Atwood Air Conditioner/Heat Pump

KatanaPilot · 03-09-2016, 05:38 PM

I just completed the installation of a 15K BTU Atwood Air Command Heat Pump on my 2015 Forester MBS with a QD3200 Diesel generator.

I removed the old Dometic 13.5K Brisk Air II A/C only unit - it was very noisy, there was little difference between high and low fan speeds and the diesel generator did not like the 13 or so amps that this unit draws.

The Atwood is wonderfully quiet - we can sit at the dinette right under the diffuser, wide open and on high - and still have a non-shouting conversation. (We would frequently turn off the Dometic during meal time because it was so loud). Additionally, I ran the A/C on high, the battery charger/converter was on high and then I ran the microwave. Could not do that before with the Dometic. The Atwood pulls about 10 amps for cooling, I think about 12 for heating.

The mechanical part of the installation is easy. For me the most difficult part was figuring out the different wiring configuration. The Atwood has a proprietary communicating thermostat, but once I understood which wires went where, that was easy too. The Dometic tsat only uses three wires, but there is a 6 conductor wire run from the roof unit to the tsat in the back.

I am thrilled with this modification and highly recommend it to anyone especially if their Dometic unit fails. The Atwood is only a little more expensive and now I have a heat pump unit where before it was A/C only.

If anyone wants a one year new Dometic unit complete for about half the cost of new, PM me. I am in the Atlanta area but will drive a little way to meet you.

nusslejj · 03-10-2016, 08:29 AM

KatanaPilot - were you able to use the existing FR wiring from the Dometic that you removed ? If so, would you be able to post a pic of how it is wired ? Several of us may go the route you went, as that Dometic is loud enough to wake the dead, and you are right - the difference between high-fan and low-fan is negligible.

Also did you look at other Dometic models - like a Penguin gen 2 ? I wonder if they have a quieter/more energy efficient model that would fit the same ceiling shroud and wiring.

Thanks !

KatanaPilot · 03-10-2016, 10:17 AM

Sent you a PM.

TURBS · 03-10-2016, 10:39 AM

Look at ppl motorhomes, they have conversation kits

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

TURBS · 03-10-2016, 10:41 AM

Quote:

Originally Posted by KatanaPilot

I just completed the installation of a 15K BTU Atwood Air Command Heat Pump on my 2015 Forester MBS with a QD3200 Diesel generator.

I removed the old Dometic 13.5K Brisk Air II A/C only unit - it was very noisy, there was little difference between high and low fan speeds and the diesel generator did not like the 13 or so amps that this unit draws.

The Atwood is wonderfully quiet - we can sit at the dinette right under the diffuser, wide open and on high - and still have a non-shouting conversation. (We would frequently turn off the Dometic during meal time because it was so loud). Additionally, I ran the A/C on high, the battery charger/converter was on high and then I ran the microwave. Could not do that before with the Dometic. The Atwood pulls about 10 amps for cooling, I think about 12 for heating.

The mechanical part of the installation is easy. For me the most difficult part was figuring out the different wiring configuration. The Atwood has a proprietary communicating thermostat, but once I understood which wires went where, that was easy too. The Dometic tsat only uses three wires, but there is a 6 conductor wire run from the roof unit to the tsat in the back.

I am thrilled with this modification and highly recommend it to anyone especially if their Dometic unit fails. The Atwood is only a little more expensive and now I have a heat pump unit where before it was A/C only.

If anyone wants a one year new Dometic unit complete for about half the cost of new, PM me. I am in the Atlanta area but will drive a little way to meet you.

Wish you were closer!

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

KatanaPilot · 03-10-2016, 01:08 PM

Quote:

Originally Posted by TURBS

Look at ppl motorhomes, they have conversation kits

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

That is where I bought the Atwood A/C. The first one shipped from their distributor via UPS - box was wet, and pretty much destroyed. A/C was upside down and cover was damaged. Called them, sent pictures and they immediately took care of it - sent UPS call tag, shipped another via motor freight and refunded some of my freight charge for the trouble.

Good folks, would buy components from them again.

Will ship the Dometic to you if you want to pay the freight - but then it probably won't be worth it.

TURBS · 03-10-2016, 01:14 PM

Quote:

Originally Posted by KatanaPilot

That is where I bought the Atwood A/C. The first one shipped from their distributor via UPS - box was wet, and pretty much destroyed. A/C was upside down and cover was damaged. Called them, sent pictures and they immediately took care of it - sent UPS call tag, shipped another via motor freight and refunded some of my freight charge for the trouble.

Good folks, would buy components from them again.

Will ship the Dometic to you if you want to pay the freight - but then it probably won't be worth it.

Pm sent.

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

**RedLdr1** · 03-10-2016, 01:24 PM

What model number Atwood did you use? Did the ducted ceiling kit fit without modifications?

Thanks,

TURBS · 03-10-2016, 01:40 PM

Quote:

Originally Posted by RedLdr1

What model number Atwood did you use? Did the ducting ceiling kit fit without modifications?

Thanks,

There is no "ducting"

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

**RedLdr1** · 03-10-2016, 01:47 PM

Quote:

Originally Posted by TURBS

There is no "ducting"

2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

There are no "conversation kits" either...

Darn auto correct strikes again...

I corrected it to a "ducted ceiling kit" in my post.... Thanks!

KatanaPilot · 03-10-2016, 03:00 PM

Quote:

Originally Posted by RedLdr1

What model number Atwood did you use? Did the ducted ceiling kit fit without modifications?

Thanks,

Atwood 15033, 15K heat pump, 15022 ceiling assembly and adapter 15089. The adapter allows you to easily connect the thermostat wires to the molex connector at both the roof unit and the thermostat. The unit comes with a long data cable, but you don't have to run it (unless you like fishing wires through a motorhome) - I used the existing thermostat 6 wire conductor along with the 15089 adapter.

I had to modify (cut slightly) the plastic T brace that goes in the seams in the ceiling since the Atwood ceiling assembly is larger than the Dometic.

There was no cutting at all to the roof opening as it is standard. The wiring was the most difficult part only because I wasn't exactly sure which wires ran from the roof unit to the furnace. Once I figured that out it was pretty simple.

**Joshua Cavitt** · 03-12-2016, 01:42 PM

Have you gotten to use it while running other appliances in the coach?

KatanaPilot · 03-12-2016, 02:07 PM

Quote:

Originally Posted by Joshua Cavitt

Have you gotten to use it while running other appliances in the coach?

Mr. Cavitt,

In a word, yes. Now for the details -

Shortly after completing the install, I started the generator, let it warm up for 5 minutes and then turned on the A/C on high. The converter (PD9200) was in boost mode as the batteries were a bit low and then I ran the microwave. The generator did not have any problems.

I let it run for quite a while, tried all three fan speeds and then let the engineer spouse come evaluate the install. She was thrilled at the noise level (or should I say lack of noise). We were able to hold a conversation at the dinette directly underneath the ceiling diffuser assembly with the diffuser wide open. It was quieter yet with the diffuser vents closed and even quieter with the fan on low.

Once on shore power, I checked the amperage draw on the Progressive Industries EMS remote display - 10 amps A/C on high with the converter in normal mode, 12 amps when the converter was in boost mode. I had checked the old Dometic under the same conditions - 3 amps more.

Keep in mind the Atwood I installed is the 15K heat pump unit, versus the 13.5K cool only Dometic that was required with the QD3200 diesel generator.

My recommendation would be to take a sound measurement in a unit with the Dometic A/C and compare it to the Isata 3. Mr. Clemens indicated Dynamax is using the Atwood. Clearly, the Atwood performs better (higher SEER), is much quieter and has a lower current draw than the Dometic. Additionally, given the cost of the diesel generator upgrade, if you ever decide to offer it again, increase the price another $150 and include the Atwood as part of the package.

Hope this information is useful to you.

**RedLdr1** · 03-12-2016, 03:00 PM

Thanks for the info and the review.

In good ol' muggy Georgia this looks like a very good upgrade. And cutting the A/C noise levels would be a plus as well....

KatanaPilot · 03-13-2016, 10:28 AM

Quote:

Originally Posted by RedLdr1

Thanks for the info and the review.

In good ol' muggy Georgia this looks like a very good upgrade. And cutting the A/C noise levels would be a plus as well....

I hope so, it was not an inexpensive modification. But it should contribute greatly to our comfort and enjoyment.

Given all the issues with the Dometic (noise, high current draw,reliability, etc.), maybe FR will take note and evaluate the Atwood a/c on the Solera and Forester MBS. The Dynamax Isata 3 Sprinter based MH already has it.

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