Lets talk about A/C

So I got my new tunnel and dog house coming along pretty good. I am going to have to move on to the heating and cooling soon since I will want this in place before I finish one of the sections of my new counsel.

Even though I dont WANT to use the stock heating I may end up having to. I dont have a ton of room to work with under the dash but I am still working on a couple of things so will see how the heating part evolves.

I would like to discuss A/C and while most people dont have A/C in their van this is more of general discussion on the operation of any A/C system and do's and donts on components.

Components...

1. Compressor - Runs off the motor

2. Condenser - Looks like a radiator outside the van

3. Dryer - Round tank

3. Thermal Expansion Valve - No idea what/where this is in the system

4. Blower/Evaporator unit

5. Coolant.

I want to start with 5 since I have seen talk of 2 kinds (R12 and R134?) and R12 is discontinued and so you have to modify your system to use R134? My motor is out of a 1991. What parts will work and what wont with having to use this newer freon or is should my system already be set up for this? Since this is a non conventional system I can piece together from many different brands. Most of the components are very inexpensive, except the compressor. Will or can I make my compressor work with R134?

I am looking around at different evaporators. Is there a certain feature I should be looking for that will make it usable with R134? I have seen some that dont have threaded connectors, I would say this is the wrong way to go.

Dryer, Is this where the system is filled? Does this require the big change from R12 to R134? Year I should start looking for that will be usable with R134?

I dont want to get into a huge debate about how I wont be able to do something, or shouldnt do it cuz it will ruin a stock van, lets face it, the van is no where near stock and I am sure will piss some people off all the modification I am making but it is OUR van. Let me worry about how I am going to fit all this in the van, I just want to know the CORRECT components I will need.

I am sure there are more than a few people that havent seen my tunnel I have been making so here is a picture. I will be mounting the evaporator/blower box near the front wall over the top of my tunnel with hoses to come out the sides of the boxed in counsel and dash. The heating unit will be completely separate.



I have the rear A/C heater unit from the van and hoping that it will work with R134. The rear unit consists of a blower, evaporator and heater core so not much here that should need changing unless the connectors on the evaporator are not compatible with a R134 system.

Mike = look on the rear unit - should be printed there - yet all units can easily be converted to r134 stuff!!- best advice i can offer - look into the complete units from -vintage air , & others too. Vintage air was the origional a/c builders & have made so many diff units & applications - all otehrs have copied over the years - look @ there site online =vintage air.com

Thanks TP but I dont want a pre-fabbed unit. I am not going to have room for it when my counsel is done so that is out of the question.

Do you have more info on what to look for that makes a system R134 for components like the dryer and all that?

This gives me a good layout at least to know how it all must run but it still leaves the expansion valve component in question since I might have missed this when pulling my unit it from the van. I will have to look at everything I have.

Any A/C component designed for use after 1994 will be R134 compliant. The rear A/C unit you have can be converted as long as a flush is performed on it. The same is true for any part you want to use from the other van except the thermal expansion valve, I would suggest replacing that. The high, and low pressure fill connections on your system will need retrofitting as well, there are kits available for that. Hope this helps.

Tom

Tom,

That is GREAT info! Thank you so much!

A question about expansion valves. Are they controlled by something electrical or just something that goes in the line that is mechanically adjusted/controlled?

I did an ebay search on them and what I find is a fitting with a thermo line running from them? Does the thermo line go in the blower box near the evaporator or something?

I should also ask...

In the diagram I posted above, where exactly do the high/low lines connect to the unit or are they tee'd off from the lines shown as high and low pressure?

like tom states - FLUSH!! always use new driers or what ever name component that does the same job! There are seversa -yet "Drier" is the old term. Now im not saying to use a new unit - just go to their site & LOOK! @ what they have to offer? Thye site has thoery & as these guys have forgotten more that most new companys know--- they have all sorts of different units also- Vans and everything else has been done by these guys @ vintage air! they had hidden under seat & upholstery - celing units - small/ large units & dual mount anywhere units. I do understand as u have made a tunnel for ait into the engine area - what ur thinking is -no room ? yet many units can be mounted elsewhere too .Just take a look & see whats available too. Realizing that also you will likely need a larger condenser - with fans to get that heat away from the system & cool a van properly too. VA are the guys & they have so much info online it will take days to digest all there .

I will take a look TP. Thanks as always for your responses!

Since about 10 years ago R134 has been modified and is compatible with any system with no seal or materials changes required. Although it is advisable to flush, the system, change the disacant (dryer) and the expansion valve orifice, then evacuate the system before adding the correct amount of lubricant and Freon.

Note: do not leave any hoses or parts of the system uncapped or open to the atmosphere. Or you will have rapid internal corrosion within days that will cause system failure withing a couple days of use.

M1D

they sure stuck to the people who convetered from r12 to 34 selling them stuff they did not need.in the mid 90,s

Expansion valves just go in the line and perform an orifice type duty, no adjustements or electrical components involved, The high and low pressure ports should be integrated into the lines, and are specific sizes as to not allow inadvertent filling into the wrong side of the system.

Tom

I know this isnt A/C but wanted to ask about a heater core. Does it matter if the hoses are facing DOWN from a core? would be pretty much the core mounted upside down but this would save me a ton of room.

check out proairllc.com They do a/c heat set ups for shuttle buses etc. I talked to them about a/c for my '68 108. I'm also looking at junk yard conversion vans with rear a/c heat.