Dometic air conditioner: ducted vs non-ducted

[steve2777]

I've described my air conditioner not starting in another thread a few days ago, but in reviewing things before the repairman gets here tomorrow, I discovered something I can't explain: my 2018 Siesta 24ST has a ducted a/c system with a Dometic Penguin II 13.5k BTU unit. Even when working, I've never been happy with its cooling capability, and Thor obviously recognized the problem as well, since beginning in 2019 they installed 15k units.

When getting ready for the repairman, I inspected the manufacturer's label on the a/c, which showed Dometic model no. 650015C. However, Dometic's specifications brochure shows this to be a NON-ducted unit, and the 13.5k unit for ducted systems such as I have is model no. 651815C. (There's also a 6519C which is a 15k "high capacity" unit, which is probably what the coach should have had, and the newer models probably do have.)

I don't understand how a unit intended for non-ducted coaches could be installed on a ducted system, and am now wondering whether this could be an error by Thor and a factor in its marginal ability to cool the coach. And if so, where do I go with this information? The coach is 3 months out of warranty, but last year while in warranty I did raise the issue of inadequate cooling with Thor, and even took it to Wakarusa where Thor added two additional vents. So it seems like if the unit itself was part of the problem, I've timely raised the issue.

Can anyone shed light on the ducted vs. non-ducted differences? Thanks.

[Hooligan2]

I think the -description: "non-ducted application ADB required" Means if it is used in a non-ducted installation the inside Air Distribution Box is required. A ducted system uses the thinner "return air package" inside.

[steve2777]

Yes, I've seen the two different types of interior fittings. The Dometic features chart for the Penguin II line shows some models can be used for ducted or non ducted installations, depending on which fitting was used. What prompted my question was that my particular model was listed as ONLY for non ducted use, yet it's installed on a ducted system, raising concern that it's marginal cooling is partially a result of it being the wrong unit for the job.

[steve2777]

Here's what I'm talking about: picture is the Dometic features chart for Penguin II units. Every model can be installed on either ducted or non ducted systems, EXCEPT mine, model 650015C. And yet it's on a ducted system !

[16ACE27]

Originally Posted by steve2777

Here's what I'm talking about: picture is the Dometic features chart for Penguin II units. Every model can be installed on either ducted or non ducted systems, EXCEPT mine, model 650015C. And yet it's on a ducted system !

Do you have ant external thermostat or manual controls at the ADB?

[steve2777]

The a/c is controlled by the Vegatouch Mira / Firefly touchpad that controls numerous other functions as well. Nothing on the overhead.

[16ACE27]

Well then you either have:

1 - A mis-labeled 651815C, or
2 - A modified 650015C

They are the same functional units; the differences being in how they are controlled and the ADB used.

[steve2777]

Thanks, Ace !

[CAW2018SiestaSS]

Originally Posted by steve2777

I've described my air conditioner not starting in another thread a few days ago, but in reviewing things before the repairman gets here tomorrow, I discovered something I can't explain: my 2018 Siesta 24ST has a ducted a/c system with a Dometic Penguin II 13.5k BTU unit. Even when working, I've never been happy with its cooling capability, and Thor obviously recognized the problem as well, since beginning in 2019 they installed 15k units.

When getting ready for the repairman, I inspected the manufacturer's label on the a/c, which showed Dometic model no. 650015C. However, Dometic's specifications brochure shows this to be a NON-ducted unit, and the 13.5k unit for ducted systems such as I have is model no. 651815C. (There's also a 6519C which is a 15k "high capacity" unit, which is probably what the coach should have had, and the newer models probably do have.)

I don't understand how a unit intended for non-ducted coaches could be installed on a ducted system, and am now wondering whether this could be an error by Thor and a factor in its marginal ability to cool the coach. And if so, where do I go with this information? The coach is 3 months out of warranty, but last year while in warranty I did raise the issue of inadequate cooling with Thor, and even took it to Wakarusa where Thor added two additional vents. So it seems like if the unit itself was part of the problem, I've timely raised the issue.

Can anyone shed light on the ducted vs. non-ducted differences? Thanks.

I have the Thor Siesta 24SS. Essentially NO air comes out of the ducts, even when I close off the main in front of the microwave. I'm wondering if I might have the same problem.

[16ACE27]

Originally Posted by CAW2018SiestaSS

I have the Thor Siesta 24SS. Essentially NO air comes out of the ducts, even when I close off the main in front of the microwave. I'm wondering if I might have the same problem.

https://www.youtube.com/watch?v=i70Yjioj0E8