an idea for A/C
 

I don't know how effective this will be, but I've got an idea. Remove the A/C compressor, condensor, dryer, and all the lines associated with these components. Connect hoses to the evaporator in the dash and run them to the back of the car. Connect a typical oil/transmission cooler to these lines. On one of the lines, run a small 12 volt pump like a Shurflow RV pump. These pull from 4-7 amps of current typically. Fill the hoses up with water or some kind of coolant that has a lower freezing point than water. Put the oil/transmission cooler in an ice chest (err, a cooler) that is filled with a salt water and ice combination. In theroy, this would give you some cooling till the water in the ice chest got above about 40 degrees.


Benefits;

1. A/C compressors often take 5 hp or more to operate whereas this would put a very small load on the alternator. I imagine a drop of 0.5 - 1 hp while this system would be running.
2. The air going over the radiator would be cooler therefore making a larger grill block possible during warm months.


Disadvantages

1. weight. Primarily the weight of the ice. Depending on the size of the cooler, 100 pounds additional weight could be seen. Take away 25 pounds or so for the weight of the A/C compressor, condensor, and the lines and you're looking at 75 pounds.
2. you'd need a very large and readily supply of ice.
3. it won't be as effective as a normal A/C system.



I'm thinking about trying this on my Cavalier. I've already got all the parts laying around, and there is a massive ice machine where I work so I can completley fill a large cooler everyday with ice. The A/C system has already been removed on this car due to the oil cooler adaptor interfeering with the A/C compressor. So, I'm trying to think of a way to get A/C back on this car without putting an A/C compressor back on it.

What do you guys think?

I have considered something like this as well since my Civic didn't even come with factory AC. I saw a little 12v cigarette lighter plug powered plastic ice chest/radiator/fan apparatus in Wal-mart last fall that you filled with ice and the little fan blew the cold air directly on to you- the driver. But it was in the clearance isle so that might be a good indication as to how well it worked in real life.

I think it comes down to BTU's. We'd have to calculate how many BTU's enter a car through the glass/body on a hot sunny day per hour and compare that to the amount of BTU's it would take to melt the ice and bring it up to 40 degrees F.

I think that a better way to do it would be to put an ice vest in the freezer (a vest filled with those blue gel freezer packs) and then wear it over a thin T shirt. That ought to be good for an hour or so of hot weather. Maybe even an ice hat/helmet looking thing. Now that would get me some stares!

pssst they already have those vests that just have water circulating around in em. nascar drivers and the liek wear em.

for AC since neither of my cars have it, is roll down all windows and then drive if not crank the blower on vent, i figure if people could do it before 1950's i can do it...

I agree completely with you on this one. I've only had 4 cars I believe in all of my 15 cars that have had working A/C. I can manage. However, my wife would like this car MUCH more if it was a bit cooler inside during the summer.

yea but what makes AC work is the phase change that occurs as the refrigerant is compressed/expands heats/cools the whole ice-chest thing was done in the days before the air conditioner and it didn't really work then either. just open the windows or get one of those vests

WARNING: BRAIN STORM/FART AHEAD..........................



That is true about the phase change. Hmm, water turns to vapor at 210 degrees at 14.7 absolute pressure. Ok, so if we put water under a vacuum this will lower the phase change point, but by how much? Hmm, a strong check valve on a hose running up to the intake. The entire system would have to be sealed tighter than Fort Knox to prevent liquid from being sucked into the motor. Under deceleration I see 22 inches of vacuum. Or I could get a vacuum pump connected to a vacuum switch so it would automatically turn on when vacuum got less than say 24 inches. The vacuum pump would be able to give more of a vacuum, but would it be enough?

I could put rubbing alcohol in the system, but if there was a leak, that could be very dangerous. Then again, there is gasoline in the car and if there was a leak in the fuel system it could be very dangerous! Now if I ran alcohol and a vacuum pump than this would lower the vaporization point of the alcohol, but I don't think it would be needed. Well, for safety I could have the entire system under the back of the car accept for the two lines going to the front and entering the evaporator. I've got some hoses designed for air conditioning systems. They could handle any pressure, no problem, but how corrosive to rubber hose is rubbing alcohol?


Ok, that's enough of my brain storming otherwise I'll be here all night!

Use dry ice to keep the ice longer. Just a small amount will do it i think. Dry ice, great stuff.

I think you might need a two ton truck to carry ice to cool your car for a days drive on a hot day

^^agreed

just save yourself the time/money/weight in your car and use the g**d*** AC connected to the engine

I can't. There is an oil cooler adaptor connected where the oil filter used to be, but this adaptor is larger at it's base than the stock oil filter. If I were to reinstall the A/C compressor, the lines will not seal properly due to clearance issues with the oil cooler adaptor. This motor ABSOLUTELY needs the oil cooler.



I would not be interested in cooling the car for hours at a time. Just 30 minutes at a time would be enough. I'm also not expecting nor am I wanting a 30-40 degree drop in temps. A simple 10 to 20 degree drop would be enough.

I experimented with this idea today.

I took a cooler I had and put two 10 pound bags of ice in this cooler. I then put a wide window fan on the top of the cooler with the top of the cooler open. The fan was setup so that it blew air out of the cooler. I closed the lid partially on top of the fan which in turn directed air from the fan towards the front of the car. This was sitting in the back of the luggage area in my station wagon.

My 2 sons and I then drove to my sister in laws house an hour away. The windows were up the entire time. Currently there is no window tint on the car so it usually heats up pretty quick in the Texas heat. The outside air tempurature was in the mid 80's with dew points in the low 70's. Needless to say it was VERY muggy. After an hour drive, there was still ice left, but the tempurature in the car had not decreased. It felt to be in the low 80's, about the same as the outside air temp.

I believe if I had the fan blowing air down into the cooler instead of sucking air out of the cooler then it would cool the air off better. I'll try this next week on Tuesday or Wednesday. I'll also grab my digital portable thermostat to get an accurate temp reading. Temps are supposed to be in the 90's next week too so it should be a good test.

My mother told me a story about a vacation she and her mother took in 1937. They drove their '29 Oldsmobile from Lincoln NE to Santa Monica, CA. For driving across the desert, they put some dry ice (presumably in some sort of container) by the outlet for the vent in the car. The incoming air was cooled by the dry ice, making the drive across the desert more comfortable in that pre-A/C era.

91CavGT, your idea, since you have to reload it with ice on a regular basis, seems awfully labor-intensive and ultimately more expensive compared to the benefits derived. But that's just my opinion.

A station wagon is a large area to cool. I'm not surprised that the ice didn't do much. In the '70s, I had a couple different cars with comparable A/C systems...a '66 Malibu sedan which got nearly cold enough to hang meat. Then I had a '65 Plymouth wagon with an A/C at least as big if not bigger...but more volume and large windows on the back. A/C could barely keep the car comfortable. I often wondered about those Plymouth Barracudas with the BIG back windows...

My thought (if I ever get around to it) would be to put together some sort of absorption-cycle refrigerant system, similar to the natural gas Servel-type refrigerators. Using the exhaust heat as a heat source.

Interesting read. My commute in the afternoons is about 45 minutes long and sometimes my wife will be with me. I've got a free and endless supply of ie at work so that's not costing me anything.

Do you have any more info on the absorbtion-cycle refrigerant system? That sounds like something I'd like to read up on.

Just a word of caution for anyone wanting to use dry ice to cool their car- do not just put a couple of huge chests of dry ice in your back seat and roll the windows up. It will sublimate into carbon dioxide gas which could suffocate you if you had your vents in the recirculate position. I'm sure there was enough fresh air coming in to that 29 Olds to dilute the carbon dioxide from teh dry ice.

Erik

Good point. If memory serves, the '29 Olds pre-dated rubber door weatherstrips by about 8 or 9 years. They probably also left a window either cracked or all the way open. I can't verify the precise operation...my mother is no longer alive to ask, and she probably didn't remember all the technical details when she told me the story some 40+ years after the fact...she was 15 at the time and more interested in the fact that Wyoming didn't require a driver's license then and the minimum age to drive was 14, so she could drive across that state herself. She was also looking forward to a summer at the beach...probably thinking about all the guys out there...

91CavGT

There is a good description of the absorption cycle (and yes, it is spelled absorption, not absorbtion) here...https://www.gasrefrigerators.com/howitworks.htm

In theory, something like the absorbtion cycle would be a GREAT idea. But there is one little problem with it: it requires the use of a cooling tower. This makes it rather unsuited for anything but stationary applications.