I installed a Vintage Air system. As you have found, there are no direct fit systems. You will need to get a universal fit system. . On the series 1, if you want it in the dash, out of sight, you will have A LOT of sheet metal to cut.
Hey thanks everyone for the info re. replacement units...I reckon it's clearly the way to go to achieve more modern levels of climate control in these cars.
One question though...as I've never had a S1 car with a/c, I'm completely unaware of just how "well" the original a/c system works when it's in proper working condition.
I'm told the compressor fitted to my car is a superior replacement of the original, and is designed to use modern gas, but I've yet to use it due to some missing bits in the system. The mechanic that's doing the engine has told me that the original design is nowhere near current levels of performance found in most all cars, but since I've never had a chance to compare, just how bad are they? ...and are there any component upgrades that will at least improve the baseline performance?
Basically it's down to the fact that before committing to a modern a/c, I need to get the rest of the car sorted....so I'm just curious if the original (or possibly slightly improved) system will at least help cool it down a bit.
Probably the best bang for the buck you can do is fit a modern style condenser (the part in front of the radiator). The design of these heat exchangers has come a long way in the last 50 years and you can expect 30% more heat dissipated compared to an original one. Getting rid of the heat is a major bottleneck to any AC system.
You'll probably have to adapt something from another car or use a universal item, but they are fairly inexpensive, and would be needed no matter what system is inside the car. I'd start with that and see how it performs.
The evaporator was substantially increased for the Mark 2 version of the Delanair units (used 1974-87) from 17,900 BTU/hr to 27,300 btu/hr, but changing an evaporator is a big job.
Jagboi64 is right about the modern condensers being the way to go. To answer your question, the original units (at least the Mark2) were more than adequate. My 1987 all original with the old R12 works great. Note that the original expansion valve is designed and calibrated for R12. My 1979 with modern condenser and compressor but the rest original with R134 works fine except the hottest and most humid days. One modification that makes a huge difference is to have a switch to control recirculation vs fresh air. A quick and easy mod. On the hottest days I leave it in recirculate and if I switch it to fresh there is a noticeable decrease in cooling.
I also put a trunk-mounted unit in my 1967 420 this winter. Here's a good place to start but the short version is there was not enough room to put an in-dash unit in my 420 without serious sheet metal surgery and I didn't want to do that. A huge trunk-mounted AC was the best solution. I was worried that not having cold air blowing on my face would be an issue but even in stop-and-go Chicago traffic I stay plenty cool.
Greg,
It's remarkably similar to an in-dash unit except that you loose some trunk space. I went with the Old Air dual evaporator core unit because I wanted to make sure my car was cold and this unit came with two fans. Interestingly enough the fans look to be the same Spal fan the Vintage Air unit I put in my XJS had only one of.
Here's a picture of the unit. The air intake is in the center, the two evaporator cores are on either side of that, and the Spal fans are on the outsides.
Here it is in place in the trunk.
The kit comes with an air intake grille and two vents - only one of which is visible in this picture.
This car is the 420 Compact Saloon (not the 420G/Mk10) but I still felt like it was a long way from the switch to the blower units. I used 4 relays - one for master power to the relays and one each for high, medium, and low fan speeds. My motto is if it's worth doing then it's worth over-doing.
Here's something different you do with a rear-mounted AC unit. Normally I mount the receiver/drier close to the condenser but with the AC in the trunk you want to put the R/D back there too. This makes sure there is a reservoir of refrigerant.
When I was done plumbing the air tubes, drain hoses, and refrigerant lines I made a panel from plastic and covered it with Hardura.
The control knob for the AC is mounted at the corner of the dash in an unobtrusive location.
I custom-made the AC bracket because I couldn't find a factory one that I liked. While I was here I also upgraded the alternator to a 105 amp GM CS-130. The stock alternator was 60 amps and with the twin fans in the AC unit + two 12" Spal radiator fans I felt this was a smart move.
SOP for up front is the largest parallel flow condenser I can physically fit.
The AC in the back meant that I had to run two lines from up front all the way to around the rear axle. I used VintageAir U-Bend-Em lines as much as I could.
How well does it work? Very good. I was worried that with the unit in the trunk I would feel hot without the in-your-face evaporative cooling that an in-dash unit provides. I shouldn't have worried as there is plenty of cold air moving throughout the cabin. Years ago I had a 1972 XJ6 with in-dash air conditioning (picture below) and this works just as well - if not better - than the XJ6.
My advice is if you are looking to add AC and don't have room in your dash, you don't want to cut your dash, or you can't find an original in-dash unit for your car you should consider one of the modern trunk-mounted units. I would even specifically narrow that down to the twin evaporator unit Old Air sells.
Great write-up. I love it when someone takes lots of photos so it is clear to those following in his footsteps. The '70s Cadillac limos had a front a/c unit and a rear one which I assume was like this.
