2nd A/C Question

[Art-n-Marge]

If you drop the molding from the ceiling surrounding the opening where the A/C will be installed you should be able to tell by looking to see what's there. You should be able to see if it can be ducted into existing ducting, see if the 110v wiring is present and if there are control wires going back toward the Main Thermostat. In my unit, only the 110v wires are present therefore I can run wires back to the thermostat or add ducting to connect to the existing ducting, but these would be too much work for me and don't want to incur the cost or hassle so I'd go with a drop in.

Depending on what you find you will be able to tell what you can do.

As for ducting into the existing ducts the units will not fight each other. In fact, what you'll get is more air flow at the vents since the air being pushed by both units needs to come out somewhere and it will use the existing vents which are the points of least resistance. Therefore, you can expect much more air volume being ducted into the rig. The rear unit pushes air toward the front and the front unit pushes air toward the rear and all the vents realize an increase of cool air coming out the ducting as both units push air into the ducting. This would be better distribution since the air is distributed more evenly through the mostly evenly distributed vents.

If you decide to add a discrete unit, then close off the vents from the other A/C in that area since those areas would be getting the air from the new A/C in that area.

Whatever you do, you might want to find a way to close off the openings in your steps that are used for furnace ventilation. Since you are not using the furnace closing the area off might allow more of the cooled air to stay in the rig. Many members have designed covers to fit over these return vents but you must remember to remove this cover when using the furnace.

[PackerFan]

Thanks Art...I have already closed off the air return vents under the stairs with foam board. It has made a big difference in cooling the rig. Learned that trick a while back from other posts here on the MOC.

Scott

[cdaniels]

When u place the order for the unit make sure u tell them you need a ducted unit. And tell them you need the mounting screws there are 4 long bolts. It's a separate cost. Most people seem to replace and use the existing bolts. When we got ours it was missing them and we had to wait for them to send them. Just a FYI. Could be who took the order missed it but thought I would pass that along to u so you won't have the same issue. Sounds like u will have excellent help. Good luck!

[Slufoot733]

We just had a Dometic Penguin 13.5 low profile installed. I think my dealer took me to the cleaners but I had little choice. CW offered it for $795 + $80 installation. I ended up paying $1100 but there are no CW's anywhere near me. We did NOT have it tied into the thermostat for two reasons:
1. that requires a different circuit board for the A/C unit and a different vent cover.
2. If the A/C is tied to the thermostat and it should fail then BOTH A/C units are out of service.

The new unit works great and cools from the bedroom down. We run it during the hot day and it cools the trailer pretty well. Then at night we shut it down and run the one in the living room. So far so good.

[Art-n-Marge]

Forgot to mention in this topic, my 2006 has the second A/C prep, but it only consisted of 110v wire availability (no duct support, or control wires). Even though my thermostat has 2 zone controls, I do not have any control wires for the second A/C prep and therefore if I ever get the second A/C it will be a discrete unit and not get ducted into the existent. I could go through all the extra work, but don't feel the need. Others have gone through the extra work and/or had the extra ducting & wiring. Many things are possible.

[kampk]

Scott, we are also installing the Penguin II low profile on the front of our 2011 3400RL as well. The unit you need for the ceiling is called the "Lower Ceiling Assembly" and when the dealer orders it you can select ducted or non-ducted. Our model has all of the wiring for the thermostat and the power in place, so we are going 'ducted'. We put the Penguin on the roof by laying a carpet on the front cap, utilized my extension ladder setting in the back of the Tow Vehicle and slid it up the ladder to the roof. More bulky than heavy, but I'm guessing somewhere around 80-100 lbs in the box. We removed the existing vent, cleaned up the excess sealant tape and placed it over the hole. Thankfully, since the "Lower Ceiling Assembly" is not supposed to hit our Camping World until this coming Wednesday, it has pretty self sealed itself to the roof because we have had lots of rain here in New England for the last week, and no leaks!! Can't wait to get it all completed!