Prewar car air conditioning tips

[Den41Buick]

Does anyone have any neat tricks from keeping your shoes from melting to the floorboard, or for sticking to the seats during hot and humid summer days in a prewar car? Open or closed the cars are a sweatbox in the summer for those of us who grew up with A/C. And by the way my cars are black and dark blue which does not help at all. All suggestions welcome! 

[Matt Harwood]

Insulation is the best bet. Most of the heat is [obviously] radiant heat from the running gear, with heat from the ambient air being a distant second. There's probably a 20-degree difference between the front seat and the back seat of my 1929 Cadillac on a hot day. The only insulation it has is that the carpet extends about halfway up the firewall. The floors are wood, which probably helps, but even at that a previous owner glued styrofoam sheets to the underside of the floors. Looks like hell but might help a bit.

 

My '41 Buick is better, with a purpose-built jute insulation barrier which I'm sure your Buicks have as well. It's OK and better than nothing, but the materials they used in 1941 weren't exactly state-of-the-art. Sadly, the best insulation is air, and to get good thermal breaks requires a lot of still, non-moving air, which is how fiberglass insulation works. Can't exactly do that on a car. Second best is to reflect the heat, and that's why you see a lot of aluminum foil type barriers with a secondary insulation layer attached. I might recommend doing some research on various insulation materials and see what might work best. I know Dynamat is the biggest name in such things and they have some thermal barriers, but most of their products are aimed at NVH reduction, not necessarily temperature management, although they may do both. LizardSkin makes a spray-on material that is supposed to a thermal barrier which might be a good solution in hidden areas like doors, floors, and behind that firewall mat in your Buicks. It probably looks like spray-on bedliner, so it's not good for visible areas. There are many other products, those are just the ones with the big names.

 

Whatever you do, it'll still just be incremental, not a major improvement. After insulation, airflow will be your best friend. On the hottest days, I open up the vent windows all the way so they act as scoops to force air into the interior, along with the cowl vent. As long as the air is moving and you have some thermal break from the working parts, you'll be relatively comfortable. Just remember the poor saps driving these cars when they were new in suits and ties and hats. I bet they were SWEATY!

 

Prowl around on Google looking at things like "automotive thermal insulation" and search terms like that and see what comes up. The right product is important, because not all these insulation products do the same thing. Share your results!

[Grimy]

For sedans, be sure to open rear vent windows/quarter windows, and roll down the rear door windows about 3 inches (not fully open).  While you are moving, this creates an air flow with a bit of vacuum.  Individual front carpeted floor mats from Advance/O'Reilly/Pep Boys, etc.), trimmed to fit, serve to insulate your feet somewhat.  No help in parades or when moving slowly, but works well on tours.

[kings32]

What I did to my prewar cars was wrap the exhaust pipe from the manifold to the muffler  with exhaust wrap . You can get it from speed shops or summit racing . Works on my cars .    Kings32

[gregleck]

You can also add low tech air conditioners, but they work only when you are moving.  They were a popular after market item before WW II.

 

Basically a tube filled with ice which hung outside the window, vented through the open window.

[Mark Shaw]

Prewar heaters and car coolers...

[Marty Roth]

is there a source for 6-Volt compressors and evaporators?

[Guest]

If you have a crank up windshield (Fishers was VV, vision ventilation) don't crank it above the level of the dashboard.  It may feel nice for the wind to come straight in on you but if the air goes down behind the dash and then past you and out the rear quarter windows the car will be cooler overall.

[ricosan]

For a quick and cheap way to get a little relief from the heat generated by the engine compartment I bought some foil sided insulation wrap from Lowes.  I don't remember the price but it was very reasonable.  I cut out a section to fit the floor evenly from side to side.  It my take a couple of pieces. Tape them together.   After cutting them to size, I glued the piece to the back of the floor carpet with 3M adhesive spray..

I've removed them and put them back in a number times since and it's still holding up well.  

 

King, I'm curious how much relief you get from taping the exhaust pipe.  Muffler?

 

ricosan

[Restorer32]

I guess after years riding in a buggy with your face just feet from a horse's butt on a steaming hot day the heat coming off an engine just didn't seem all that bad. Hard to believe heaters and air conditioners were ever just an option.

[Janousek]

Their isn't a source for 6volt compressors.  Prewar A/C for Packard and Cadillac had the owner remove/install the belt in the spring and fall.  Packard in the early 50's supposedly but I've never seen one.  Going 12 volt is your best bet for A/C.  

 

Lizard skin is your best bet for insulation.  From the products I've used nothing comes close to it's ability to stop radiant heat.    Spray the floorboards and ceiling.  

I then follow that up with foil backed with 3/8" jute.  The dynamat products are nice for sound deadening but they really don't do much if anything for heat.  

 

Wrapping the exhaust can be effective also.  My wife's grandfather had a 40' Buick convertible that would get so hot on long drives that it would be miserable on your feet.  We have products available to us now that pretty much eliminate most of the discomfort.  

[Den41Buick]

Janousek,

What is lizard skin? Do you find it in hardware or auto parts stores?

[Matt Harwood]

http://www.lizardskin.com/

 

Apparently available through Summit Racing and Eastwood. Note there are two products, one for heat and one for noise. Lots of good information on their website.

[rsb]

A quick google turned up this: http://www.retroair.com/prewarcarac192050s.html

 

[Dynaflash8]

If your car is a Driver, not a show car, Classic Auto Air can custom design air condition to fit just about any car.  Someone I know here in Florida had such a system designed for a 1938 Packard coupe.  It works great.  There was a little engineering involved to make brackets for the small Sanden compresser and new ones for the alternator.....yes, alternator had to be used.  On this car it was not necessary to change the radiator, but on a Buick I think you'd have to go to an custom radiator.  The inside unit was customized to be so small that it fitted up behind the dash; however he had to do away with the factory radio in order to have room enough for it.  As for the 12v, the guy involved is an electrician by trade.  He wired the car so that the lights, gauges and stuff still work 6v by using some kind of a resistor to step the 12v down to 6v somewhere in the line.  I have no idea how he did that, or where he put it into the line.  Classic Auto Air is in Tampa, FL.  I do know he took the car there so they could take measurements to figure out how to customize the inside unit.

[Janousek]

Heres is a quick non auto testiment to LizardSkin.

 

I built an outside woodburner about 7 years ago.  I epoxy primed the outside and applied lizard skin to the entire outside including the door.  The door is just a hollow door made some 3/8" plate making a box on hinges.  I ran the stove the first year but a design flaw made me have to reweld some of the door.  I had to remove an area of LIzard Skin from the door for rewelding.  This area of the door is so hot you can only touch it for a quick second before it's to hot on my had.  The rest of the door is covered in LizardSkin and you can hold your hand on it as long as you want.  In fact the handle is steel and part of the door covered in LIzard Skin and it never gets hot.    Not Auto related but you get the picture.  

 

I've used both their products for sound control and temp control.  They can be pricey but so it dynamat and they outperform the mat products.  During a build they are quicker than mat products but if retrofitting they can take longer due to masking the car during prep because they spray from basically an undercoat gun.  

 

I've dealt with Classic Auto Air and it's always a good experience.