Rear HVAC install help

[Surfvan]

There is a good chance I am not typing in the correct wording but I've tried searching around and I'm not finding what I need on the forums. If anyone knows of past threads that address this issue I'd love to see it.

Attached is a picture of what my current HVAC setup is in the rear. It completely functions, I just need to disburse the air properly and the previous owner got rid of the parts. I'm not even certain of what I am missing but there are no attachments or vent lines and I'm not sure where to get them and how I would run them behind the walls. I plan on doing plywood over insulation for the walls.

Are there any threads that show how one might run the duct lines in the rear of the van on a home build and what parts I need? Thanks!

[BrianW]

Looks like a Ford factory rear heat/AC setup. I think on passenger vans the air was routed through the side panels and maybe even the headliner? I'd look in junkyards for the original panels and vents. Or just make them yourself out of flex tubing and route it wherever you want.

[Surfvan]

Originally Posted by BrianW

Looks like a Ford factory rear heat/AC setup. I think on passenger vans the air was routed through the side panels and maybe even the headliner? I'd look in junkyards for the original panels and vents. Or just make them yourself out of flex tubing and route it wherever you want.

Thanks Brian, yeah it's the ford factory setup. I was just wondering how people are running them behind plywood. Is that really all I need is some flex tubing? I bought a bung of round ac vents at a salvage yard the other day. They didn't have the rest of the setup.

[larrie]

The ac side runs up to the ceiling through a rectangular plastic tube about about 4”x5”x30” long. The ceiling distribution is integral to the headliner. The tube just connects the fan discharge to the headliner. It is hidden behind the plastic trim.

The heating discharge side connects to the distribution in the driver side plastic side panel.

[JWA]

Duct sizing will be important in order to a) achieve proper space conditioning & b) not stress the blower motor with too much duct restriction.

I replaced the factory system because I needed/wanted the extra space it takes up and I did not want rear A/C. Sadly the Ford system is too prone to leaks in the A/C lines which is expensive to replace or repair. My air flow now is 100% through roof vents I've added to a different type ceiling cover or headliner if you will.

I measured the CFM's of the blower of the aftermarket unit and the factory unit then did as best I could replicating those figures. I ended up with two 3" diameter metal ducts, one is a 90* elbow mounted directly to the blower housing and another about 6' long terminated in another 90* elbow. Both outlets have venturi's obtained from Coyote International LLC: Coyote International Online Catalog---this is one of the larger suppliers to the RV and van conversion outfits.

I used their Part Number 06-2012NS (non-shut off version) along with 06-2012-4 flush mounting retainer.

Since the rear unit was removed insulation was added (all rear glass covered with insulation) and an FRP commercial bathroom/kitchen sheet material applied over plywood for future attachment of various fittings etc.

BTW I completely removed all A/C components and hoses associated with the rear A/C. That was the best for the front-only A/C as it basically becomes just a front-only A/C unit, none of the pitfalls of improper capping of or blocking rear refrigerant flow in any other way.

HTH

[BrianW]

Many conversion vans use a similar aftermarket rear AC unit with ducting and are pretty common to find in junkyards. So keep your eyes open for one of them, too, if you are looking to source ductwork.