Old air conditioner removed... Steps for new installation

[Lothlorian]

I have the old off and I am about finished with cleaning the area for the new gasket. Do I use Vulcum with the gasket.. Any advice in proper procedure will be welcomed. I am putting on a Coleman airconditioner

Brian

[DougZ]

Brian, I'm going to let someone answer that has done this sucessfully, but I would like to ask if you can post some pictures and hints because I have this project coming up soon.

[azflycaster]

The mounting for the original AC units is often different then the mounting of the new ones. My original Armstrong was attached to the outer skin with a hardware store full of fasteners and sealant. The current AC units attach by clamping the upper and lower assemblies between the outer and inner skins.

In order to install a newer AC unit you must have support (framing) between the outer and inner skins where the unit is clamped. Without the frame the skins will bend and buckle.

[Wsmith]

If it is a designed gasket then you would use nothing but the gasket for the installation. Do you have the installation instructions? You could be putting something on it that would eat the gasket or cause it to fail. I would wait a few hours and see if the A/C expert will post an answer.

[Lothlorian]

The support beams between the skins are in. They are made of aluminum. The hole is 14" X 14". The new gasket fits the hole perfectly. I think I am ready to go. I am doing it tomorrow. I am beat and done for the day. We got the old off without scratching or denting the top.

I guess all I use is the new gasket and fit the air conditioner on without messing up the gasket.

Brian

[Splitrock]

The one I installed last summer was a Duo Therm. I just made a stiffener frame inside the opening, set the unit in place, and tightened the 4 bolts. I tested it with a whole season of thunderstorms with no leaking.

[blickcd]

I did this job a few years ago and will contribute some photos.

Since the old Armstrong unit was screwed down, those holes were reamed out with a drill and plugged with olympic rivets. I removed the old unit in pieces, throwing them off the roof as I went.

The new unit was taken up by myself and a friend using two ladders about 3 feet apart. I had removed the shroud to shed a little weight and so we could get a secure grip on the flange of the base pan. It started to slip forward off our shoulders as we started up the ladders but we toughed it out with some of the weight resting on our arms. A folded scrap of carpet served as the landing pad on the roof. I'm the skinny guy with the 80's hair in the photos, proving it really takes determination to get one of these on the roof and not brute strength.

The new air conditioner's gasket is all that is needed for a seal and no extra caulk. I put some blocking, old strips of lath, inbetween the roof and ceiling skins so the gasket would be compressed tightly. This was only required on the front and rear of the opening as there were existing channels on the sides. The roof insualtion and new mounting bolts keep the blocking from scooting out of place later on. The old drain tube you see was left in place. There is no way to hook it up to this unit that I have discovered yet.

The interior panel had to be trimmed to fit the curvature of the ceiling. Used a hand held hacksaw blade and my results were not perfect, but are hidden on the final installation by some self-adhesive weatherstripping.

Note that the unit installed here was a Carrier AirV heat pump, which is no longer available. That said, just about any other modern AC unit will install in a similar way.

Christopher

[Lothlorian]

Thanks for the pics.. We got the new one on and will wire this weekend. The old air had a hot and neutral but did not have a ground?

Brian

[blickcd]

Brian,

There should be a ground somewhere. Mine was connected to a piece of romex cable, 2 conductors with ground. Maybe your ground is cut off and the insulation could be trimmed back to expose it? If not I suppose you could always ground the new unit to the shell framework.

Christopher

[Lothlorian]

This trailer is 1960 and I don't see a ground for the old wiring. PO but in some newer electrical boxes and used romex which has a ground. You suggested grounding the trailer. Is that what I need to do?

Brian