A/C Thermostat Settings for 2 Zones

[TankerIP]

I'm having some difficulty if figuring out how to set the thermostats between the front and rear for air conditioning. And how to keep temperatures balanced.

Where are the temperature sensors located? When I ask the thermostat to show the current temperature, the readings between zones can be different by as much as 5 degrees. I can't even tell if there is a problem that needs to reported for warranty work.

Since both A/Cs join into one duct to service the whole trailer, how have you balanced the vents?

Which A/C is bigger. I think I was told that Zone 2 (the front) is the bigger A/C in terms of BTU. Is that true?

If someone has a system they use to keep the temps and A/C balanced I would like to hear it.

[5150mike]

I have a 16 25RB with 2 AC, and for zone 2 I had to pull the sensor out from the wall, next to the refrigerator it's under a little white cap with slots cut in it, it would read 85 but the portable thermometer I have was reading 77, it works much better now, and for zone 1 the thermostat is in the control panel in the bedroom like normal. As for which one 8s bigger that is a good question! On thing I will add a tip I picked up here is if you pull the vents at both ends of the trailer it will cool better it work for me, I am looking for some better vent covers hope this helps Mike

[Mollysdad]

In mine, zone 1 is the living area and a 15k unit. Zone 2 is the bedroom and is the 13.5 k unit.
As you said, since the AC is ducted both ac's go to both areas although you probably get more cool air to the bedroom from zone 2 just because it's a shorter trip.
As far as the thermostat, I set the two slightly apart. The tech suggested this on the walkthrough. So if I set the zone 1 living area at 72, I'll set the bedroom zone 2 at 74. The reason for this is to keep the two units from cycling on and off together.

[uncle_bob]

Hi

At night we set the bedroom thermostat about 5 degrees higher than the living area thermostat. You really don't need two A/C's most nights so only the living area one cycles on and off. Day or night we run a fan to circulate the air in the trailer. If we are not running A/C and it's warm out, we likely will be running two fans plus the one in the roof.

Bob

[Al U. Minium]

Our 30 International RB will generally be warmer due to all the windows in the front lounge-living area.

We had ODM check the function of the AC systems and they checked to specification. They indicated the difference was the windows allowed more heat in to the front.

[hhendrix]

In a newer 25 or 27 FB Airstream with dual air there are actually 3 thermistors. There is one in each A/C and another one on the refer wall behind the TV. The one behind the TV is one many consider a questionable location.
All in all what matters is how comfortable you are inside the trailer. Zone 1 is at the front end (hitch) and Zone 2 is at the rear in a FB. One issue (and there are more) is unless the fan speed in Zone 2 isn't set to automatic, you cannot access the furnace and the heat pump comes on instead.

In my trailer Zone 1 is 13.5K and Zone 2 is 15K. If Zone 1 is on, I can feel a decent flow of cool air coming from the vent over the dining table. It's a little bit of a noise factor too. If I only need one and I'm spending my time in the dining area, I use Zone 1 and vice versa in I'm in bed.

[LilPeanut]

In our 2019 Classic, the front zone thermostat sensor is next to the refrigerator door and behind where it is installed is HOT. A hole from the hot area to the inside of the trailer is how the sensor wire is run and some of the air is affecting the sensor reading. That makes the zone 1 temp show warmer than zone 2. The zone 2 wire runs from the small closet through the wall at the floor of the bed.

I removed the sensors from the wall and let them dangle loose. Now all teams read the same and match a separate room thermometer. Now I leave both thermostats set where we want them with no offset and it seems to work fine. The rear runs less.

[Mike G]

I take a very simplistic approach. The temp reading are ofter vastly different, even though the trailer feels fairly uniform. I just set each thermostat 4-5 degrees below its current reading, and then they run about the same amount of time. If that's not cool enough, I turn both down 1-2 degrees until it is. I don't really care what the temp readings are.

[TankerIP]

After reading 5050MIke's reply I understand some of the problem. The temp sensor for zone 2 (living area) is located directly behind and affected by the temperature of the TV. Our TV is on. Using my IR temp gun the temp on the sensor cover was 82 -- on the thermostat it showed 78. But the wall temp below the TV was 72. This is a 6 to 8 deg error. The TV itself was hot at 84 and affecting all the surrounding area above the TV. Now in Zone 1 (bedroom) where the TV was OFF, the thermostat said the temp in the room was 71, and the wall temperature was measured also at 71. This seemed an accurate reading. So bottom line is that the temperature sensor needs to be moved to somewhere other than directly behind the TV.

Another issue I noticed was when running the zone 1 (bedroom) A/C alone. I could feel cooling air was coming out of the Zone 2 intake vents. It seems to me that the intake vents need to be isolated from the distribution duct so that intake and outflow air is not mixed. I'll have to check in to this closer to verify. Anyone else notice this?

I wonder if Airstream can make modifications and fix this since I am still in warranty?

[5150mike]

Originally Posted by TankerIP

After reading 5050MIke's reply I understand some of the problem. The temp sensor for zone 2 (living area) is located directly behind and affected by the temperature of the TV. Our TV is on. Using my IR temp gun the temp on the sensor cover was 82 -- on the thermostat it showed 78. But the wall temp below the TV was 72. This is a 6 to 8 deg error. The TV itself was hot at 84 and affecting all the surrounding area above the TV. Now in Zone 1 (bedroom) where the TV was OFF, the thermostat said the temp in the room was 71, and the wall temperature was measured also at 71. This seemed an accurate reading. So bottom line is that the temperature sensor needs to be moved to somewhere other than directly behind the TV.

Another issue I noticed was when running the zone 1 (bedroom) A/C alone. I could feel cooling air was coming out of the Zone 2 intake vents. It seems to me that the intake vents need to be isolated from the distribution duct so that intake and outflow air is not mixed. I'll have to check in to this closer to verify. Anyone else notice this?

I wonder if Airstream can make modifications and fix this since I am still in warranty?

Great you found it!!! My heat was not from the Television I did not have it on, mine was from the refrigerator, but I definitely can see where the Television would add to the problem. As for the ductwork mine is doing the same thing, please let us know what you find out, Mike

[uncle_bob]

Hi

In our Classic, there is a temperature sensor by the fridge and another by the rear TV.

Bob

[ASwifey]

Our sensors are reversed. Verified by using my blow dryer and watching the temp go up to 103 on the panel in the opposite zone. We've been struggling to get the temp set right in the bedroom for two years! ��

[AstroBruce]

Airstream is playing tricks on all of you. I can't imagine that this is all accidental. When I got my new Airstream, one of the sensors was buried behind a wall. The dealer told me they would have to remove ceiling and wall panels to fix it. That was their way of getting out of the problem. Who would let them do that? I had them send me a new sensor, and installed it myself. Some day I will take a factory tour just to see the hires.

Bruce

Bruce

[rmkrum]

These guys...?? [emoji12]

[AstroBruce]

Originally Posted by rmkrum

These guys...?? [emoji12]

Attachment 372320

Love it. You made my day. I'm saving that picture. It says it all. Nyuk Nyuk

Bruce

[RivetED]

Originally Posted by rmkrum

These guys...?? [emoji12]

Attachment 372320

I love it too!

Our '19 FC25-RBT has about an 8-10 degree, I guess offset is a good term?, between Zone 1 & 2. The TV can make about 3-4 degree difference, from it's zone 2 setting. Zone 2 in the 25-RBT is the front, hitch end and that's the 15K a/c.

At Jackson Center last summer we added that to our punch list and was told; "that is the way it's designed and there is nothing we can do".

It's on my list of eventual mods, the refer fan is tops right now.

BTW: At night I have to adjust the thermostat to accommodate the reduced heat from the TV. We have learned to live with it but it's not exactly 'fine'!
That's why I love the post from rmkrum, must be the engineering staff

[AstroBruce]

Well, I should give you the rest of the story. I was also having problems getting the right temp settings with both ACs running. One AC was always doing all the work. I finally disconnected the sensor from the system. Now, both ACs work off the sensor in the thermostat control. If I set both ACs to the same temp, they both come on at the same time with a one minute delay between the two, and they both turn off at the same time. No more fussing trying to get them to work together.

Bruce

[pbfec1]

Originally Posted by LilPeanut

In our 2019 Classic, the front zone thermostat sensor is next to the refrigerator door and behind where it is installed is HOT. A hole from the hot area to the inside of the trailer is how the sensor wire is run and some of the air is affecting the sensor reading. That makes the zone 1 temp show warmer than zone 2. The zone 2 wire runs from the small closet through the wall at the floor of the bed.

I removed the sensors from the wall and let them dangle loose. Now all teams read the same and match a separate room thermometer. Now I leave both thermostats set where we want them with no offset and it seems to work fine. The rear runs less.

After a lot of research, I have discovered the issue with the thermostst. as you did. I have a 2019 FC 25RB Twin with similar issue. Mentioned to JC when at factory 2 weeks ago having a window replaced (had a major water leak from a fixed window that had a stress fracture in the frame) and no reference to the thermostat.
My own research has corrected the issue, but not sure how to get the thermostat through the wall to area next to refrigerator to remount. Have you remounted or just leaving hanging?

[MarcThompson]

Just a thought from a newbie... but has anyone tested just pulling the TV out of its alcove while it is on and away from the wall and the T-Stat? If not... I am trying that now and IF it results in anything I will update.

[TankerIP]

Mine will not pull out from wall. The 2019 FC config was to keep it flat on the wall. Only the bedroom TV can be rotated and tilted.