Ducted air- cooler/more efficient OR just quieter?

[rp709]

We have a 2015 Flying Cloud 30. Our previous trailer was a 28' Safari with a 13.5 BTU AC. The ducted system is far quieter---the main reason we bought a new Airstream. We opted for 2 AC units. You don't have to run them both at the same time! We can run the 15 BTU center unit and the noise in the bedroom is very low. Likewise the 13.5 BTU unit in the bedroom is hardly heard at the front lounge area. Either unit distributes air through all the ducts. It is now pleasant to sleep with the AC on, unlike in the Safari with the noise the fan running and compressor cycling on and off. Also, the older AC units are very drafty. The ducted air is evenly distributed throughout the trailer and cools it down faster. I bought a 30 amp cord and use it with a single AC unit just like I did with my Safari when it isn't hot or 50 amp service is not available. We are thrilled with this new setup.

[2012FB]

Just an observation: On our 2012 25FB the aluminum interior roof surface would be hot to the touch and radiating heat when in full sunlight, while our 2015 30 Bunk is much cooler under the same conditions. I believe this is due to the added insulation and distance from the roof surface to the interior on the ducted roofs. The heat transfer on the Aluminum (exterior) to Aluminum (interior) is much higher than interiors with non aluminum interiors. My old 1979 25 was much cooler running a single AC. The new 2015 30 Bunk has Dual AC and the full awning package. I also permanently insulated the center skylight and plan on putting exterior covers on the fans. We are almost always in direct sun light and heat when parked and the difference now is very enjoyable. I love my 50A cord!!

[paiceman]

The air duct system was easily fixed, the new version of the ceiling vents were installed, four in the rear bedroom and two in the bathroom toilet and sink area. Can be directed and or closed which puts more air up front and with the two very rear vents stops air blowing on our heads while sleeping.

[merchantmm]

Just returned from my second outing with my 2015 FC 27 FB Twin. We live in Southern California and have a single Ac unit. We have the standard awning setup on our FC. Temperatures during this trim were 100 degrees in the daytime and the trailer was not comfortable at all during the day. The best we could accomplish was 85 degrees during the peak of the day. We were traveling with a family member who was towing a 2007 trailer of similar size. It was not an Airstream and no where near the quality or feature level. I'm embarrassed to say we spent much of the mid day hours in his trailer. When we were at 85 degrees his thermostat had cycled off and his trailer was at 72 degrees.

I took the trailer to our storage facility this morning (Our Airstream dealer) and asked them to look into it. The first question I was asked was "How old is your friends trailer". Upon learning it is 8 years old he told me the refrigerant used in that vintage was far more efficient and could achieve those Ice Box like temperatures. The best we could expect was 15-20 degree differential from outside.

They have my trailer now and I will report back my findings.

By the way, I'm also having significant issues with sticking windows. I've sprayed silicon lubricant but am still wearing out my credit cards unsticking my windows from outside. Any suggestions?

[jcanavera]

What size ac unit do you have on your FC 27? I had a 27' Safari in 2001 with a 13.5k Penguin. I soon learned that 100 degrees would overwhelm that sized unit. Interesting in your comment since I was camped next to the guy who bought my 30' SOB. It had a 13.5 k Duo-Therm. Comfy in his trailer. Upper 80's in my Safari. I learned a lesson and ordered a street side awning for the Safari. That helped a lot. Upgraded the AC unit on my Classic to 15k. I also make sure to put out all the awnings. Aluminum soaks up the sun. My white SOB reflected it.

FYI I took mine back to the dealer and got the same answer. Stopped by Jackson Center on the way home from vacation and they said the unit was functioning to specs. To me the unit was undersized but in 2001 the 15k unit wasn't available to me. Awning on the street side helped cut the solar gain through the skin.

Jack

[rodsterinfl]

We have read through LOTS of the ducted air threads and the consensus seems to be QUIETER, but I haven't seen a lot of discussion about COOLER?

Just saw this article. It echoes what is state across the RV industry. While Airstream is new to ducted AC, it is not new to other makes/models. RVForum is loaded with posts about basement AC not cooling, ducts blowing hot air, etc.; however, there are some work-arounds.

How to Properly Use The Air Conditioner (AC) in Your Camper | Pete’s RV Quick Tips | Pete’s RV Info Blog

The point is that direct-air cools better into the space quicker. If the trailer is 100 degrees inside, so is the duct. Cool the interior first then switch over to cooling the duct. The question I have is how is the duct hump insulated? The idea is similar to getting into a hot car- turn vents on you as it cools down the interior then as it cools direct them away and lower the fan control. I believe the main benefit would be the even distribution of air in a ducted system.

[jcanavera]

I talked to my dealer and his experience is that while the noise level is lower, when trying to cool down a hot trailer, the ducted system is somewhat slower. Not that it is inhibited, but the fact that the cooler air is being more evenly distributed through out the trailer. For those of us without ducts, you know that the area around the main discharges from the box are noticeably cooler than the ends of the trailer. It's just a matter of the cool air working its way back to the ends.

Jack

[rodsterinfl]

Yes, to some degree the cool air is being divided up into ducts so with one AC it would be slower. I did not understand this point of warm "trailer ends" until I was recently in a dual pano unit. I do not experience that though I have experienced uneven air distribution when my fan blower was on low. I redirected air to the rear by closing the front vent and corrected the difference from/warmer rear situation. One thing too is that several have opted for dual AC units. That would overcome cooling challenges but toward the question, it does not mean that ducted air is more efficient. I believe every AS should have a temp/humidity readout inside. That way, no matter what type of AC you have, you can dial in the optimum comfort.

[jcanavera]

Originally Posted by dznf0g

Outside temp CAN play into the equation, but not if the outside unit is appropriately sized to climate and home size.

Same with A/S.

Problem is unlike our homes where proper sizing takes into account your locale, insulation factor and windows, the air conditioner sizing for Airstreams is a one size fits all situation primarily dictated by the size of the trailer. What is proper sizing for one part of the country can be completely wrong for another. You size too big, you get short run times and a cool clammy trailer. Too small and its too warm. Unfortunately most folks don't take that into account when you buy an Airstream.

Also for those of you who have owned white or light colored trailers, most of us purchasing Airstreams have no idea of the heat absorption that aluminum provides. Yes an Airstream's roof is painted white, which helps. But there is a lot more of that body which is not and that's the rub. I learned on my first trip out at 104 degrees in full sun, how inadequate my air conditioner was and how my Safari with a patio awning only, needed a lot more shade, which I resolved later with a full length street side Zip Dee awning.

Most who buy their trailer off the dealer's lot are pretty much stuck with what the dealer ordered for their inventory. When I knew I was buying a new Classic back in late 2003, I made the decision to have one ordered in order to get the 15K heat pump model which was an option. At that time the Classic would have come with a 13.5K AC unit which would have been a major mistake.

So if you stay in the warmer climes, think carefully about your air conditioning needs and consider a higher BTU unit, or if necessary a second unit. If you are buying a model trailer with a patio awning only that will be used in hot climes, consider a street side awning with or in lieu of the larger air conditioning capacity.

Jack

[J. Morgan]

Yesterday in my 31' 72 Sovereign, stock Armstrong A/C I made a log of temperature as measured at the front of the cabin with the bathroom door shut. (Bathroom sacrificed to sauna)

Thermostat set on 74 degrees.

High interior temp measured at 78 degrees at 3:55 PM, exterior temp was 100 degrees.

At 5:30, inside temp was still 78, outside temp was 102.

By 6:45 the interior was 74, exterior still 102.

Direct sun matters a lot with these aluminum boxes.

[rp709]

I have observed that our 2015 Flying Cloud 30 with ducted AC remains much cooler parked in the sun than our 2005 Safari 28. The new trailers have a raised roof profile to make room for the AC ducting. This air gap provides a significant improvement in ceiling insulation. So this is another feature to be aware of. The ducted AC also cools the trailer better than before because a much better air distribution. It is because of the ducted AC that we decided to buy a 2015 Flying Cloud. We love the 30' floor plan too. The second AC unit really knocks the temperature down fast! Then, a single unit will keep things cool quite well. If we are sleeping, we run the middle unit only and and can barely hear it when it runs. This is a major improvement over the older style AC. When in milder conditions, I only use the 30 amp cord and one AC like before. So, dealing with the 50 amp cord isn't necessary most of the time traveling in the Western states.

[jcanavera]

rp709
rp707, I'm curious as to whether your AC unit is larger than what came with your Safari? I noticed that my local dealer's 30 ft trailers have the 15,000 BTU units. In 2005 your Safari may have had a 13,500 BTU unit. That alone may be part of the betterment in cooling between your 2 trailers.

Jack

[idroba]

Originally Posted by merchantmm

I took the trailer to our storage facility this morning (Our Airstream dealer) and asked them to look into it. The first question I was asked was "How old is your friends trailer". Upon learning it is 8 years old he told me the refrigerant used in that vintage was far more efficient and could achieve those Ice Box like temperatures. The best we could expect was 15-20 degree differential from outside.

I have been reading through this thread and just had to comment on this dealers BS statement.

A 13,500 or a 15,000 btuh RV AC unit, properly operating, produces the rated cooling in btuh, totally independent of what refrigerant is used to do the cooling. One refrigerant is not "far more efficient" than another. If the unit is designed to produce, say, 13,500 btuh of cooling it will do that and btuh ratings don't change dependent on refrigerant.

Dealers statements like that one certainly don't help in understanding the issues involved. Any AC unit with the same rating will operate and remove that amount of heat, assuming it is working to specs.

[jcanavera]

Idroba, you are absolutely correct. That reminds me of what the auto dealers used to spout when the refrigerant changed. Yes the refrigerant may not be as efficient, but the manufacturers overcame that obstacle by redesigning the hardware that the refrigerant runs through. So like you said a 13.5 k unit made 20 years ago should produce the same result as a new unit today. At one time those who had the old style refrigerant asked the question as to whether we could switch to the new. We were told no because of the efficiency difference of the refrigerant. But what they didn't tell us was the redesigned equipment overcame those differences.

Jack

[Wayne&Sam]

I've changed both of my Fantastic fans to MaxAir fans. They have a "ceiling fan" mode - the fans will run with the vent closed. I'm going to see if they help distribute the A/C air.

[EarlM]

Originally Posted by mycloud9

2015 Airstreams have ducted air. The TR has a hump on top to accommodate the ducts. The hump is painted white to reflect sunlight / heat. A step in the right direction. Give AS some credit, had to be some engineering considerations. FYI, the hump will still get beat to pieces by a hail storm. Recently proven.

Hail beats up steel also

[lsbrodsky]

Good luck, but I use a fan pointed to blow from back to front, sitting on the floor just about where the coldest air drops from the overhead unit. I find that it equalizes temperature very well and I doubt that a fan stirring up air on the ceiling would do as well forcing the cold air to the front of the trailer. It is a bit in the way when we are awake and moving around but it is just fine at night.

Larry

[moosetags]

Originally Posted by Wayne&Sam

I've changed both of my Fantastic fans to MaxAir fans. They have a "ceiling fan" mode - the fans will run with the vent closed. I'm going to see if they help distribute the A/C air.

Please let us know on that one.

Brian

[rp709]

The Flying Cloud 30 comes with a 15k AC unit and the bedroom option is 13.5k. It would be a little tricky to compare the single unit performance with the Safari 28' 13.5k unit because the FC 30 is 3 feet longer. But, my guess is the result is nearly the same. So a single 15k unit in a FC 30 will be fairly close to the performance of a 13,5 unit in a Safari 28. Which, in my opinion, isn't very good AC performance. We are headed to Bishop, CA this weekend where forecast temperatures are over 100F. The dual unit setup will be outstanding in this situation, making less noise than the old single unit.

[dames7]

Our 2015, 25ft w/one ac works great. At 95 degrees out side it only took 10 minutes to cool down. I was told that AS is coming out with a replacement cover for the air ducts so you can change the direction on which way the air goes, should be out soon.