102A3 - Heating/Cooling Question

[Doug1968]

Fellows,

I'm moving forward slowly with my bus conversion and now I have the inside of my 102A3 all stripped out and I have completed some initial inspection looking for sidewall rust etc.

Earlier when I had pulled the windows I found that the back panel next to the restroom had some rust areas. It appears as though the vent flap in the restroom had probably spent a good share of time in the open position and allowed water to enter the structure under the window. I will fix this and it shouldn't be a problem.

On each side of the bus there was a ducting system that came up through the floor about 8 feet behind the driver (both sides) and then the air was ducted forward and to the rear of the bus. The forced air actually entered the cabin via a small gap (about 3/16") that was behind the interior side finish panels. This put the flow of air, either heat or A/C coming into the cabin right below the bottom of the window line the full length of the bus, both sides. Seems as though this design would work very well?

I have spent several hours reviewing old posts about heating and cooling. These included discussion about removing the OTR heating and cooling system and using roof top a/c and one of several heating options. It seems as though the factory a/c is hard to beat but people move away from this system due to maintenance costs.

My thoughts are this: It seems as though the full length air ducting system running down each side of the bus seems pretty logical and efficient? Would it not make sense to retain this ducting, keep the OTR heat/air system, and design a heat/air system to use while parked? This system would be located in the bay behind the factory a/c system and be ducted to the same ducting prior to entering the floor.

To keep the systems separated maybe a ducting valve could be used to switch flow to the system in use?

Has anyone done a bus with a split system like this? What problems do you see?

I appreciate everyone's thoughts/comments.

Doug

[Nick Badame Refrig/ACC]

Hi Doug,

I retained my OTR Air & Heat system too. I did remove the factory wall panel ducting as it interfered with my layout.

I fabricated a 4"x6" metal channel on the drivers side of the bus at the floor to duct the OTR air to the bathroom & bedroom.

This duct travels behind my kitchen and provides ample air to the rear of the bus.

I left the passenger side floor supply vent open to the area behind my couch. This helps flow the air to the front & living area

of the bus. It works very well and I'm happy with the amount of air it delivers to the drivers area.

Good Luck
Nick-

[Doug1968]

Nick,

I like your idea of having one side of the factory system serve the back and one side serve the front of the bus.

You note that you utilized a 4x6 channel on the driver side to move air to the rear? Does this channel run from where it connects to the opening in the floor to the back of the bus at floor level or did you run it up the wall and then back?

On the passenger side did you shorten the factory ducting having it only serve the kitchen and the front of the bus?

You note that the drivers area seems to be cooled adequately? Is there another factory ducting on these buses that serve only the drivers area?

Did you keep the factory air returns at floor level on both sides at the rear of the bus?

I have read several of the posts on keeping the OTR systems or not? Seems as though one could keep these systems alive without spending too much money? I have located a shop in Portland that services the bus A/C systems on buses for a local charter company. I assume it would be good to have the system checked over and then regularly serviced?

Often I read where someone has removed the factory system in preparing for their conversion. Are there any components that would be wise to pick up to have as spares?

I appreciate your thoughts and look forward to other input.

Doug

[oldmansax]

Nick, Sean (or anyone else who wants to give it a shot    )

Are you familiar with the gas engine/electric motor arrangement found on small Thermoking refrigeration unit?  I had wondered about using the same type of clutch system to add an electric motor to the existing OTR compressor. If you added and additional control to unload the compressor, ( you should not need the entire capacity when parked) perhaps it could be run with a 2 HP electric motor. I know there would be other things to consider but I am just thinking out loud here......

If you had a 24 volt house bank the condenser fans would run from them??? or perhaps reduce the speed of the fans to match ther reduced the load. I even thought about adding a seperate 110V motor to the condenser fan via belt drive.

Whaddaya think?

TOM

[Nick Badame Refrig/ACC]

Hi Doug,

My metal channel is at the floor level on the drivers side. Once you remove the factory wall ducts, you will be left with

a 5X12 inch supply opening in the floor on each side of your coach. Trial and error will come into play until you are happy

with the air flow. I still have the factory returns up front but, I removed the ramp and leveled the floor leaving a forward

facing return hole that I made a grill for. The rear returns are under my carpet...Lol  YUP! under the carpet! and still work!

The most common components you may need for your OTR air would be, a condencer coil, condencer fan motor, and if you

can lift a compressor, get it!

Good luck
Nick-

[Nick Badame Refrig/ACC]

Nick, Sean (or anyone else who wants to give it a shot    )

Are you familiar with the gas engine/electric motor arrangement found on small Thermoking refrigeration unit?  I had wondered about using the same type of clutch system to add an electric motor to the existing OTR compressor. If you added and additional control to unload the compressor, ( you should not need the entire capacity when parked) perhaps it could be run with a 2 HP electric motor. I know there would be other things to consider but I am just thinking out loud here......

If you had a 24 volt house bank the condenser fans would run from them??? or perhaps reduce the speed of the fans to match ther reduced the load. I even thought about adding a seperate 110V motor to the condenser fan via belt drive.

Whaddaya think?

TOM

Hi Tom,

I have been on that road before... One step better would be to use the whole Thormoking unit!

Now, where to hang one of those baby's...

Nick-