Roof AC Rep - Dometic Duo-Therm > Brisk Air II - Questions

[HammerToe]

I own a 2008 Keystone Cougar Model 291 RLS fifth wheel trailer. It looks like the OEM roof air conditioner - a Domestic Dometic Duo-Therm Model 57915.541 - which came with the trailer has finally ‘packed it in’ and will need to be replaced.

Based on my research to date, it looks like the (probably most compatible) replacement unit would be a Dometic B57915.XX1C0 Brisk II Polar White Air Conditioner (13,500 BTU 410A).

In terms of installation, I’m trying to decide whether or not to undertake it myself OR go through a dealer to have it all done for me. I emailed a local dealer to ask for a quote.

In response, I was quoted:

• “You are probably looking around $1100 plus $300 for labor IF ‘NON-DUCTED’. There is a good possibility if your unit is a DUCTED unit, then you will have to change the ‘control box’ and the wall thermostat, which could cost you another $300 parts plus $150 labor”.

The latter possibility/expense I did not anticipate (even as a possibility).

I kind of figured that given and assuming that the Brisk II unit from Dometic was (as far as I know) the recommended replacement unit, that it would essentially be ‘more or less’ a relatively simple ‘Drop In Replacement’.

So anyway, I figured I would try to find out what would be involved in replacing my air conditioner, IDEALLY FROM SOMEONE WHO MAY HAVE EITHER PERSONALLY DONE IT OR HAD IT DONE, ASSUMING THE SAME STARTING POINT/UNIT BEING REPLACED WITH A BRISK II unit.

As far as I know - assuming we - the dealer and I are on the same wavelength insofar as the term – ‘ducted’ is concerned: well, the way the current unit works in my trailer is that, in addition to intaking and subsequently expelling cold air directly from the unit itself, it does ‘duct’ cold air through (as far as I can recall without checking) three additional ‘swivel outlets’ ‘forward’ in the interior roof of the trailer - two of them further forward in the trailers ‘living room’ and one more in the trailers bedroom.

This might seem like a stupid question but IS THAT what is Universally Understood the term ‘Ducting’ is supposed to mean? Is there some other ‘form’ or ‘type’ of ‘Ducting’ that I am not aware of?
And assuming that – correctly – that my current unit is ‘Ducted’ – I kind of wonder how that might complicate and thus increase the cost of a replacement being installed due to that fact alone ‘that much’.
Or perhaps it doesn’t… Perhaps it might be the other part of the response that makes me wonder…
“There’s a good possibility if your unit is a ducted unit, that you will have to change the control box in the wall thermostat?”.

I suppose (who am I to say?) that that might be true but I was kind of assuming and HOPING that the new unit would simply pretty much ‘drop in and plug-and-play’, that probably all it would be necessary to get it working would be to connected up to AC (the very final thing, perhaps) and, insofar as other low-voltage connections/communications with the thermostat and whatever else there might be involved, that ideally all you might have to do is plug together a couple of connectors.

So anyway, can anybody help clarify this for me? Would be appreciated.

Has anybody out there actually either ‘gol darn gone and dun it’ themselves and so have hands-on experience or, failing that, had a dealer do it who could help clarify things for me?

Thanks.

[1320Fastback]

philh wrote:
Friend of mine kept his TT in his garage... and had to remove the AC unit every time.

Think I'd have the floor lowered.

[Endricken]

Did have to replace the Thermostat for my new Brisk Air 2 as my old 05 Montana had a legacy “fancy “ Dometic Thermostat with a remote and a phone style connector that I think they only made for 2 years…
Replaced Thermostat With Dometic “Single Zone LCD Thermostat “ 3313192 AC/Furnace
Online Wiring diagrams enabled connecting the old wiring in the wall minus the legacy connector.
Extension Ladder with DW pushing the box and I on the roof pulling with a rope worked well enough
The rest was “easy “ I’ve replaced both AC units that way.

[rhagfo]

Hammer Toe, best get a 15,000 btu unit rather than a 13,500 btu unit. A 13,500 btu unit is typically used for a second unit like in a bedroom.

[philh]

Friend of mine kept his TT in his garage... and had to remove the AC unit every time.

[2_many_2]

jdc1 wrote:
I installed mine as well (65 years old), at a total price of under $700. Took a couple of hours. Hardest part is getting it on and off the roof. An extension ladder and helper are required for that. Others will come along and explain the procedure. It's not hard at all.

Me too (64 years old) I have done it twice, the last time it was on an Airstream so I rented a fork lift and used a pallet for a working platform. I had the forklift and a 12' ladder delivered for 24 hours for about $150.

Both times I did it by myself, with just a ladder I leaned it against the awning tube protecting it with a towel, left the AC in the box, wrapped it in a strap and pulled it up with a rope.

With plenty of time to prep before and lots of time for the finishing touches it turned out 100 times better than a dealer installed unit.

[jdc1]

I installed mine as well (65 years old), at a total price of under $700. Took a couple of hours. Hardest part is getting it on and off the roof. An extension ladder and helper are required for that. Others will come along and explain the procedure. It's not hard at all.

[BarneyS]

I replaced my identical air conditioner a few years ago but with a different make. The replacement you are considering should work fine.
We have an Atwood 15,000 "Air Command" ducted unit and have been very pleased with it. Our previous unit, a Dometic "Duo Therm" lasted about 13 years before we replaced it with the present one. The Atwood is much quieter than the Dometic it replaced.
Air conditioners

You are correct that the term "ducted" means the air is circulated through "ducts" in the ceiling. These ducts may just be tunnels formed via foam blocks or they may be actual ducts formed with plastic or metal. In the non-ducted the cold air comes directly out of the unit into the trailer.

The reason for the additional cost for a "ducted" unit is because the thermostat and control box for the air conditioner unit are separate from the unit itself. On "Non ducted" units, those are built in to the ceiling panel on the inside of the trailer and also contain the controls (knobs and numbers). On ducted units, like yours and mine, the thermostat (think knobs and numbers) is mounted on a wall someplace, and the control box is mounted up inside the air conditioner. Those two items are usually included in the AC price but the ceiling panel is sold separately from the air conditioner unit itself and is an additional cost.

There is considerable more work installing a ducted unit vs a non ducted hence the additional cost. Not sure about $300 worth though.
Barney