Adding 2nd AC

Dayle1 · 09-01-2013, 04:26 AM

Thinking about adding 2nd AC although I probably will wait until next spring. Anyway, our Cruiser is prewired and wondering what brand, BTU and style (ducted or non ducted) others have installed? While the duct is certainly available, it is only one branch of the 'H' duct, so I'm not sure a ducted model would provide much cooling to the rest of the fiver. So seems like a non-ducted unit would be better, but probably one that can be wired into the existing thermostat.

Also wondering about the wiring as there are 4 sets of wires. 120V power is in it's own box and there are three other sets tucked around the inside vent cover. I'm guessing one set is 12V DC power, one for the remote temp sensor on the bedroom wall and one set goes to the Dometic CCC thermostat. Can anyone confirm this?

So it seems like the Penguin II, non-ducted unit is maybe the best choice, but what BTUs? Please share your thoughts and experience.

geondebi · 09-01-2013, 07:10 AM

Larry,
When I was thinking of adding the second AC to my PP I had all the same questions. I also thought of low profile and standard (about 6 inches) In regards to the ducting or just down blow I the cost was much cheaper to just vent the second AC to the bedroom. I also thought I would really only use it during the hot day and not so much at night. So it one day CW was having a great sale and I got a 15K at a great price. Now there is always a but my unit the shower and bedroom is one and I find it had to vent the steam from the shower sometimes. If you have the enclosed bathroom it should be no problem.

shoe2728 · 09-01-2013, 12:08 PM

just make sure you can add a second air, my 305sk was set up for 50 amp and had wiring for a second air. Simple installation, take off vent in bedroom set a/c in. Only problem the vent stack for the black tank was right behind where the 2nd a/c was suppose to go and a/c would not fit, course I didn't realize it until I pulled off the vent and tried to put in a/c.So check your measurments

martinstwopopfarm · 09-01-2013, 11:45 PM

I had a Dometic 13,500 brisk air installed when we bought our unit. Ours was prewired for a 2nd a/c in the back end of the rv. It is ducted into the system. There is a noticeable difference in cooling the trailer when both units are running, once I figured out how to set the supply grills for the most efficient air circulation. Running the 2nd unit freezes me out at night. We usually stay comfortable in the 100 degree plus Texas heat. Edited by: martinstwopopfarm

gball · 09-02-2013, 01:24 AM

Larry:

Topper's installed a Coleman Mach !!! 13,500 BTU unit for us. It is not tied into the factory ducts or thermostat and has it's own controls. So far we have been very happy with it. The additional unit really helps cool down the trailer on those hot summer days. The installation added about 6 inches in height so we are now at 13' 6". Have to watch some of the low overpasses.

Dayle1 · 09-03-2013, 03:31 AM

Quote:

Originally Posted by gball

Larry:

Topper's installed a Coleman Mach !!! 13,500 BTU unit for us. It is not tied into the factory ducts or thermostat and has it's own controls. So far we have been very happy with it. The additional unit really helps cool down the trailer on those hot summer days. The installation added about 6 inches in height so we are now at 13' 6". Have to watch some of the low overpasses.

George,

Was your Cruiser pre-wired for the 2nd a/c?

gball · 09-03-2013, 03:39 AM

It was pre-wired. They just didn't tie it into the existing duct system or thermostat.

Dayle1 · 09-03-2013, 03:48 AM

Thru my research, I have found what appears to be a huge issue with how CR designed the air distribution system on my Cruiser. Dometic's documentation recommends an 'H' layout and REQUIRES minimum of 8 registers per A/C, so dual A/Cs should have 16 registers (again per Dometic). My Cruiser only has 5 registers and just 2 legs. The curb side leg runs from the main A/C unit to the back of the Cruiser with just 2 registers and the street side leg runs from the A/C to the front of the Cruiser with the other 3 registers. And lacking the other two legs, there is really no practical place to add registers. Dometic's documentation states "Important: </span>Alternate configurations and methods may be used which still allow the air conditioner/heat pump to operate properly; however, these alternate configurations and methods must be approved by the Dometic Corporation in writing."</span></span> So, I've sent emails to both corporations on this issue.

avvidclif · 09-03-2013, 05:20 AM

You have discovered what I found out when researching a second AC for the new trailer. My previous trailer had 2 ducted AC's and only 4 registers. Which according to the Dometic installation instructions I saw was the absolute minimum for 1 AC. That's why I ran one with the quick cool open partially.

My new trailer has the main AC ducted and the second is not ducted, bedroom only. I still run the main with the quick cool partially open and the bedroom ac cools the bedroom. Both use the same thermostat for control which is nice. I had to insulate the bedroom temp sensor to keep the BR ac from quick cycling as the sensor is mounted on the wall just below an outlet.

**mark5w** · 09-03-2013, 06:57 AM

I check with a few friends that have the 2nd ac. All are single units that do not have a duct-work system. It only blows out the sides or ends of the ac. BTW, these were all factory installs. They also came with a remote if your thermostat was not set up for zones.

Edited by: mark5w

Dayle1 · 09-03-2013, 07:19 AM

Quote:

Originally Posted by avvidclif

My new trailer has the main AC ducted and the second is not ducted, bedroom only. I still run the main with the quick cool partially open and the bedroom ac cools the bedroom. Both use the same thermostat for control which is nice.

Clif,

Thanks, that is the way I have been thinking, non-ducted but same thermostat. However, seems like that limits choices to Dometic models and I don't see an inside grill that doesn't include controls.

avvidclif · 09-03-2013, 07:42 AM

Look at the Penguin II. It has 3 choices for the inside piece, HEPA filter with local duct, non HEPA filter with local duct, or ducted. Outside is the same for all 3. It is controlled by the thermostat and cycles just like the main unit.

PMSPKS · 09-04-2013, 02:05 AM

Dayle,

Our 2010 CF32CK did not come pre-wired for a 2nd AC, but I added a 13.5K BTU unit in the bedroom (non-ducted obviously) with it's own power supply. My original 15K has 5 registers, three in the LR and two in the bedroom and it would not get below 80° on a 100° day, even after checking and fixing the leaking duct work. The 13.5K in the bedroom will freeze you out if you leave it on all the time. Usually we just use it to chill down initially and then use it as a supplement on low. We don'trun it at night. If I had to do it again, I may go down to a 9200 BTU unit. Either way, you will like the results of adding the 2nd AC.

Dayle1 · 09-08-2013, 08:22 AM

Quote:

Originally Posted by avvidclif

My new trailer has the main AC ducted and the second is not ducted, bedroom only. I still run the main with the quick cool partially open and the bedroom ac cools the bedroom. Both use the same thermostat for control which is nice. I had to insulate the bedroom temp sensor to keep the BR ac from quick cycling as the sensor is mounted on the wall just below an outlet.

Clif,

I will have the same issue with the sensor on the bedroom wall. What was your fix? I have been leaning towards a setup like yours, both units on the CCC2 thermostat, but which is really more convenient? Independent controls directly over the bed or a single thermostat?

Dayle1 · 09-08-2013, 08:51 AM

This week we have been camped in 100+ degree weather each day and inside temp each afternoon was hitting 82 degrees. That was with using the Quick Cool and closing both bathroom and bedroom doors during the heat of the day and running a box fan for some level of comfort. At night, there was no problem cooling the entire rig with Quick Cool shut off and the compressor and fan cycling on and off as necessary. That is with just 5 total registers in the rig, but also the benefit of dual pane windows and extra insulation in the refrigerator compartment and bedroom floor.

Today I finally had time to also switch the fan from Auto to Hi in the afternoon heat and the A/C is maintaining 79 degrees and the box fan isn't running. So, now I will run in auto mode from sunset til morning, use Quick Cool with doors closed til lunch break and then switch the fan to Hi.

Regarding my 2nd A/C. My original thought was a Dometic Penguin 13.5K (required to work with the CCC2) with a 9.5 inch height and just under 16 amps. However, maybe the Coleman Polar Cub would be a better choice. At 9.2k BTUs it should still provide sufficient cooling, it is 10.6 inches in height, but at just over 10 amps, it is more likely to allow running both A/Cs on 30 amp service for short periods of time.

avvidclif · 09-08-2013, 10:28 AM

The sensor is just a thermistor on the end of a wire. I took the cover off and cup up a thin coozie to get a small piece of foam insulation. I put it over the thermistor and put the cover back on. It seemed to work a lot better and did fine last weekend. The Penguin II is an upgraded Penguin and can be either a 11k or a 13.5k. I didn't look up the current draw nor am I sure which one I have??? On my list to ask next time at the dealer. All I know is I ran both last weekend on a 30A State Park circuit and the temps were over 100.

By using the one thermostat either can cycle when needed, no fan running all the time.

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