Crazy AC Idea!

[npllce]

I often like to try new things that no one has tried in the past. I do not know if this is new. Has anyone ever used the existing aluminum base on the old Armstrong AC as a foundation for a new AC?

I have a 1975 Overlander. I know the Armstrong AC is a quality unit but this one is beyond the repair phase. when I was inspecting the AC I noticed the Armstrong unit has a molded aluminum base that is riveted to the roof of the Airstream. The base makes a nice flat foundation for the Armstrong. Has anyone ever removed all the Armstrong parts and reused the flat base?

[Belegedhel]

Hi, and welcome to the forums!

I have never heard of anyone using the base of the original AC as you mention in your post (and I have researched AC installations extensively recently, as I just did that job on my '73). I think it would be WAY more trouble to disassemble all of the original AC components from the base, than it is to just pull the whole thing off. My original AC was held in place with pop rivets and sealant, but I simply hit it with an oscillating tool, cutting through rivets and sealant alike, and had it off in maybe 30 minutes. I put a big patch over the whole area to cover all of the mounting holes, but even that was accomplished pretty quick.

There are some posts where people have gone through extensive rebuilds of the Armstrong ACs--this might make more sense--I have a hard time seeing the benefit of using the base only as you describe.

Good luck!

[npllce]

Thank you Belegedhel. One of the reasons I want to use the original base is because of all the rivets you describe. I was thinking it would be a lot of rivets to remove and then patch or seal all those holes. additionally the Armstrong base appears to be very sturdy and made of thicker aluminum stock making a great foundation that spans across two of the support ribs of the trailer. it is clearly a good base as it has held a very heavy AC unit for almost 40 years and there are no cracks or leaks.

I too have read the posts on folks who have rebuilt the Armstrong AC. I find it amazing they have spent that much time and effort on the roof of an Airstream. I do not possess the technical knowledge to do something like that.

I have done a lot of research on all the air conditioner units. I wanted a low profile unit and so that can limit what is available. I read through many of the excellent posts on AC replacement units. For me I am going to use the RVP Coleman Mach 8 which seems to be a quality unit. It is also the only American made RV AC. This is very important to me as I do not want to send my money to China or Mexico.

[npllce]

So I took the old Armstrong apart one piece at a time. This was actually not too hard. I used bolt cutters to cut through many of the electrical lines (after all the power was off) and I used a metal cutting blade on a reciprocating saw. The good part of removing components piece by piece is that it made it easy not to damage the Airstream. Lifting the old AC in one piece would have been difficult.
When I got to the carcass of what was left I found a lot of aluminum spot welded to the aluminum base. As it turns out the spot welds are easy to pop off the base through the use of a long wood chisel. I originally tried to drill out the spot welds but I discovered there were a lot of them and I would have left my base looking like Swiss cheese. I made sure the cutting side of the chisel was up on the piece of aluminum I wanted to remove not the base I was saving. This worked very well with only 2 errors I would have to patch.
There are some metal studs imbedded into the aluminum base. They were used to secure some of the heavier components of the old AC. I think I will grind them flat and patch them.

[TouringDan]

If you want to see a crazy (and cheap and economical) AC idea take a look at my thread "Dan's 66 Tradewind Improvements" in the Tradewind section. Hey, it works for me.

Dan

[npllce]

Dan I checked out your thread and did not see much on ACs. I looked at all of them Dometic Penguin, Advent Air, Atwood and other models that were too tall. I think most of us know the roof of the Airstream is curved and the RV air conditioners are designed for a flat roof. I know Dometic can add a drain pan that helps out with the Airstream curved roof.

I settled on the Coleman Mach 8 which is a low profile AC. I purchased the one with a condensation pump so the build up of water can be discharged by the pump through the existing drain line in the Airstream. I purchased the AC from American RV Company in Azusa California. They had the best price and selection. They could not get the 15,000 BTU model with the condensation pump in white and they said Coleman only offers it in black. They had to special order my 13,500 BTU in white with the condensation pump. I was going to go with the analog thermostat but because I was putting a heat strip in as well the thermostat required 6 wires instead of the 4 wires in the factory AC. I would have had to remove a lot of the ceiling aluminum to run the correct wire. I did not want to do that so I purchased the set up without the wall thermostat. American RV and Coleman are great at customer service. Coleman will bend over backwards to help you with your project. They have all there instillation and owners manuals on line and when you have a question you get a real live American to help. They also have installation videos on there web sight and on You Tube.

As you can see in the photos I was able to salvage the base or foundation of the Armstrong AC. It took some work and some patching of the front of the base where the 14" square hole was not the right dimensions. I was able to patch that and seal up the rest of the base and now I have a nice flat, strong watertight foundation for my new AC.

[jdalrymple]

There is a thread somewhere that documents the complete upgrade of an Armstrong unit with all new parts.

As I recall, the fellow even included reversing valves to add heat pump operation.


Regards,

JD

[Aage]

Probably too late for you, but here's a thread that takes the old Armstrong and makes it dance to a new drummer.

http://www.airforums.com/forums/f427...dor-76432.html

[npllce]

Yes it is too late for me and my project. I looked at the thread and it is quite impressive. I know after taking my Armstrong apart it had many problems that could have been fixed but it would have taken many days and the total cost would have exceeded buying a new Mach 8. The heat exchangers (coils) were filthy and required disassembly to clean. All the insulation that was glued to the inside of the aluminum panels had failed and the insulation was loose inside. The aluminum duct work had gaps that let cold air out. Both electrical motors and the compressor would have to be replaced.

The next part of my project will require me to shore up the 14" by 14" opening for the AC. The photo is taken pointing toward the front of the trailer. The gap between the roof aluminum and the celling aluminum needs to be enclosed and strengthened. I noticed many folks make a square out of wood to seal and support this area. I am looking at a way to make it stronger.

The electrical power comes from the driver's side and so does the drain tube. In the front piece of wood I think I will drill a hole at a sharp angle so the Airstream drain tube will naturally point toward the curb side. The curb side is were the Mach 8 condensation tube is located.

[TouringDan]

npllce

Sorry I sent you to the wrong thread. I actually wrote a separate thread about installing my 5k AC unit in the window that I power with my 1000 watt gennie. It is in the AC section. You can find it if you click on my name, then click on statistics and then click on threads started.

Hope that your project works out.


Dan

[npllce]

As I was inspecting the void in between the roof aluminum and the ceiling aluminum I can see the rib supports are about 2 feet apart. I noticed the air conditioner will be much more secure if I attach the wood to the ribs. The wood supports had to be notched to allow wires not be pinched or smashed. in the picture you can see I cut the long pieces of wood to run front to back. I notched the wood to sit on top of a lip on the rear rib. The front rib will be attached by a screw into the rib. I will also screw the short pieces of wood that go side to side into the long pieces of wood thus making the 14" square. I think the wood supports will give much more rigidity than just making a square that does not attach to the ribs.

I also drilled a hole just big enough for the condensate tube to fit through. I made it a very sharp angle that will allow the tube to be directed to just the right spot to be tied into the new AC condensate tube. I also drilled a hole for the electrical wires to go through. Again I measured and drilled the hole at the exact spot it would hook into the junction box on the new AC. While I was at it I drilled the holes and used a countersink for the screws that would bind the entire frame together.

[npllce]

My Overlander is stock for the most part and the Armstrong AC was original as far as I know. I am the third owner of this Airstream. The odd thing I noticed while preparing for the wood supports. There was no fiberglass insulation in a large part of the void under the AC base. So as I install the wood supports I will install insulation as well.

The wood supports went in well and I used small black straps to pull the wood into place to get the screws driven with out the wood moving. The photos are kind of dark but you can see where the electrical lines come out and the black drain tube comes out at a sharp angle. I was able to put a fair amount of insulation into the void as I placed the wood. This should make the AC somewhat quieter and the Airstream more energy efficient. So far so good.

Next up will be lifting the Mach 8 onto the roof.

[npllce]

I had thought for some time the best way for me to get the Coleman Mach 8 to the roof of my Overlander with out damaging the AC or the trailer. I have viewed on the forum many ways folks have used. I have a large garage I can pull my trailer into. I decided to screw in some anchor points into the rafters and lift the AC with a rope hand wench.

The Mach 8 has a fiberglass bottom and it is somewhat flexible. The sides are the shroud that is not designed to take a load. I used straps to spread the load out as not to put too much pressure in one area. You can see this in the photo. This set up worked well. One added item I should mentioned is a tag line attached to the strap to steady the AC and keep it away from hitting the Airstream.

Once I had the AC on the roof sitting just right on the flat aluminum foundation I salvaged from the Armstrong I noticed the foam pads on the bottom pan of the AC were not all the way on the foundation. They needed to be moved about 4" forward. I was able to move them on the roof without too much difficulty but I should have measured beforehand and done the relocation on the ground.

The old foundation proved to be an excellent mounting service for the new Mach 8. It was flat and firm without week spots or flexing. You can see from the pictures that the Mach 8 sits toward the back of the flat foundation. It is not exactly in the middle front to back wise but side to side it fits perfectly.

[TouringDan]

Mach 8 installation looks great. Very creative use of the old Armstrong pad.

Dan

[cwf]

Nyce, very nyce!

[amazongb]

Looks great, nice work!!

[npllce]

Finishing off the inside has posed some of the same problems the outside can. As we all know the inside ceiling is curved. One of the good things about the Coleman Mach 8 is the inside trim comes with extra screws that can help make the plastic conform to the curve of the ceiling.

By the time I was done I was able to keep the ceiling gap down to less than 1/4" as you can see from the photos. If you screw the plastic vent down tight enough you can make it so there is no gap anywhere. The problem is that it causes the filter door to be smashed and it will not fit into the designated area. I was able to trim the door slightly and found a good compromise.

I have used the Mach 8 a number of times now and I like it very much. The inside noise level is the same as any other AC. Outside the fan noise level is louder than some others. This is because of the low profile design and small area used for a fan area required it to blow out more hot air from a smaller area. Thus more noise. I find it to be a minor distraction. Most of the time when you are out camping you are not sitting outside visiting with the AC running inside. Well that has been my experience anyway. Good luck on your projects.

[cwf]

Question now is, "how well does it cool?" Don't forget a bucket under condensate line. You can time the run and get idea of how well it removes water from air

[npllce]

Originally Posted by cwf

Question now is, "how well does it cool?" Don't forget a bucket under condensate line. You can time the run and get idea of how well it removes water from air

Well I can tell you it has been about 100 degrees around here and a good time to test my new AC. It works very well with very good air flow that blows strong all the way to the bathroom and front seating area.

The inside temperature of the trailer was 95 degrees and I had it down to 70 degrees in 20 minutes. Also the condensate pump works well too. We usually do not have much humidity in this area but we did the other day when we had some thunder storms. The pump worked great. I am very happy with the Coleman Mach 8. It has my recommendation.