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Bambi_Bandit · 06-15-2009, 04:57 PM

One of the "findings" I have made in moving into Cosmo full time is the AC...

Here in Austin we have had heat of 100 degrees. I am in partial shade, but am receiving full sun hitting the front curb side of the 27FB.

At the ARTstream's suggestion, I have put the "radiant foil bubble" barrier insulation between the front solar stone guards and the front wrap windows to "black out" the front bedroom which is receiving full sun in the afternoons.

My AC is set for 69, and in the mornings, it can come close to getting to that temperature at about 73. In the afternoons in full sun, my trailer is at 84 degrees, with the Dometic pushing out 55 degree air measured at the register. I have been able to read 46-49 degrees in the mornings or nighttime. I am told this may be "normal", but to check a few capacitors and PCBA on the AC unit itself, which I will do later today when it cools off.

The remainder of all my windows and vents are covered with day night shades fully closed with curtains drawn. Bathroom vents are closed and fantastic vents are also covered with "radiant foil bubble". Skylights are closed as well using the factory shades. I have all the shades closed all the time, so I don't think I am allowing sunlight to "heat the trailer" anytime before the afternoon sun comes.

Full awnings are deployed on road and curb side, as well as rear, with the front solar guards "blacked out".

Bathroom door is also closed to minimize the area the AC needs to cool

I have the 15K BTU unit. I have seen others post stating that they could "hang meat" with their 15K units in full sun, but I also understand that smaller units and the "mouse fur" and "vinyl ceilings" may also be contributing to insulative qualities.

Does anyone have any thoughts as this being "normal" or not?

I have used my trailer in the texas summers before, but never remember being hot and hiding in the dark trailer with doors and vents closed up as much as this before...

Prim and I and the pups are seriously thinking of putting a second AC unit in with 50A wiring if this is considered normal...

Thanks for any help...

Hot and Houseless in Texas.....

bob34787 · 06-15-2009, 05:22 PM

we have a 28' safari se with the 15,000 btu unit and last week it was 93 in florida and the camper stayed at 71-72 in full sun with no awnings. So I would think something is not right with your unit

Mike Leary · 06-15-2009, 05:53 PM

We have fresh Dometics in Bess, after replacing the Colemans. We bailed out of Arizona because the dweeb Dometics could not keep up with the heat where the Colemans never gave us the sweats.

overlander63 · 06-15-2009, 05:57 PM

This is probably comparing apples to oranges, but it never gets over 82 in our 31 foot trailer--with a 12,000btu a/c.
It sounds like you are doing everything possible to keep the temps within reason. I wonder if there may be a problem with the gaskets on the a/c unit itself, either between the roof and trailer, the duct between the upper and lower unit, or maybe between the pieces of the evaporator.

TxToaster · 06-15-2009, 05:58 PM

We stayed at Caprock Canyon State Park a couple of weeks ago. It was 98. Inside was 84 at the heat of the day and fortunately it didn't get any hotter outside. We are look at installing another AC over the area where the rear vent is. Then we should be able to hang long horns :-)

**jcanavera** · 06-15-2009, 06:17 PM

We had issues with a 13.5K Penguin unit being able to successfully cool a brand new 27' '01 Safari in full sun 100 degree temps. At about 103 outside the best we could do inside was about 86-88 degrees. Sitting next to me was my old white 30' SOB with a 13.5 Duo-Therm Brisk Air AC, staying nice and cool. Nobody could diagnose a problem and the folks at my local dealership could find no problems. I remember contacting Duo-Therm and they noted as long as I was getting 20-25 degrees drop in temperature from air intake to discharge, the unit was operating properly.

I pressed the matter and made an appointment up in Jackson Center to check the unit out. They had noted that they had seen on some units, some improper baffling between the AC unit and the refrigerator compartment. In those cases the AC was getting return air from the refrigerator compartment which would cause poor performance.

Upon inspection they could find no such problem, but they did note that they needed to realign the trailer door since they found it leaking air at the bottom. Since it was a Safari we had no street side awning. We added a full length awning on that side and deployed it in hot conditions. I really don't know if it was the door or the awning but I never ran into that problem again. I also never went out in temps that hot without finding a shady spot.

I opted for the 15K AC unit when we ordered the 30' Slide Out. We have not been disappointed with the performance, but in all honesty haven't been out in 100 degree weather either. I learned a big lesson regarding the fact that shiny aluminum doesn't reflect heat very well.

One other thing is that the thermostat used on the 15K units have three fan speed settings. A lot of us use the auto position which cycles the entire unit on and off. This is great in helping to control humidity but there is an issue you need to be aware of. When using auto, the fan runs at low speed and will only kick into high when you have a difference in set point of the the thermostat and interior temperature of 10+ degrees. In essence you potentially may be running the unit at less than its full capacity and by the time you hit that 10 degree spread, you've lost too much ground to recover.

When we get to hot conditions we set the fan speed to high to not allow this condition to happen.

Jack

slowmover · 06-15-2009, 06:21 PM

Even a Silver Streak has a problem with this level of radiant heat (a trailer with thicker insulation and a complete shell versus the partial A/S shell).

We had a seamstress run up complete new curtains (about 24' as I recall) and installed all with blackout lining, which was a help.

I have heard/read that clear UV film on windows is a help. Our were factory smoke-tinted. Some Silver Streaks came with interior-mount storm windows (all exterior windows are jalousie), and that these are a help.

We also installed insulation and covers for the roof vents.

Afternoon shade is key, obviously, but I was looking to add a second unit.

Saw several 34' Airstreams from central and south Texas with twin roof A/C units in 2007 as we full-timed.

On days where the afternoon humidity was 60% plus, and the air temps above 90F the best our DOMETIC 15m unit could do was 78F at the peak heat point of the day in South Texas on the coast.

We also had an oscillating table fan in the front of the coach.

Allaire Desk Fan - Fans - Utility & Cleaning

overlander63 · 06-15-2009, 06:51 PM

Kevin, if you have any of the oval stack or vista view windows, you can put the radiant foil bubble in them, too. It helps.

Bambi_Bandit · 06-15-2009, 06:59 PM

Went on the roof and took the shroud off.

Capacitors (the start and the mini one from the start) look fine. PCBA also looks OK with no scorch or burns. Had to take the PCBA off the plastic risers, and only got partial view, but front component side looks ok, and the partial view of the back looks good too.

Did notice that Compressor is hot, (normal) but the heat exchanger / fins / coils were only "warm". Like Luke warm.... I would assume this would be hot after running on high for the last 5 hours in 100+ heat...

Others in the RV park seem to think I am low on freon being that I can cool to high 40s out of the vent in cooler ambient temps. We have a "mobile RV repair" guy that comes out to the park and they say the same symptoms I have are remedied with a cut into the freon line, adding a fill valve and filling it up...

I can see this would void the warranty... I am still under warranty for a month or 2 more... but at this point... if I knew it would work for sure, I'd pay anything to keep cool.....

overlander63 · 06-15-2009, 07:15 PM

If you're still under warranty, take it in for the dealer to look at.

**jcanavera** · 06-15-2009, 07:24 PM

I always thought a symptom of low charge was the coils freezing up?? I would second Terri's thoughts. Technically if it's still under Dometic's warranty, any authorized Dometic servicer can deal with this. Is the mobile repair guy an authorized servicer? I had an SOB that was freezing up when new and was down in Florida at the time. The mobile repair guy was authorized and ended up making the repair at no charge.

richinny · 06-15-2009, 08:09 PM

kevin, since you're so good at testing try this.......

see what the discharge temps are at the different fan speeds.

i winter in miami but leave when i start seeing the 90's. i'm in full sun all day long in the 34'. i have a 13.5 btu unit. i find it cools better for me when set on the medium speed. using the fans to periodically discharge the ceiling air helps too.

i'll second the door seal check. if the stabilizers are down it's easy to create a gap in the door if not adjusted properly.

Silvertwinkie · 06-15-2009, 08:33 PM

I vote something is wrong with the unit. I have been in roughly 95 degree heat, direct sun and got down to around 70 degrees inside with my 15k unit.......

rwewed · 06-19-2009, 08:27 PM

I am having the same issue with my 32 excella that has a penguin 13.5 a/c. I think I need to recharge the system.

Please tell me where I can get instruction to recharge my duotherm penguin 13,500 btu unit. Does it have to have R-22 coolant? How do I install the valves to recharge or are there not couplings like in an automobile a/c system?
BUT!
Bottom line though! (I realize I may be commiting blasphemy here) I don't think the Airstream is insulated well, PERIOD! I mean one inch of fiberglass batting has no functional R-factor. I can feel the heat just radiating through the wall! I have seriously considered trying to remove the cheap fiberglass and carefully filling the wall sections with injectable low-expansion foam. Anyone else feel the same? Have any experience in this regard? Airstream could make these things like ice chest if they chose too! I am quite disappointed in this aspect of the Airstream.

SRW · 06-19-2009, 09:21 PM

Kevin:

If the supply fan is not delivering the right volume of air the discharge temp could still be in the range you describe (46 to 49), and the AS would still be warm.

A dirty filter would certainly cause the supply air to be reduced, but I am sure you have already checked that, and besides the evaporator would ice up if the supply volume was severely reduced.

The condenser should generally feel hot to the touch not warm, low refrigerant is certainly a possibility.

I would call Dometic and describe the symptoms. The problem of course will be getting it to a place that has the techs to work on the unit.

SRW

ZoominC6 · 06-20-2009, 04:32 AM

Kevin, One little thing that may help is to insulate the skylights above the shade. I read that you've closed the shade. I purchased some foil backed styrofoam commonly used in the construction industry as exterior sheathing on some homes. I cut pieces to fit and taped two back to back with foil duct tape, placed them in the skylight and pulled the shade over them. This helps in hot weather although I doubt it will be a final solution for you. Good luck and please keep us posted.

TxToaster · 06-20-2009, 06:23 AM

Quote:

Originally Posted by omnistream

I am having the same issue with my 32 excella that has a penguin 13.5 a/c. I think I need to recharge the system.

.....

Omnistream, I had thought the same thing. A friend who is well versed and licensed on ACs came out and read the intake and outflow temps. It was around 10-15 degrees. He removed the bottom AC cover and immediately found that the lower coils were completely clogged. We were also troubleshooting a water pan leak so we ended up removing the AC to clean the coils with the acids that he had. These cleared the gunk out such that you could actually see through the fins of the coils. It took several applications of the cleaning acid. It made a world of difference taking 17+ years of gunk off of the coils. We now have a differential of 30+ degrees. It is very cold air coming out. That said, it still isn't sufficient to cool the trailer down in the heat of a Texas summer day. I can also feel the heat through the top of my trailer.

Davis · 06-23-2009, 08:06 AM

Quote:

Originally Posted by omnistream

I am having the same issue with my 32 excella that has a penguin 13.5 a/c. I think I need to recharge the system.

Please tell me where I can get instruction to recharge my duotherm penguin 13,500 btu unit. Does it have to have R-22 coolant? How do I install the valves to recharge or are there not couplings like in an automobile a/c system?
BUT!
Bottom line though! (I realize I may be commiting blasphemy here) I don't think the Airstream is insulated well, PERIOD! I mean one inch of fiberglass batting has no functional R-factor. I can feel the heat just radiating through the wall! I have seriously considered trying to remove the cheap fiberglass and carefully filling the wall sections with injectable low-expansion foam. Anyone else feel the same? Have any experience in this regard? Airstream could make these things like ice chest if they chose too! I am quite disappointed in this aspect of the Airstream.

Kevin, I may be wrong but I would have to say that the temps you are experiencing are normal compared to the many Airstreams I have owned with Dometic and Coleman units they all suffered when ambient temps were above 95 deg.I also have 52 deg air from the a/c vent with interior trailer temps around 83 deg . A few years ago I looked at a brand new 30ft trailer in 100 deg temps with the a/c on and it was blowing 52 deg air with interior temps around 85 deg and so I figured that was normal for an Airstream.

Omnistream I would have to agree that the Airstreams suffer from insulation. When I contacted the factory they told me that they use a R14 fiberglass insulation but when is packed in between the walls so tightly it looses it efficiency and is actually around a R 7.

I have seen many SOB trailers parked next to me and I can hear their units compressor cycle on and off where mine would run all day in the real hot temps.

I have placed two different fans in front and back of my trailer to help circulate the air and it helps a little.

Silvertherapy · 06-28-2009, 09:08 AM

Kevin,

I also have the 27 ft FB with the 15K unit. Last Week we were up at Inks Lake and during the hottest part of the 100 degree days, our inside got no hotter than 78-80 and we did not have any of the insulating panels up that you have. However, for some immediate relief for a full timer, I would suggest that you did what my neighbor across the street is doing. He lives full time in his 31 ft 5th wheel while he is re-building his house from Ike. He added a portable AC from Sam's and ducted the exhaust out of one of his slide outs,However, that still did not get his temps down! What did work was a $30.00 misting hose strung across the top of his trailer during the day creating an evaporative cooling effect on the top of the trailer. This alone dropped the inside temperature at least 10-15 degrees and he is no longer even trying to use the portable he bought. (and regrets cutting the hole!)
The misting hose is just 3/8" tubing with atomizing nozzles. I got one for my next trip to Lake Livingston next weekend. It is made by Mistymate. (www.mistymate.com)
This does not answer whether or not there is a problem with your AC, but it will give you some immediate relief!

Good luck,

Johnny and Connie Hill

Crusty · 06-28-2009, 11:03 AM

Hey folks - this is 105-108º daily high temps (with high relative humidity) and it it HOT here in central Texas. When a native Texan says it's hot that's probably a quantum step above what most people think is hot.

My 13.5k Penguin is working properly and my 34' Excella is getting up to around 90º during the hottest part of the day (no shade), and down to the high 60's setpoint overnight when the outside air temp may drop to 75º.

I may go buy some Reflectix insulation to block some of the heat entry from windows and the FF's but the heat gain through the walls is incredible. You can put your hand on the interior walls and feel the heat that is being radiated through them, so I think your a/c is doing the best that it can under these circumstances.

Keep lots of ice handy and drink iced tea (the house wine of the south), wear light and skimpy clothes, and stay in the shade.