mci9 heating and A/C ducting diagram

[grantgoold]

Folks, I have looked at both my repair manual and parts manual looking for some type of diagram on the heating and AC ducting. I cannot see one. Does anyone have a copy they can send my way or lead me to a page number in either manual?

Best wishes.

Grant

[chazwood]

I don't ever remember seeing a duct layout in any manual I have.

[oldmansax]

I can't find any in my '7 manual either

TOM

[Jerry32]

I havn't seen any diagrams either but the supply ducts are divided in the rear and the bottom half besomes a return that is carried up front on top of the main conduit of lines . supply is up by the windows and front return is on the floor in the ramp area. jerry

[chazwood]

 This is the way I see it....with the exception of the two fresh air intakes and the two big supply outlets, every other vent on the bus is a return, including the ramp. Every vent in the back is return (4), the first two vents in the front area are returns and every vent in the ramp is return. All returns travel through vents and short hoses near the walls into the middle channel and go the length of the bus. (Except, of course, the ramp.) This whole system becomes clear when you take off the stainless duct work (full of human hair) at the floorboard and rip up the floor.


It's tricky inside that Stainless steel (human hair collector) floor board duct work because it has it's own set of aluminum dividers that divert the air into either supply up the walls or return into the floor vents. This is not obvious until you remove it.

On the supply side, all heat/air comes out of the floor from only two holes (from the two biggest vents about 7 ft behind driver) and is distributed throughout the bus via that stainless steel ducting along the wall ( human hair) at the floorboard and up through the double walls to under the windows.

The two fresh air ducts (the holes closest to the big outlets) move fresh air from outside, directly into the return air stream.(open and close them in the bay)

So under the floor almost every inch of ducting you find is return.

Down in the bays, the top section of flimsy steel right up against the ceiling is return. (the section below that is a wiring and hose chase...don't cut into that.)

The two Air/Heat supply duct vents, in the floor, are short, fiberglass, square cone shaped ducts that go straight down and if left uncovered, make great places to play accidental putt-putt bus golf with every tool, role of tape, water bottle, and stray sock on the premises.  (If I could putt that good in real life I wouldn't be the one converting this bus.) Not to worry .....if you drop anything lighter than a bowling ball down there , the fan is so powerful it will blow it right back out.   (On one trip, we made the mistake of partially covering this vent with a mattress....when I hit the switch, it stripped off the sheets.)

There you have it....clear as mud.

[buswarrior]

Hello.

Perhaps the detailed diagrams in the Body section of the Parts manual might show the detail of the floor and wall assemblies...

I know I've seen it somewhere, manuals are not at hand. Darn where are the spare copies...?

happy coaching!
buswarrior

[grantgoold]

Are we saying the there is a return duct inside the main center channel that you can access in the middle bay on the drivers side. If I was trying to get recycled air into the AC system could I attach a six inch duct work and use this as recycled air?

Thanks

Grant

[chazwood]

The top section of beam, in all three bays, on either driver or passenger side, is return air.


The bottom section is a front to back wire and hose chase.

[grantgoold]

Now we are talking!!! I will get into the channel and see how I can tap into this return line and use it to recycle cool air into my basement AC system.

Thanks chazwood!

Grant