Silver Beatle - She's now with an old friend!

[lrrowe]

Good luck Tom. Hope you have better success then I did.

[Shadow Catcher]

I used the thermostat from the AC unit mounted in a project box and it works well enough. I was going to use a commercial/industrial using 120AC. I could not get them to play well together and just using the one from the AC was a simple solution.

[aggie79]

With the disassembly of the window unit complete, I wanted to try out the residential thermostat and controls that will replace the electronics that came with the window unit.

Before I built everything in place, I wanted to test it on the bench first. Here's a picture of the 120 VAC side of the wiring. Just to the left of the window unit is the start/run capacitor that came with the window unit.



On the plywood is a 120 VAC to 24 VDC transformer. Behind are two contactors (relays) that will control the on-off of the fan and the compressor.

Here's a picture with the thermostat and the 24 VDC control wiring in place.



It doesn't look too pretty sitting there.......but it works!

Now its on to fabricating the ducts and plenum and starting the build of a new tongue box.

[Shadow Catcher]

It will be interesting to see if you encounter the same coil icing problem I did. One individual went with 5" hoses which seemed to be enough.
Ya done good

[ibbowhunting]

I see you are using two relays one for the compressor and one for the fan are you going to run the fan with the tsat on fan mode, more or less running the fan non stop, and then cycling the compress off and on by temp of the tsat in cooling mode?

[aggie79]

It will be interesting to see if you encounter the same coil icing problem I did. One individual went with 5" hoses which seemed to be enough.
Ya done good

As things are evolving on the design, I'm thinking about a supply duct the same cross-section that it is in the unit. The return duct design still is TBD. I already have a "boost" blower in my galley that I used to push the return air on my Petcool setup. I hoping I won't need this. Tentatively I'm considering a rectangular return duct around 3" x 10". I had the same depth duct on the Petcool and didn't experience any ground clearance issues.


Sent from my iPhone using Tapatalk

[aggie79]

I see you are using two relays one for the compressor and one for the fan are you going to run the fan with the tsat on fan mode, more or less running the fan non stop, and then cycling the compress off and on by temp of the tsat in cooling mode?

I wanted to have the option to let the tstat automatically control the fan when cooling but to also be able to run fan only at times to circulate air within the teardrop when we have the windows and/or roof vent open.


Sent from my iPhone using Tapatalk

[ibbowhunting]

so does the fan motor have multiple speeds or is the speeds controlled by the fan switch some how, just thinking with a small rely you could run the fan on a low speed for circulation and the fan speed could automatically ramp up when the compressor is running, not trying to pick apart your design, I think your on to something, and I still have to build an A/C Set up and I'm liking your control design

[aggie79]

so does the fan motor have multiple speeds or is the speeds controlled by the fan switch some how, just thinking with a small rely you could run the fan on a low speed for circulation and the fan speed could automatically ramp up when the compressor is running, not trying to pick apart your design, I think your on to something, and I still have to build an A/C Set up and I'm liking your control design

The factory switch has five positions - high fan (only), high cool (high fan & comp), low cool (low fan & comp), low fan (only) and off. The compressor is a single speed and has only one hot lead. The fan motor has two speeds with two hot leads.

I will probably put all of the controls in a project box next to the unit. At this time, I will probably place a SPDT on-off-on switch on top of the box so I can manually select fan speed. I really only see the need to use high fan when we first set up camp on a hot day. After the initial cool down, low fan speed should be more than enough to maintain temps (unless I get icing but I'll cross that path when I come to it.)

[ibbowhunting]

here's a thought hook the high speed fan tap to the compressor relay, hook the low speed fan up to your fan relay, install a small 24 volt relay, that will break the fan call when the a cooling call is present
so the fan will either run on low speed with a fan call from the tsat or be off until the tsat calls on the compressor, I could be wrong but i'm thinking you will be icing up with the compressor running and the fan on low, but I like the idea of the fan running at a low speed circulating air deicing the coil if ice is present between compressor cycles or just circulating air, just a thought, either way I like your plan on controlling the A/C unit

[aggie79]

I found a few hours to start the sheet metal work of the window unit hack.

Here is the cut sheet metal ready for bending:



Ready for the first bend:



Everything seems to be straight and square:



Partially complete plenum mocked up to unit:



Because this project is an "on the fly" design and build project and because I've never done a sheet metal please keep in mind that the above might be nothing more than a prototype and be scrapped.

[ELM]

That looks great for a first attempt at sheet metal work.

[aggie79]

Well, I've messed around on the HVAC upgrade long enough that it is now the height of camping season. The upgrade is not finished, but we have an outing in two weeks, so I started "buttoning up" the HVAC redo to get ready for camping.

But...since I already had the teardrop up on blocks, I decided to do a project that I've been putting off for a couple of years. When I was thinking about how I wanted to build my teardrop, I thought I wanted to be "low slung", so I ordered Dexter Torflex torsion axle with the start angle of 10 degrees up (spindle center above the center of the pivot point). Most of the builds I've seen had the start angle at 10 degrees down or higher. The 10 degree up start angle resulted in a frame to ground clearance of about 12". On highways and flat roadways this clearance has been fine, but when we came to dips, swales, or a moderate to steep angle of approach the clearance was less than what I felt comfortable with.

So...I ordered a Dexter lift kit for the #9 torsion axle and... then it sat on the shelf for a couple of years. The lift kit is a spacer that fits between the frame bracket and axle mounting bracket. It raises the frame clearance about 2".



Today I installed the lift kit. It was one of the easiest upgrades that I've done and I don't know why I put if off for so long.

Here's the before picture:



First step is to loosen the two bolts on each side connecting the frame bracket and axle mount and lower the axle on one side:



Next step was to install the spacer to the frame mount and axle mount.



I left the bolts loose until I installed the spacer on the other side. Then I snugged up the bolts, making sure everything was in line and aligned, and torqued the bolts to spec. This only took about an hour to install. I don't know why I waited.

All that is left is to install the wheels and tires and we'll be ready to go camping (without the HVAC upgrade finished.)

Take care,
Tom

[dmdc411]

Isn't it funny, something so easy, can sit on the shelf because you just don't want to deal with it!! Then when your done, wonder why you didn't do it sooner!

[KCStudly]

Here's hoping that the tire fit to the fender still looks good once it is back on the ground. I'm guessing that it will!