/C

Post by WingAdmin » Wed May 30, 2018 9:46 pm

That 30 lb tank would be worth $500 today!

I can remember when you could buy pellet guns that were powered from R-22 canisters, because the stuff was so cheap. If we only knew then...

DaveO430
Posts: 1021
Joined: Fri Jan 02, 2015 7:28 pm
Location: Amity. Ar
Motorcycle: 2010 GL1800
2004 Suzuki DR200

Re: Need info: Dometic RV Roof Top A/C

Post by DaveO430 » Thu May 31, 2018 5:59 am

AZgl1800 wrote:
Wed May 30, 2018 8:34 pm
yeah, I was hoping for at least 20°F and the HVAC in my house is close to 39°F


i used to have a 30lb bottle of R-22 but someone stole it a couple decades back.

when that new rule came out, I stopped at every auto supply house between Albuquerque and Flagstaff, AZ and bought every can of R-22 they had.... lasted me a long time.... had a 1974 Suburban back then, and it leaked enough to need a refill every six months.
That 74 suburban used R12, not R22.

User avatar
themainviking
Posts: 3253
Joined: Wed Sep 29, 2010 6:59 pm
Location: North Bay, Ontario, Canada
Motorcycle: 2009 GL1800 AD
1987 Harley Softail Custom
1974 Harley FLH (sold)
1965 Harley FLHE (sold)
1957 Harley Chopper (sold)

Re: Need info: Dometic RV Roof Top A/C

Post by themainviking » Thu May 31, 2018 6:10 am

RV units are similar to home Air Conditioners, only smaller and less efficient. The label you provided does not list the BTU Capacity, but I would not be surprised if a Dometic unit at 8 amps could only pull the air down 10 degrees. The 13,500 units on Airstreams which run at 15 amps can only pull it down about 15 degrees. In Arizona, due to the lack of humidity in the ambient air, you will not get the air drying effect (lack of humidity also feels cooler).

Is your home unit a Swamp Cooler? When I lived in New Mexico, that is all anyone had. They will bring the temps inside down to 62 degrees, which is the evaporative point of water. If the house is hot, it will take several days.
It ain't about the destination - it's all about the journey

Image

User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Thu May 31, 2018 10:43 am

When we lived in Borger/Stinnett Texas area, our home was cooled by a huge 3500 cfm swamp cooler, very familiar with those.

then in Mesa, AridZona I bought a double stage swamp cooler for the back patio, set it on one side and 4,000 cfm would cool the entire length of an 80 ft wide patio.... those were the days alright.

here in Oologah, Oklahoma north of tulsa, it is running over 50% humidity most of the time....
that little roof top unit on the RV had to run for 3 or 4 hours before it really dropped the interior temp it seemed like...

actually, I was just in a hurry because it started out at 97°F interior temp and my daughter went out 3 hours later and reset the 'stat to 74°F, she said it was 'too cold'.....

okay, sounds like it is doing all it can do with just an 8 amp compressor on it.

I have a 11,500 BTU window unit in my garage that pulls 3.75 amps start, and runs at 1.5 amps
it does one hell of a good job, pulls the garage down to 68°F on a 100°F day

i really enjoy that one, lets me work on stuff any time I want..... my body can't handle humidity and high temps anymore.

Oh, the Suburban? yeah, it was R-12 freon..... I was still thinking HVAC mode :shock: :shock:

My 2001 Suburban is R-134 and I just had the thrill of replacing all of the good stuff on it last month, cost me $1350.
the compressor cratered and spewed junk everywhere.
the rear a/c line was leaking, oozing right thru the line itself..... and all of the O-rings were seeping....
the guy who fixed it is good, but I had to pay for a "Quality Job" to get it done Right.
~John

User avatar
Mountain rider
Posts: 101
Joined: Sun May 14, 2017 9:03 pm
Location: Rigby, Idaho
Motorcycle: 1986 Aspencade SEI 1200
2003 Goldwing 1800

Re: Need info: Dometic RV Roof Top A/C

Post by Mountain rider » Sun Jul 01, 2018 8:36 pm

Is this running in the toy hauler? If so, are you running it with the quick cool vent open all the time? Even if there's little humidity, the condenser can freeze up reducing your cooling air to nothing. Use the quick cool vent to get things moving toward cool, then shut that vent and let the cool air move through the duct work. It takes longer to cool down, but is more effective. I'll check my Dometic book tomorrow and see if it covers the model you have. I may be able to get some specs. I can tell you that at our dealership, we don't recharge them, it's easier and cheaper overall to replace them. Most of the newer units we see these days are 15,000 BTU and draw about 15amps to start up.

User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Mon Jul 02, 2018 12:51 am

Mountain rider wrote:
Sun Jul 01, 2018 8:36 pm
Is this running in the toy hauler? If so, are you running it with the quick cool vent open all the time? Even if there's little humidity, the condenser can freeze up reducing your cooling air to nothing. Use the quick cool vent to get things moving toward cool, then shut that vent and let the cool air move through the duct work. It takes longer to cool down, but is more effective. I'll check my Dometic book tomorrow and see if it covers the model you have. I may be able to get some specs. I can tell you that at our dealership, we don't recharge them, it's easier and cheaper overall to replace them. Most of the newer units we see these days are 15,000 BTU and draw about 15amps to start up.
Yes, this unit is the factory installed a/c for the Weekend Warrior Toy Hauler. We keep the garage door closed. so the heat in there does not come into the coach.

I'm not sure what you are calling the "quick cool vent"? is that the vent that blows air straight down into the coach? if so, I have been leaving that open all the time..... is that bad?

we just leave it on High Fan locked on so the fan does not cycle. Easier for us to sleep that way.
Since the new plastic fan was installed, the noise level is very low.

2 weeks ago returning from Colorado in 93-97* temps, it was giving us 21 degree differential after the coach cooled down... the stat is set at 74 and it easily pulled the coach down to that in about 3 hours....

there was one day that we sat in Lamar, CO in 107* heat when we pulled into the RV park.... the dogs and us literally melted when we got out of the truck..... the truck's a/c is working like a freezer, the repair on that unit was superb, worth every penny.

anyway, the coach interior was about 93* which I thought was pretty darn cool considering the OAT of 107.
the Dometic dutifully cooled it down to 74 by bedtime... don't recall the time involved.... we got there at 5 PM.

if I can do anything else to help it out, it would be nice. I looked at replacing it with a 15k BTU model and the $700+ price killed that idea. as for having it worked on by a a/c tech, ain't going to happen. if it quits, will get a new one.

I would sure like to find a vendor that will get closer to wholesale on that thing.
AdventureRV.net so far has been the cheapest place I have found for repair parts.

.
~John

User avatar
Mountain rider
Posts: 101
Joined: Sun May 14, 2017 9:03 pm
Location: Rigby, Idaho
Motorcycle: 1986 Aspencade SEI 1200
2003 Goldwing 1800

Re: Need info: Dometic RV Roof Top A/C

Post by Mountain rider » Mon Jul 02, 2018 8:25 am

The vent that comes directly from the unit is the one I was refering to as the quick cool vent. It's normally just to knock the heat down a bit so you can tolerate being inside, then it should be closed so the cool air can pass through the ductwork and spread it throughout the trailer. I'll check my book when I get to work.

User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Mon Jul 02, 2018 8:36 am

Mountain rider wrote:
Mon Jul 02, 2018 8:25 am
The vent that comes directly from the unit is the one I was refering to as the quick cool vent. It's normally just to knock the heat down a bit so you can tolerate being inside, then it should be closed so the cool air can pass through the ductwork and spread it throughout the trailer. I'll check my book when I get to work.
Okay, we are on the same page now.

We were moving the air around in the coach with a box fan setting on the lower drawer under the kitchen sink leaning back against the drawers above it. It angled upwards to the ceiling about 10 feet back of the a/c unit. It moves a lot of air, and kept air moving around inside the coach pretty good.

My daughter says next time, we are closing that vent and turning off that noisy box fan. Box fans are so loud you can't hear a TV set, and we take DVD movies with us to watch after dark.
~John

User avatar
Mountain rider
Posts: 101
Joined: Sun May 14, 2017 9:03 pm
Location: Rigby, Idaho
Motorcycle: 1986 Aspencade SEI 1200
2003 Goldwing 1800

Re: Need info: Dometic RV Roof Top A/C

Post by Mountain rider » Mon Jul 02, 2018 11:33 am

That should help. The book says the AC should reduce the temp by 30% of ambient. So at 100* it should cool to approximately 70*. That will vary dependent on the unit, insulation, and ambient temperature. The hotter it is, the harder the unit will have to work. Good luck

User avatar
AZgl1800
Posts: 1324
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Need info: Dometic RV Roof Top A/C

Post by AZgl1800 » Mon Jul 02, 2018 2:35 pm

it is cooling to 74* on 100* days, so it must be okay.

the 1st week out with it, we set the stat at 66 and woke up about mid-morning freezing our buns off.

the blankets we had were more like sheets :lol: :lol:

my daughter got up and rolled that stat back to 74 and said "that is where it stays" :D :D


~John

Post Reply