# Air-Conditioning Options



## JRP3 (Mar 7, 2008)

I wonder about the suggestion to use a 12 volt motor for the A/C compressor. The vehicle linked to uses a 180 volt motor running from pack voltage. I don't know if a 12 volt motor would have enough power, or draw too many amps, plus you get conversion losses from the DC/DC converter.


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## eric-ev (Apr 28, 2009)

I'm pretty sure the only 'right' way to retain AC is to use a dual shaft motor (one with a shaft off both ends), and hook the pully up to that. Practically lossless, unlike DC converted from the pack!


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## JRP3 (Mar 7, 2008)

Well there has to be some loss from the belt running around the pulleys and clutch even when disengaged, though I'm not sure how much. Also the A/C stops when the vehicle stops unless you hold the throttle, and not all motors, (like mine) have dual shafts. I think a pack voltage motor might be a good solution.


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## eric-ev (Apr 28, 2009)

I suppose there would be some loss from spinning the clutch and pulley, I imagine it would be less loss than converting that many amps to 12v though.
The plus side would be the converter you can just switch off.

Personally I wouldn't be concerned about the pump not running at stop signs or whatever, whenever the car was in motion it would be spinning the electric motor through the drivetrain, powering the AC, and actually capturing a bit of power via 'regenerative braking via air conditioning' 

A motor on pack voltage would be the 'correct' way too, provided it was sized correctly. 

Anybody have any idea how we'd select the right rpm/power motor for the AC?


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## JRP3 (Mar 7, 2008)

I haven't found solid numbers on A/C hp requirements, I've seen between 3-12 hp mentioned which is a large range. I think some people have used treadmill motors but don't know if they are appropriately sized.


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## rmay635703 (Oct 23, 2008)

Although not the strongest why not use circa 1920's technology?

Passive AC does work but would present an aerodynamic issue. (a big 2' tall 4'x4' dome) There is a place here in Wausau WI working on selling passive portable refridgerators for developing countries, I would assume this same technology would work on a car, insulate the roof, put on a big screen magnifier over a nice set of black AC lines. THe sun compresses the refridgerant and cools the other side.

I doubt it would be strong cool but it would gently cool the roof area.

Now lets see if I can find the joints name, at the moment they are still in the business incubator. Their initial designs were marketed toward large scale business AC, minimal energy needed to make the hi-tech version operate.

Cheers
Ryan


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## few2many (Jun 23, 2009)

When you drive an ice car with the ac on, and then turn off the motor, do you occasionally hear a sound from under you're dash or hood? That's the sound of the ac system equalizing pressure through the expansion valve. The high side, high pressure liquid is vaporizing in the evaporator and settling on the low side. the evap will usually be able too cool for a minute or so after the engine shuts off. On an e car, I would run the ac off the traction motor, install a larger receiver to hold a little more liquid freon and a larger accumulator for added low pressure space. When you're motor is off, at a traffick light, there should be enough to keep the ac going for a few minutes. You want someone to carfully calculate the charge, as this is a high pressure system and if you're accumulator is too small, you'll hammer the compressor with liquid, which destroys it. Remember, not only do you have to somehow power the ac compressor(seperate motor, traction motor, or motor compressor packaged unit) but you also have to run the electric fan that pulls air throught the condenser, these usually draw a lot of amps. Ac is a luxury and in arizona, it'll have to be a reality!


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## dogshed (Dec 25, 2009)

What about thermocouples?
Anyone got any extra electric coolers?
They can also reverse for heat.


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## dogshed (Dec 25, 2009)

Here's a company I found.
http://www.thermoelectric.com/2005/pr/ssac/index.htm


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## few2many (Jun 23, 2009)

I thought thermocouples were too inefficient? maybe ok for heat, but to cool?


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## dogshed (Dec 25, 2009)

http://www.myettnews.com/2009/05/ba...er-bunk-ac-offers-5000-btus-of-cooling-power/

Sun Power Technologies has launched the Sunspot 5000 in-cab, an under-bunk 12V-DC air conditioner that delivers 5,000 BTUs per hour of cooling capacity, its maker said. The self-contained system’s compact design is versatile enough for almost any under-bunk retrofit application and offers easy installation, according to the manufacturer. Weighing 67 lbs. installed, the system utilizes a hermetically sealed 12-V DC compressor and 12-V blowers and controls with complete circuit protection. It draws 50 amps.


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## justanothernoob (May 22, 2010)

What about something a little simpler? Think absorption refrigeration. I know from experience that about 200 watts will get you quite a bit (?) of cooling power. The challenge would be getting existing cooling units to fit in a car- locating the coldplate in the existing cabin air system the biggest I can think of.... I do know theres a rebuilder in Oregon that might be able to modify an existing cooling unit to make it more installable in a car... could be a great savings of power if done right. Also check out the Einstein refrigeration loop. There a fellow at Oxford (http://www.guardian.co.uk/science/2008/sep/21/scienceofclimatechange.climatechange) who has revisted it and claims to be able to quadruple the output from the system from tweaks and going from the conventional water ammonia solution to a butane ammonia solution. Solar or waste heat could easily drive the system at that point! Anyway just a thought to ponder. Dennis


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## IamIan (Mar 29, 2009)

thermo electrics are themselves less efficient directly.... but there are side issues... that might tip the scale in some cases.

Thermo-electric devices can be put in series up to the main pack voltage ... thus the only losses to get the energy to the thermo electric device is a high efficiency PWM to control current flow... or just scale it so you are happy with it at one power level then no PWM is needed.

A simple high efficiency PWM will easily be as efficient if not more efficient than the main EV motor controller.

running anything off the main drive motor would also include the efficiency losses of the motor itself + connecting belts and such.

So the Thermo Electric itself is less efficient ... but power can be supplied to it more efficiently than driving off the main motor ... or going through any type of electric motor driven compressor.

So TE system:
Main Pack = ~99% energy applied to much less efficient TE device for AC.

vs conventional AC compressor systems:
Main Pack - efficient Motor controller - efficient motor = less energy applied / less efficiently used energy .... to a more efficient itself AC system.

- - - - - - - - - - - 

The other side of Thermo Electrics is

They are solid state devices with no moving parts.

They are themselves flat and relatively thin ... thus some creative packaging options become available ... the volume of a compressor is not needed.... just the a TE radiator / heat sink and a moving working fluid / gas.

TE can also run in reverse... not just to Heat instead of cool ... but to generate power instead of consume it.

One of the crazier Ideas I had once upon a time ... was to install the TE radiator on the roof of the cabin ... but under the shell so as to not mess up aerodynamics ... than when the car is parked and the sun heats up the cabin and the cabin's inside temperature gets hotter than the ambient outside temperature ... the TE system could produce some small amounts of energy conversion and turn some of that car heat into energy .... than when I want it... I can throw PWM main traction battery power to the TE system to get cool air... of course only on those days the inside gets 20+ deg hotter than ambient.

One more thing for a TE system ... they cost more $$$ than conventional AC compressor systems.


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## 9852 (Jan 17, 2010)

cloud electric sells an ac system that can attach to your car's existing dash system for 450 bucks, all you need to do is get a 1000w inverter to operate it and power the inverter through the accessory pack. the fittings can be made at any local line shop. and it installs in the motor compartment.


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## few2many (Jun 23, 2009)

Well, noob, the only problem with that is the fact that amonia will kill you or cause brain damage, should the be any kind of leak.
They were used for a short while as ac units, but never really caught on.


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## 9852 (Jan 17, 2010)

dont know what you mean with amonia, they use freon, same as the car, and just as safe. its called cool blue, its made in flagstaff, here is the link
http://www.electricbluemotors.com/products.html,


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## Amberwolf (May 29, 2009)

eric-ev said:


> I suppose there would be some loss from spinning the clutch and pulley,


Why not stick the clutch at the CE shaft instead, so you're only driving a part of that pulley, if it's the only thing being driven by that belt anyway?

Save you a little energy when you are not using the AC, especially for extended periods like when it's winter, etc.


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## JRP3 (Mar 7, 2008)

billhac said:


> dont know what you mean with amonia, they use freon, same as the car, and just as safe. its called cool blue, its made in flagstaff, here is the link
> http://www.electricbluemotors.com/products.html,


Actually I don't think Freon, (R12), is allowed any longer, it's probably R134 or something. As for the electricblue products, they look like a total ripoff to me. Their heater is a $35 Katz block heater and a $45 pump, just like I have, and they want $375 for it, PLUS you have to buy a $500 inverter since they didn't convert it for DC! Their AC units also need this inverter, probably because they look like compressors from home AC units!


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## 9852 (Jan 17, 2010)

you are absolutly right but the title of this thread is Air-Conditioning Options, I know that it is an ac and not a dc compressor. but you dont need to buy their inverter, the unit pulls 4 amps continous and about 10 on start up, so a 1200watt inverter would run it great, and can be bought for 120 bucks at inverters r us, now it will take a lot of power, but change the accessory battery to a deep cycle 120 amp hour and it will be good for a few hours. I do think that the other stuff can be gotten cheaper elswear, but people spend thousands on there conversions, with that in mind I think that is a great way to get ac in you ev for cheap and Im all about that. if there is something else I would love to hear about it, so that I can buy the one that is the cheapest for my ev. after all it is hot here in phoenix.


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## 9852 (Jan 17, 2010)

as too what they look like, they do look like maybe a small modified window unit or something, but when it is installed under the hood after a little planning I think it would blend in nicely


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## JRP3 (Mar 7, 2008)

My point is if that's what you want I think you could go buy a window air conditioner unit for less than that and take the compressor out of that. You'd have the same thing. Better yet find a cheap used one and do the same thing.
http://www.walmart.com/ip/Frigidaire-5-000-BTU-Mini-Window-Air-Conditioner/14254284


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## 9852 (Jan 17, 2010)

I thought of that, but I think that the freon is different then what is used in home ac units, so I dont know if it would work.


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## 9852 (Jan 17, 2010)

but with a window unit how would you run it through the evaporator in the dash, with this unit you can do that, fairly easy.


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## JRP3 (Mar 7, 2008)

From the look of it I'm fairly sure all they are selling is home AC components, nothing fancy. You still have to buy and make your own hoses to connect to your cars existing evaporator, and you need a decent amount of room with good airflow to use their condenser. Their installation manual talks about using R12 which hasn't been used in AC systems for years as far as I know.
I think you could take the compressor from a home AC system, plumb it to your existing condenser in the front of the vehicle and then to your evaporator, all for the price of some custom hoses and a charge of refrigerant. I don't think they offer anything more than a home AC unit minus a few components, and maybe two fittings on the compressor. They even say in their instructions you have to get custom hoses made up on your own.


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## 9852 (Jan 17, 2010)

yes I did see that, but lets say that i went and got a small window unit and bucthered it that way, can i use something like r 12 or preferably r134 in the window unit compressor, because that would make a lot of difference if I can, but i think that the one that they offer will use the r134, it says it uses r12, but r 134 is the substute for r12.


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## JRP3 (Mar 7, 2008)

If as I suspect they are simply using home AC parts, and if as they claim you can use R12, which would now be R134, then I'd say you can do the same with your home AC parts. Might be worth talking to an actual AC pro to be sure. I think R12 systems are supposed to be a bit less efficient when changed to R134 but I did one and couldn't tell the difference.


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## 9852 (Jan 17, 2010)

I do think its worth asking a few questions, like the freon issue, and also if it can be converted to run on dc voltage.


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## EV-propulsion.com (Jun 1, 2009)

most home air conditioners (central or window) use r-22. As JRP said, R-134a replaced r-12 years ago as it was blamed to deplete the ozone layer and it was banned to manufacture it. If you were to use this unit, it would more than likely need r-22. (which btw, both r-22 and r-134a are planned to be replaced also with more envionmentally friendly gas, possibly CO2) Also by the way, you need a EPA license to purchase R-12, and technically a special class of the EPA license to fill this unit in a vehicle.
Mike
www.EV-propulsion.com


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## 9852 (Jan 17, 2010)

maybe where you are but not in phoenix, you can buy r134 at autozone and if it would work with 134, there are no ev regulations about air conditioning in here, other than the r12 ban, as long as the air bags, lights horn and turn signals and wipers work you are good to go. as a matter of fact I drove the car down to be inspected and the inspector looked at the motor, lights beeped the horn turned on the wipers, and said yep Its an alternative fuel vehicle, and charged me 18 bucks for 2 years to register it as such, so its as leagal as they come.


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## justanothernoob (May 22, 2010)

Ok.... I see that one fellow thinks that ammonia charged systems are deadly... oddly enough they are in use by the 100's of thousands everyday in your typical RV refrigerator. Lots and lots of HOMES use them daily in European and other countries where energy costs are high as it is a very low energy option to refrigeration as it involves NO compressor. I suggested it as a low power alternative to the issue of air cooling the cabin in an EV.

As to using a home window a/c unit, I do believe with a lil smarts one could run most hermetically sealed units on the proper amount of D.C. voltage as they are using universal motors in them. The real problem lies in controlling the unit as the controls do use A/C power to function. One could easily use a small power inverter to power up the control side while using a relay and pack power to run the compressor. 

An easier alternative to this would be to use a RV roof top unit that uses a remote low voltage D.C. controller. It would be basically plug and play for the interior cabin controller, all the design issues being 1) ability to plumb the heat exchanger into the existing system or 2) trying to mount/duct the unit as built into the cabin.

Honestly, if you really desire air conditioning and the car had it to start- I do believe a separate motor to drive the old compressor is all one needs. 1/2 hp to maybe 1 hp would do- I have read from 7 to 20 ICE HP are used to operate the air conditioning system in a car. Adapt the electric clutch on/off to trigger a relay to the motor. Charge the system back up and done. Even simpler if your traction motor has dual shafts- use the CE to drive a pulley and drive the compressor that way. Only downside is that at long traffic stops the air is gonna warm up. 

Any way you look at using a compressor it becomes an energy issue. Do the math and even a small 5500 BTU window air conditioner uses about 500 watts of power at 115VAC with a starting load of about 3-4x that. Sure that’s just a moment or so at that load but one to be reckoned with if it is cycling on and off as the compressor is going to do at a set temperature. So that’s an added 1/2 KW of power to figure in to demand on the battery pack at a bare minimum. And personally I doubt 5500 BTUs would adequately cool a small car in the Arizona heat- a delta shift of about 22 degrees with a relatively small CFM output just aint gonna cut it for most folks sitting in a un-insulated car in the 110 degree heat.

So a low power air conditoning system is a path that most EV'ers would want to consider. Even if it is a rather elusive one. Just my random thoughts on a rather soggy June day.


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## dogshed (Dec 25, 2009)

Due to idling laws self contained power units with heat and AC are being used on big rigs. Unfortunately some areas have passed laws that ban the running of the little diesel power units, so there are some companies making systems that run the AC and heat off of batteries.


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## Tommahawk (Sep 28, 2008)

Go thermo-electric, efficient in heating and when you require cooling guess what its hot outside solar can be effective. They are small as well, you total air con system would comprise the size of a computer psu hint. Point to make you won't be won over on peltiers unless you have a thermal and volt/amps overload circuit to protect the peltier from getting fried.

The unit will probably freeze a container of water or a gel pack then turn off where fans with decent cfm will blow cold air in and pump hot air out. Reverse the polarity and you get heat, reverse it again you get cooling.

I don't have a unit and don't know if anyone makes them.

traditional air-cons are big and heavy and use gas which should not be welcome in your ev.

Just my two scents worth.


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## TX_Dj (Jul 25, 2008)

Tommahawk said:


> Go thermo-electric, efficient in heating and when you require cooling guess what its hot outside solar can be effective. They are small as well, you total air con system would comprise the size of a computer psu hint. Point to make you won't be won over on peltiers unless you have a thermal and volt/amps overload circuit to protect the peltier from getting fried.
> 
> The unit will probably freeze a container of water or a gel pack then turn off where fans with decent cfm will blow cold air in and pump hot air out. Reverse the polarity and you get heat, reverse it again you get cooling.
> 
> ...


I don't see how AC in an EV requires gas... there are many who do it, none use gas. Most will either retain the stock compressor and either drive it from the traction motor tailshaft or via a separate motor entirely, others have units which are essentially converted from window-unit ACs which are compact and fit into the original radiator opening.

Further, thermoelectric devices like the peltier setup are extremely (i mean EXTREMELY) inefficient... about 5%. OTOH, the setup with a separate motor that drives the stock compressor is about 90% efficient (at least in turning the compressor, uncertain of actual cooling system efficiency, but I'll bet a dollar it's better than 5%).


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## belair (May 24, 2010)

I am going to TRY to use a 130V DC treadmill motor rated at 2.8 continuous at 100V off my 96V pack to power the stock AC, a new vacuum pump from a Rover, and the stock power steering pump. The vacuum and power steering are fractional hp requirements but the AC may be as much as 4hp from my best info. The motor, a new Nordic track unit, is small and 10lbs without the 5lb flywheel. It was $100 off ebay but I have doubts that it will get it done. If not I may be on to bigger DC motors and perhaps a shunt golf car motor. The little one is rated as a 1500watt draw so about 500W for a normal 20 minute 10 mile drive.
If I get 300W/mile off the AC50 thats 3500W for the trip without sweat. I will let you know in a couple of months.


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## TX_Dj (Jul 25, 2008)

belair said:


> 130V DC treadmill motor rated at 2.8 continuous at 100V off my 96V pack to power the stock AC


At the rated voltage and continuous current, that's just under half a horsepower not counting efficiency losses.

You'll need about 30A at 96v to get near the 4HP figure you're speculating.


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## greenevegiebeast (Jun 28, 2010)

This is one ov the main issues, I'm very concerned with. The typical "automotive" type A/C system can use as much as 5hp, depending on ambient temp, system efficiency, maintains exc.... when you factor in that here in south central TX we run the ac the whole time you are in the vehicle(we have 2 seasons, summer and almost summer) even if you do a short commute thought low speed traffic it would drastically reduce your range.

now that Ive said that, some of the newer cars a shifting over to more electric component's in an effort to gain efficiency. I'm not sure if the still make it but i do believe "Vintage Air" has a kit with an electric (DC) powered compressor. if you have to have A/C due to the engineering and fluid dynamics involved i would recommend a kit over piecing it to gather yourself. if you do convert a IC(car type) be sure to get a variable displacement type compressor and all the matching components. GM has one of the better designs i have seen. the variable displacement compressors are much more efficient than the older rotary or position compressors. 

My thought on that was remove the clutch(electro magnet... aka energy hog) and directly connect a motor to the input shaft of the compressor. use a relay linked to the pressure cut out switch for the cycling. the factory relay is only rated at 30amp peek. a motor strong enough to turn the compressor under pressure at start would need more than that. you would fry the factory relay in seconds.

On an additional note , if you are not worried about it R12 is a more efficient refrigerant, that work's under lower pressure than R134a. though now due to EPA regs, you have to have a license to even purchase it, and it is expensive.


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## belair (May 24, 2010)

Again for clarification I do NOT feel that the 2.8hp motor will be enough but hopeful. It will be fantastic if it works as it is a slick little lightweight unit with a built in fan. Pics to follow.


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## TX_Dj (Jul 25, 2008)

I can't find the info now, but one of our local NTEAA members has a unit that was factory designed as an EV AC unit, the type I mentioned which uses typical window AC unit parts and fits in the location of the stock radiator. He's been enjoying cool air, and it doesn't detract much from his 40+ mile range. Well worth investigating, I sure wish I remember where he got it.


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## JRP3 (Mar 7, 2008)

Did it look like this? http://www.electricbluemotors.com/coolblue.html


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## Tommahawk (Sep 28, 2008)

As of me I don't mind the heat, its the cold that freaks me out. Check this out, its thermoelectric based and 8 by 6 inches complete. That will cool the car no probs and no compressors pipes, refridgerents, no extra weight, no moving parts etc. that will do the trick

http://www.eicsolutions.com/200btu-thermoelectric-air-conditioner.php

job done!!!


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## 9852 (Jan 17, 2010)

Tommahawk said:


> As of me I don't mind the heat, its the cold that freaks me out. Check this out, its thermoelectric based and 8 by 6 inches complete. That will cool the car no probs and no compressors pipes, refridgerents, no extra weight, no moving parts etc. that will do the trick
> 
> http://www.eicsolutions.com/200btu-thermoelectric-air-conditioner.php
> 
> job done!!!


I found that website today, i think they are cool, I will be calling for pricing tomarrow, and may be ordering one or two just to see how well they work.


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## magudaman (Mar 29, 2009)

The problem with thermoelectric is they are quite poor heat pumps when compared to a compressors. 

Thermo electric = 600BTU at 219w = 2.73 btu/w

Compressor R134a = 15,461 BTU at 1900w = 8.14 btu/w



Compressors are around 3x more efficient just from those quick numbers. That is comparing a TECA thermo electric unit to a master flux unit. And the masterflux units don't seem to be that great either since I've seen my window ac unit get around 10 btu/w 

If your interested in building your own thermo-electric ac unit, the modules are always up on ebay and they are fairly cheap. I built a mini ac unit a long time ago using a computer heat sink and fan on one side and a water cooling block from a PC on the hot side that ran to a small radiator. 

One of the bigger modules: http://cgi.ebay.com/Gigantic-62mm-5...itu=UCC&otn=5&ps=63&clkid=7484340904964900186

The other issue is you really need more BTUs to cool a car. Most cars are some where between 10k to 50k BTU. I think I had seen a Acura Integra according to the service manual is 14.2k BTU


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## Tommahawk (Sep 28, 2008)

http://www.eicsolutions.com/400btu-dc-thermoelectric-air-conditioner.php

They have higher BTU units

Their are other factors...

such as weight (efficiency) of a typical automobile a/c that you are carrying all the time even when not using air con.

such as the size of a typical automobile a/c (the space could be put to better use)

such as the freon gas that is introduced into an emission free car and is ozone layer depleting when (don't be naive) finally ends up being released into the atmosphere.

and lastly realistically usage of a/c in a standard car perhaps no more than 100 hours a year so why the fuss with efficiency. The think the lower efficiency is more than made up

I think eicsolutions.com is a decent answer.


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## few2many (Jun 23, 2009)

Ok, so, a typical automotive air conditioning can range from 1-3 tons, thats 12,000 to 36,000 btu's of heat absorbtion. The largest I see from eic solutions is only 2,500 btu. Any larger and they go to traditional compressor based systems for a reason. Imagine trying to fit 10 of these units in an ev, not to mention trying to power them and still barely getting enough to cool!
Also, a while ago, I recall seeing a tv program about a money saving home and commercial ac system on one of the alt/green energy shows. It was a production unit. It wasnt highly efficient, had about the same efficiency of normal ac. It ran at night when temps were cooler and the power was cheaper. What it did was freeze a large insulated container full of water into a huge block of ice during the night. This block of ice had alot of glycol lines running through it which were used to cool the home during the day.
I've have also seen little picnic coolers full of ice water with recirculating pumps and fans on a small heat exchanger like an oil cooler.
Why not have the container of water in the ev, freeze it over night using a home power outlet while charging, and circulate glycol through the heater core to cool?
Or just get a 3/4-1hp, 115v off the shelf compressor and run it off a 2500 watt inverter and keep the rest of the system traditional. Even the cheap harbour freight inverter i have can run one!
Really, how long does an ev ac need to run, as long as the range!


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## few2many (Jun 23, 2009)

Tommahawk said:


> http://www.eicsolutions.com/400btu-dc-thermoelectric-air-conditioner.php
> 
> They have higher BTU units
> 
> ...


The higher btu units start using traditional compressors.
The weight factor, all aluminum and plastic.
The size? Mostly hidden under the dash, with the little compressor under the hood and the condenser hidden in the grill
The newer refrigerants(freon is a brand name) are much more environmentally safer. Give it time, they will find what the new stuff is damaging or doing harm to!
On the last point, I agree with you. I live in Arizona and would use ac on full blast 3-4 months out of the year. Heat for 3-4 months and roll the windows down in between.
It is a nicety, a comfort option that has its costs, whichever route you take.
On a side note: Has anyone noticed that all the original Dupont freons are becomeing illegal for production or use, right around the time that the patents are up and any company could start making them? Now Dupont has these revolutionary new safe refrigerants, and the patents on them too!
Dupont is responsible for the global warming hoax!
Kidding, kind of, thats just the conspiracy theorist in me coming out to play.
Wow I'm bored.
Has anyone even read this far?


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## JRP3 (Mar 7, 2008)

I'm going to try wrapping freezer gel packs around my heater tank with some insulation and see how that works  Should be able to pump some cold water through my heater core for a while, though condensation may be a problem.


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## 9852 (Jan 17, 2010)

yep, I read it, I live in phoenix as well, and the heat is high right now, but Im not talking cooling the car down to 60 degrees when it is 150 degrees inside the car after work. I would like to just cool it enough to be out side temp. i know that TECs are not efficient, but if it woukd do the job that I want great, if not well I will continue to roll down the window, but I was thinking the 2 of the 400 w units, on the back dash just might do the trick, and if not my computer could use some better cooling.


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## TX_Dj (Jul 25, 2008)

JRP3 said:


> Did it look like this? http://www.electricbluemotors.com/coolblue.html


That's the one!

His works like a champ, even though I disagree with him charging it with R11 instead of R134A.


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## JRP3 (Mar 7, 2008)

TX_Dj said:


> That's the one!
> 
> His works like a champ, even though I disagree with him charging it with R11 instead of R134A.


As I commented earlier in the thread it looks to me as if they just took the components from a small window unit, which you could do a lot cheaper than what they are asking. To run theirs you still need to have custom hoses made up, charge the system, and get a 12VDC to 120VAC inverter.


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## 9852 (Jan 17, 2010)

here is an update on the thermoelectric air conditioners from EICsolutions, for the 200 BTU unit they want 800.00 bucks and that would still be to small to cool the inside of a geo metro in phoenix heat, for me I will try something like the cool blue system using a small window unit.


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## JRP3 (Mar 7, 2008)

That's the DIY spirit  I'll be interested to see how it works.


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## 9852 (Jan 17, 2010)

well, I only have one problem with using a window unit ac, and thats is that I dont know if I could use r134 with that compressor. but worst case Ill use the refergirent that it comes with.


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## JRP3 (Mar 7, 2008)

I've been wondering if the home A/C units refrigerant is compatible with the car components.


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## 9852 (Jan 17, 2010)

well, i was just researching that very thing, I think that the compressor does not know the difference, as long as you evacuate the system, a cars evaporator in the dash does not know the difference, so i think that you can use the home freon, with a unit like that, just have a fill valve made in the line, and use the ac components minus the evaporator, which you will replace with the one in the car's dash. Im going to give it a shot, both ways, I would rather use r134, but for me, its what ever works. I think you just need to keep the system pressure with in the cars ac limits.


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## JRP3 (Mar 7, 2008)

There might also be compatibility issues with lubricating oils, seals, and hoses, so you might want to check with an A/C pro to be sure.


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## 9852 (Jan 17, 2010)

yep, i just spoke to a friend who does HVAC and he said if im making the lines, I shouldent have a problum to use the r134 as long as i have a COMPLEATE evacuation done to it, to get out all of the oil and residual freon, then just change the seals to ones made for r134 and it will work, If I wanted to go that route, he looked at me kinda funny when i told him what i wanted to do with it. but he did not recommend using residential refregirant for the car, some thing about the pressure.


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## TX_Dj (Jul 25, 2008)

billhac said:


> yep, i just spoke to a friend who does HVAC and he said if im making the lines, I shouldent have a problum to use the r134 as long as i have a COMPLEATE evacuation done to it, to get out all of the oil and residual freon, then just change the seals to ones made for r134 and it will work, If I wanted to go that route, he looked at me kinda funny when i told him what i wanted to do with it. but he did not recommend using residential refregirant for the car, some thing about the pressure.


Yes, the pressures are a little different, and the point about the seals and hoses and proper evac is almost all that is required to convert an older R11 car to R134A. The other two parts that have to be changed are the orifice tube (this is the part that the compressor compresses the refrigerant against to create the cooling effect) and the high/low pressure valves (134 uses different valves to prevent contamination between system types).

134 is much more sensitive to fluid ratios (refrigerant to lubricant, any air in the system or contaminants) but doesn't have as bad of an environmental impact as 11. Plus, you can pretty much work on 134 yourself in most states, whereas you need a license and recovery equipment for 11 in all states.


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## 9852 (Jan 17, 2010)

I will be getting the unit tomarrow, and want to start a new thread about the air conditioning conversion, can i start a new thread or should I just post the process here?


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## TX_Dj (Jul 25, 2008)

billhac said:


> I will be getting the unit tomarrow, and want to start a new thread about the air conditioning conversion, can i start a new thread or should I just post the process here?


I would recommend discussion like this to take place in the forum, not the wiki. The wiki is a location for facts and information, not discussion.


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## few2many (Jun 23, 2009)

The most important thing to the conversion, when you start changing refrigerants, is the thermostatic expansion valve, or txv. This is the metering/restriction device that controls the flow of refrigerant into the evaporator. It is attached to the evap inlet and a sensing bulb on the outlet that controls it. It also prevents liquid from hitting the compressor, slugging the compressor and destroying the valves. They are set up for different pressures for different refrigerants and temperature ranges.
To get all the oil out of a system, you have to remove components, like the compressor and pour out the oils. Then, clean and flush. To do it right, is difficult and time consuming. Also, you need to make sure you have enough condenser heat rejection and evaporator heat absorbtion. its actually a carefully balanced system. Youre best bet, IMHO, is to reuse all the components, only changing the means for running the compressor. (belt, seperate motor, hemetically sealed electric) There are freon and oils that are compatible, and then there are some that will turn into a thick sludge and plug up the system.
Have fun experimenting!


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## Tommahawk (Sep 28, 2008)

easy just customize a $10 car beer cooler from ebay


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## 9852 (Jan 17, 2010)

Tommahawk said:


> easy just customize a $10 car beer cooler from ebay


 
did that, it works ok untill it gets over 100 then its no good.


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## greenevegiebeast (Jun 28, 2010)

EV-propulsion.com said:


> most home air conditioners (central or window) use r-22. As JRP said, R-134a replaced r-12 years ago as it was blamed to deplete the ozone layer and it was banned to manufacture it. If you were to use this unit, it would more than likely need r-22. (which btw, both r-22 and r-134a are planned to be replaced also with more envionmentally friendly gas, possibly CO2) Also by the way, you need a EPA license to purchase R-12, and technically a special class of the EPA license to fill this unit in a vehicle.
> Mike
> www.EV-propulsion.com


 
AS of a few years ago the EPA also regulates R22, we had to check EPA license to sell it to a customer.


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## PZigouras (Jun 5, 2010)

I just have a large ice/water tank that circulates through my A/C core using a regular winsheild washer fluid pump. It's not powerful, but it blows cool air for a few hours. 

I'll upload a photo of my fill hole (on the hood) -- you don't have to open the hood to add ice, just the ice fill door.


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## JRP3 (Mar 7, 2008)

Neat idea, are you at all concerned about corrosion of the A/C core? They weren't designed for water.


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## few2many (Jun 23, 2009)

JRP3 said:


> Neat idea, are you at all concerned about corrosion of the A/C core? They weren't designed for water.


 I think he means the heater core, or at least the heater core would be ideal. The a/c core probably couldnt flow enough water. 
I do like the heater core/cold water idea. Gives you a heater and a cooler, but then you have to heat and cool the same water somehow. There was a good idea somwhere.


JRP3 said:


> I'm going to try wrapping freezer gel packs around my heater tank with some insulation and see how that works  Should be able to pump some cold water through my heater core for a while, though condensation may be a problem.


 There it is, I like it!


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## JRP3 (Mar 7, 2008)

few2many said:


> I think he means the heater core, or at least the heater core would be ideal. The a/c core probably couldnt flow enough water.


I asked because I actually did that once in an old ICE. The heater core was bad and it was major surgery to get to it, and I didn't have a lot of cash. The A/C system had been removed so I just hooked the heater hoses to the A/C core. It worked well for a while, until that too went bad and started leaking.


> I do like the heater core/cold water idea. Gives you a heater and a cooler, but then you have to heat and cool the same water somehow. There was a good idea somwhere.
> 
> There it is, I like it!


I actually gave it a half hearted attempt the other day after a week of 90+ temps. It did give me a few minutes of cool air but not enough. Problem is I needed to wrap the tank, let it sit and cool down for a while, then put on fresh frozen gel packs when I was ready to drive. Plus probably should have wrapped insulation around it too. Instead I gave up and jumped in my ICE car and turned on the A/C.  Luckily we don't see 90 around here for more than a few days, normally.


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## PZigouras (Jun 5, 2010)

JRP3 said:


> Neat idea, are you at all concerned about corrosion of the A/C core? They weren't designed for water.


The core is aluminum, so yes, it will eventually rot out... but by then I would have already gone through three battery packs anyways.... 

and besides, after it starts leaking, I can always switch the hoses over to the heater core for as long as that lasts


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## Tommahawk (Sep 28, 2008)

Did anyone end up getting a price on the http://www.eicsolutions.com solid state a/c systems I tried to email them but no reply as yet.


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## BobS (Jul 12, 2010)

I have a couple of questions for you guys:

1. Do any of you know how much cooling power an air conditioning unit in puts out in a EPA rated mid-size car? 

2. Do any of you know how much power it takes to turn an automotive rotary A/C compressor versus a piston type?

Best regards,

Bob


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## 9852 (Jan 17, 2010)

Tommahawk said:


> Did anyone end up getting a price on the http://www.eicsolutions.com solid state a/c systems I tried to email them but no reply as yet.


 
yes, they are expensive, 700 for the 200btu unit


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## BobS (Jul 12, 2010)

I was asking the question to see if anyone really understood a/c power draw....

http://www.sanden.com/index.php?id=U5H0AMX7Q

With these charts, you can calculate the power draw from the load you are inputting to the a/c system.

Just like the OEMs do...


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## few2many (Jun 23, 2009)

BobS said:


> I have a couple of questions for you guys:
> 
> 1. Do any of you know how much cooling power an air conditioning unit in puts out in a EPA rated mid-size car?
> 
> ...


1. I've read 1-3 ton, but have no solid numbers.
2. Do you mean scroll vs piston?
power required to turn depends on load and engine speed.


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## rmay635703 (Oct 23, 2008)

I am reminded of what my father used to do by a recent full page newspaper ad touting the most efficient air conditioning.

Not sure if anyone else noticed this but they are actually selling boxes that you place a block of ice in that have a fan on top with ice on top, the air is forced over the block of ice and through a mesh that has the melt water on it. My father used to use a block of ice on really hot days coupled with a fan years ago, rather surprized someone is marketing it

But that said might be worth thinkin about, heck on hot days I take those large gel filled ice compresses we had from surgery and wrap them over my sholders.

Look outside the box, there are cheaper and oddly enough more effective ways of staying cool than wasting 50% of your range on AC.

That said I often wondered if the old edison, designs with no moving parts would work off of solar heat on your cars roof.

Cheers
Ryan


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## JRP3 (Mar 7, 2008)

Problem is those other methods don't lower humidity and can actually raise it which makes things more uncomfortable.


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## BobS (Jul 12, 2010)

JRP3 said:


> Problem is those other methods don't lower humidity and can actually raise it which makes things more uncomfortable.


 Not just more uncomfortable, but also, the higher humidity can penetrate the wiring and electronics (such as the radio....you all DO have tunes, right?) causing corrosion, shorts, and other nefarious and sundry issues (things like corroded door locks and latches, corroded power window motors, if equipped, etc.).

All in all, a really, REALLY bad idea for an automobile.


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## rmay635703 (Oct 23, 2008)

BobS said:


> Not just more uncomfortable, but also, the higher humidity can penetrate the wiring and electronics (such as the radio....you all DO have tunes, right?) causing corrosion, shorts, and other nefarious and sundry issues (things like corroded door locks and latches, corroded power window motors, if equipped, etc.).
> 
> All in all, a really, REALLY bad idea for an automobile.


Actually my car did not come with a radio, it was an optional component.

LoL nothing like being draconian, you do realize much of your engine compartment and everything in it gets wet during rain? 

You do realize the insides of your doors get wet each time it rains as that is where the rain is channeled through off the window?

Vehicles are designed to be moderately reliable in the presence of water because water is unavoidable in most areas of the car except the inner cabin and trunk.

I think you believe I was talking about putting a saltwater mist in the cabin, that would accomplish what you state. 

Also Door jams on cars are designed to get wet now and again and I have never seen one rust, I have seen the floors rust out but never a door jam, even on cars by the ocean mists out east. But then again the hinges on my 1970 subaru are a bit rusty but they are also on the outside of the car and the car is 40 years old. Nothing enough to cause a functional issue though.

Cheers


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## BobS (Jul 12, 2010)

rmay635703 said:


> Actually my car did not come with a radio, it was an optional component.
> 
> LoL nothing like being draconian, you do realize much of your engine compartment and everything in it gets wet during rain?
> 
> ...


Yes, I stated exactly what I meant-after over 30 years of designing vehicles (civilian and military) I have seen a "few" problems from moisture. There is a reason military electrical systems use Cannon plugs, and civilian vehicles use Weatherpac connectors.


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## RK_EV_hopeful (Jul 16, 2010)

mid size cars need about 14,000 btu/hr capacity to "pull down" the temperature in a reasonably short time. The unit at this link has about 10,000 btu/hr capacity. It's advantage is that full capacity is working even when the car engine is idling. So it might be enough.

http://www.alibaba.com/product-gs/219708723/Brushless_DC_Electric_Compressor_For_Vehicle.html

Still researching variable speed car ac scroll compressors.


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## 9852 (Jan 17, 2010)

RK_EV_hopeful said:


> mid size cars need about 14,000 btu/hr capacity to "pull down" the temperature in a reasonably short time. The unit at this link has about 10,000 btu/hr capacity. It's advantage is that full capacity is working even when the car engine is idling. So it might be enough.
> 
> http://www.alibaba.com/product-gs/219708723/Brushless_DC_Electric_Compressor_For_Vehicle.html
> 
> Still researching variable speed car ac scroll compressors.


 
that looks good but at alibabba, they require an order of 40 or more, so though they have some good things, It dont work for do it yourselfers.


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## few2many (Jun 23, 2009)

Every 12,000 btu's is one ton. 
I think an ac scroll compressor is the way to go, but to get the variable speed compressor requires an inverter similar to, but much cheaper than an ac traction motor inverter. It takes normal household 220, turns to dc, then inverts to 3 phase. Also, you need the controls for the inverter to run at the correct speed.


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## RK_EV_hopeful (Jul 16, 2010)

Here is another source for the compressor, variable speed controller and accessories:

http://www.revoltevc.com/climate/cooling.html?limit=all


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## few2many (Jun 23, 2009)

$500 for compressor, $300-$500 for speed controller, Labor and parts to fit into an oem system. Nice for the guys who can afford it. Not for me


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## dogshed (Dec 25, 2009)

Someone mentioned ice. What about dry ice?
Ammonia?


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## JRoque (Mar 9, 2010)

Hi. From what I've seen, some of the AC solutions for EVs include a 120V AC compressor that requires an inverter to run off DC. There are others that run off 12/24V like AC units for boats, etc. These solutions start at about $500 and run to $1500. You're left with the task of integrating these to the rest of your car's AC system.

Its always hot here where I live so AC running always is a must. My donor car has an excellent AC system that would just require a pulley off the main electric motor. The issue with this is that I would have to "idle" the motor always. But if AC is a must and there are other things like power steering and maybe a water pump that must run as well, doesn't it make sense to tap the main motor and run these like they do in the ICE? The alternative of two or three smaller electric motors with DC-DC converters and speed controls seems costly for little efficiency gains.

I'm glad we're all talking about this now during the (northern hemisphere) summer. I'm sure that by October you will all forget about this and jump on "heating" topics :- )

JR


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## stevejamaican (Oct 27, 2010)

Here is a link that explains how to build a thermo-electric air conditioning solution. The article also has a video that explains the whole thing. http://hubpages.com/hub/How-to-Make-an-Air-Conditioner-from-Peltier-Modules

Here is another resource that outlines some EV air conditioning options, including a compact compressor from a company called Masterflux: http://www.suite101.com/content/peltier-modules--air-conditioning-for-electric-cars-a238651


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## magudaman (Mar 29, 2009)

magudaman said:


> The problem with thermoelectric is they are quite poor heat pumps when compared to a compressors.
> 
> Thermo electric = 600BTU at 219w = 2.73 btu/w
> 
> ...



Well I know this is an old thread but I couldn't take my own advice about the thermo electric systems and had to try it out. I figured I would reawaken everyone to show you what I put together.

So my fiancee is still driving an old Hyundia around in our 105F heat with no AC and I wanted to create something that runs off the standard alternator that would take the edge off during these summer months.

What I have ended up with so far is a 50mm by 50mm thermoelectric module that has a peak pumping capacity of around 800BTU while consuming around 24 amps at 14.4v. From what I am reading thought the pumping capacity drops when there is a greater temperature difference two sides of the unit so really I'm only getting 500BTUs or so maybe even less :-(











I created a water block on the CNC mill and tied together with a copper computer heat sink that will blow the cool air toward the driver.


















Below you can see I was anticipating it pulling moisture out of the air so I created a drip tray for the water to run into a container. The inlet and outlet differential isn’t large enough to create enough condensation that it actually drip down at all.





































I also have a 100+gph water pump that keep water moving through my radiator to be mounted in front of the engine radiator. It measures 5 inches x 11in and should have a peak capacity of around 700w with good air flow.


TESTING:

So other day I finally put all these parts together and got the whole system running and the numbers are promising but I really don't know if I will complete the install to the vehicle as I’m not sure if it will really help more than just a fan.

My power supply could only hold around 13.5 volts so the the thermo module is only running at around ~20 amps while my pumps and fans consumed another ~2 amps. 

My blower for the cool side pushes about 30CFM and with 90F inlet temp I was reading an outlet temp of 75.2F. This felt noticeably cool on the hand. 

My radiator outside was taking in 96.5F air and outputting 115F air. I was using a household box fan taped off to push air through but wasn't really flowing that good. I need to get some good high flow 120mm fans to move air over the radiator for testing but haven't picked them up yet and I think they would give better above numbers if I did.

Of course in a car you would have decent air flowing over the radiator when you are moving. I don't think I can leave computer fans on the radiator on the car as I would image that would over speed on the freeway?


So there you have it. I could go one more size up on the device to around 30 amps at 14.4v but doesn't gain me too much BTUs or if I could some how get 24v I can go up to a 800BTU (1300BTU max) but then the alternator will not be able to keep up.


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## JRP3 (Mar 7, 2008)

Nice work but I think you should have taken your own advice  Even if you get 800 btus it won't do much at all. I'd think you need at least a couple thousand, probably more.


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## magudaman (Mar 29, 2009)

JRP3 said:


> Nice work but I think you should have taken your own advice  Even if you get 800 btus it won't do much at all. I'd think you need at least a couple thousand, probably more.



Agreed, it was for the sake of a new project for my self more than anything, had some fun making it, but numbers rarely lie. I was now thinking about using it as a water chiller (multistage TEC) for a bomb 12v refrigerator / cooler that would use a micro controller for to keep the temps at 34F, maybe use glycol in my water then to allow for sub freezing circulation! The micro controller could even control a reverse on the TEC to do a little bit of heating to defrost the coils.


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## jeremyjs (Sep 22, 2010)

Don't TEC's have horrible efficiency? I would think sizing it up to something that would move as much heat as a typical car heat pump would take several thousand watts.


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## magudaman (Mar 29, 2009)

jeremyjs said:


> Don't TEC's have horrible efficiency? I would think sizing it up to something that would move as much heat as a typical car heat pump would take several thousand watts.


Yep very very true! For the same BTUs you would at least 3x more watts if not more. I'm not sure if your reply was directed at me but I wasn't planing on sizing it up at all. I did say multistage TEC for my cooler idea but that only would decrease my BTU and increase my temperature difference on the plates. That was just for cooling something like an ice chest or so. They look like this:


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## few2many (Jun 23, 2009)

Heres one for ya. I'm using it for a keggerator project. Its a 24 volt, 13amp thermo electric cooler. Pictured is the hot side and the cool side has one fan under. The power supply is the one to the left. Its a basic switching power supply to convert 120v to 24v.


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## etischer (Jun 16, 2008)

Here is a link to my Air Conditioning install write up. I used the MasterFlux Sierra compressor. At 2kw it is rated 19,000 BTU/hr. 

http://etischer.com/awdev/aircon.html


In the pic above, it would be kinda cool to mount the thermo-electric cooler directly to the keg rather than cooling the air around it. You could cool your keg much quicker, and probably get it colder.


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## magudaman (Mar 29, 2009)

etischer said:


> Here is a link to my Air Conditioning install write up. I used the MasterFlux Sierra compressor. At 2kw it is rated 19,000 BTU/hr.
> 
> http://etischer.com/awdev/aircon.html
> 
> ...



Read through your post a while back but realized I never responded here. Very nice setup, thanks for taking the time to put all the photos and information up. I was always interested in the masterflux setups and their site leaves a lot to be desired. Look like your in the area too! You blog on your car is a huge wealth of info!


Just FYI I am selling off my thermoelectric setup if anyone was interested in experimenting with it. I'm selling it complete with the radiator (w/ 2x 200cfm fans, pump, water block, copper cooler, tubing, all mounting and my reservoir. I'm running out of cash to keep other projects alive. I try and make a post in the classified section soon too.


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## Telco (Jun 28, 2008)

etischer said:


> Here is a link to my Air Conditioning install write up. I used the MasterFlux Sierra compressor. At 2kw it is rated 19,000 BTU/hr.
> 
> http://etischer.com/awdev/aircon.html.


Hello, how well did this system wind up working? And, is it possible that a smaller compressor like a 6000BTU compressor might work? I'm looking at doing a full size regular cab pickup electric AC conversion. Thanks.


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## etischer (Jun 16, 2008)

I haven't used it much in the last few months since it is winter here, but in the summer it worked well. It is slightly under powered compared to an I.C.E powered A/C. On the 100 degree days, I usually run it at full speed and it takes about 15-30 mins to get the car cool. I would not recommend going smaller unless you really need the inch or two space savings. 

The compressor I'm using is already very small. By the time you add fittings and hoses, the difference in size for the smaller compressor will be negligible. 










I'd recommend flushing the system and replacing the drier with a new one. 




Telco said:


> Hello, how well did this system wind up working? And, is it possible that a smaller compressor like a 6000BTU compressor might work? I'm looking at doing a full size regular cab pickup electric AC conversion. Thanks.


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## Telco (Jun 28, 2008)

I see. I was more concerned with electrical usage than physical size. This will have to be powered by my ICE alternator. While I may do a conversion one day, right now I'm more interested in increasing the efficiency of what I have as well as moving some weight from the front of my truck to the rear.

Question, assuming that this is on an EV converted car, did you install an electric fan to pull across the condenser? If not this may be part of why you aren't getting cool enough. Even on an ICE car with the factory system, the car must be going 45MPH or so to generate enough airflow to not need a fan on the condenser. Also, a variable orifice may help your performance. They cost a bit more than a regular orifice valve, but will automatically adjust to give you the best cooling performance. I used one on my 87 S15 pickup when I converted it to R134a, and it seemed to give me performance at least as good as the R12 did. Third, a parallel flow condenser may help. A parallel flow condenser is supposed to be able to reject heat as well as a condenser about 30 percent larger than the regular one it replaces. Thanks for the info though, I see a lot of folks talking about this, but few who actually do and of the ones that do few report their results.


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## etischer (Jun 16, 2008)

The condenser has an electric fan, but no longer has a belt driven fan. The electric fan is two speeds. It runs at low speed whenever the compressor is running and at high pressure it kicks into high speed, this only happens when parked for more than a few minutes with the compressor at 100%. The compressor can be throttled back to run at reduced power. 

You will be much better off with a belt driven compressor, the ICE has horsepower to spare and it would be a direct mechanical flow of power to the AC compressor. An alternator won't supply enough power to run the AC compressor, especially with the engine at idle. My compressor is 2kw and is barely adequate. It's not a matter of air flow though the condenser, it's a horsepower limitation of the compressor. 





Telco said:


> I see. I was more concerned with electrical usage than physical size. This will have to be powered by my ICE alternator. While I may do a conversion one day, right now I'm more interested in increasing the efficiency of what I have as well as moving some weight from the front of my truck to the rear.
> 
> Question, assuming that this is on an EV converted car, did you install an electric fan to pull across the condenser? If not this may be part of why you aren't getting cool enough. Also, a variable orifice may help your performance. They cost a bit more than a regular orifice valve, but will automatically adjust to give you the best cooling performance. I used one on my 87 S15 pickup when I converted it to R134a, and it seemed to give me performance at least as good as the R12 did. Third, a parallel flow condenser may help. A parallel flow condenser is supposed to be able to reject heat as well as a condenser about 30 percent larger than the regular one it replaces. Thanks for the info though, I see a lot of folks talking about this, but few who actually do and of the ones that do few report their results.


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## Telco (Jun 28, 2008)

Yeah, I realize the engine's got power to spare, but I'm hoping to get away from it eventually. If I make a conversion to full EV I want to make sure that everything currently driven by the engine has been removed beforehand. Thanks for the information on your setup though, it was most helpful.


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## r0n_d0n (May 12, 2012)

Has anyone tried an ammonia system, like old RV refrigerators and commercial cooling systems use? The system has to be in a secure spot with a weak point (a fuse of sorts) that would allow the ammonia to dissipate away from any passengers in case of a wreck or other failures. I was thinking it could be built into the battery container to keep it secure while keeping the batteries cool. And all it takes is a bit of heat to make it work. I am a newb here and this is my first post And while I am learning much about battery systems to fine tune my electric golf cart, I had to put my 2 cents in on an angle that may have been overlooked.


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## Wild (Aug 19, 2011)

r0n_d0n said:


> Has anyone tried an ammonia system, like old RV refrigerators and commercial cooling systems use? The system has to be in a secure spot with a weak point (a fuse of sorts) that would allow the ammonia to dissipate away from any passengers in case of a wreck or other failures. I was thinking it could be built into the battery container to keep it secure while keeping the batteries cool. And all it takes is a bit of heat to make it work. I am a newb here and this is my first post And while I am learning much about battery systems to fine tune my electric golf cart, I had to put my 2 cents in on an angle that may have been overlooked.


Due to the highly toxic nature of ammonia and the potential danger to vehicle passengers and any unsuspecting emergency response personnel not to mention potential lawsuits this type of refrigeration should never be used.


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## r0n_d0n (May 12, 2012)

Wild said:


> Due to the highly toxic nature of ammonia and the potential danger to vehicle passengers and any unsuspecting emergency response personnel not to mention potential lawsuits this type of refrigeration should never be used.


I wouldn't recommend anyone just try to make one, and if a pro was to make one he would install a leech line away from any potential passengers and build it inside a sturdy cage that was fabbed or ideally around existing framework. 

The gas is quite deadly, but I wouldn't think any emergency personnel would be in any danger in the event of a crash just like if they responded to me after stabbing an aerosol can with a knife. It's under high pressure, and would evacuate in seconds.

There is a refrigerant that resembles ammonia's properties, if I'm not mistaken, that takes very little energy to produce extreme cold. I'd have to do a bit of digging, and right now I'm mutteling through calculations and specs for my own selfish needs. 

I guess I should have added, "Don't try this at home kids."


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## Wild (Aug 19, 2011)

r0n_d0n said:


> I wouldn't recommend anyone just try to make one, and if a pro was to make one he would install a leech line away from any potential passengers and build it inside a sturdy cage that was fabbed or ideally around existing framework.
> 
> The gas is quite deadly, but I wouldn't think any emergency personnel would be in any danger in the event of a crash just like if they responded to me after stabbing an aerosol can with a knife. It's under high pressure, and would evacuate in seconds.
> 
> ...


Still there are too many variables to consider ammonia safe to use in a vehicle not to mention that said deadly gas is toxic in the PPM range. 
Oh yes let's not forget the fire - explosion risk...


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## Roderick (Dec 8, 2013)

I know this is an old thread but I've recently realised that I do want AC in my car after all

As for heating, Ceramic element replacement is most efficient but for cooling, is there any update with the technology for us without dual shaft method?


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## JRoque (Mar 9, 2010)

Hey Roderick,

These days there are several OEMs electric units that are available for cooling and heating. I would hunt for a recent model, crashed Nissan Leaf and have the entire system transplanted. The Leaf can keep you cool while using only 250 to 500W. Their heatpump is also the most efficient way to heat the cabin. 

JR


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## Sky (Jul 10, 2016)

I haven't seen much of this mentioned here but something that helps with keeping a car cool is the color (white, silver) and insulating the doors and floor. Also window tinting helps alot, they have some available with very light tint that still reflects infrared rays. Just some easy/cost effective things i would do to help reduce heat before installing an ac unit.


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## Moltenmetal (Mar 20, 2014)

Thermionic coolers are very inefficient, which is why the more complicated mechanical refrigerator is used for all but the smallest cooling loads, i.e. something like a beer cooler.


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## skeyes (Dec 3, 2016)

JRoque said:


> Hey Roderick,
> 
> These days there are several OEMs electric units that are available for cooling and heating. I would hunt for a recent model, crashed Nissan Leaf and have the entire system transplanted. The Leaf can keep you cool while using only 250 to 500W. Their heatpump is also the most efficient way to heat the cabin.
> 
> JR


Alright, so I am interested in doing this in 2017.... I know the Leaf, Prius, and some others have electric A/C compressors. It should be a simple matter to replace the OEM compressor on the donor vehicle with a Leaf compressor for instance, and add some custom A/C lines so that the adapter fittings work. However the thing that worries me is the controller... I can't seem to find out how much of the electronics would need to be reacquired out of a wrecked Leaf to get the A/C compressor to work. Seems that a lot of these fancy electric A/C compressors will require quite a bit more than an on/off switch to get them functional...

If anyone has a real world example of how they have pulled this off... I would love to know... Example: 
- I bought the used compressor from a [Leaf]
- I also bought this _____ module from a [Leaf]
- I spliced this _____ wire harness from a [Leaf] to my vehicle
and bada-bing bada-boom I have A/C 

Thanks!


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## arber333 (Dec 13, 2010)

skeyes said:


> Alright, so I am interested in doing this in 2017.... I know the Leaf, Prius, and some others have electric A/C compressors. It should be a simple matter to replace the OEM compressor on the donor vehicle with a Leaf compressor for instance, and add some custom A/C lines so that the adapter fittings work. However the thing that worries me is the controller... I can't seem to find out how much of the electronics would need to be reacquired out of a wrecked Leaf to get the A/C compressor to work. Seems that a lot of these fancy electric A/C compressors will require quite a bit more than an on/off switch to get them functional...
> 
> If anyone has a real world example of how they have pulled this off... I would love to know... Example:
> - I bought the used compressor from a [Leaf]
> ...


I have Leaf AC compressor and tubing at home. 
I havent resolved the interface problem though. It is supposed to be UART protocol but i cant replicate it with my comp. 
Does anyone have a scope with ability to decode protocols from signal? I would need TX signal bits from compressor turn on up to 3000rpm steady. 
I would use compressor on manual load. No fancy regulation...

anyone?


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## Watt Neon (Jul 23, 2017)

OK so the issue of turning on the compressor is daunting on a can bus level. But why are we stuck in controlling it that way. At some level this is an electric compressor and if the motor is powered it will compress. Can't we just break it open and go to the motor itself? 

Sent from my SM-N910V using Tapatalk


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## JeffAU (Jul 30, 2020)

Another system that I’ve thought of recently is recently is regenerative AC. Would be particularly useful for cars that don’t have regen braking, don’t know how much reduction it causes in regen efficiency on cars that do though. Basically a compressor that is coupled into the drivetrain, driven by the wheels when brakes are applied and some kind of thermal storage for when you’re not braking. It could also kick in from time to time when you’re not needing a lot of power as it needs to.


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## JRP3 (Mar 7, 2008)

Most EV's have regen, and the miniscule time you spend actually applying the brakes would not provide much energy to run an A/C compressor.


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## JeffAU (Jul 30, 2020)

Yeah that would likely be the case, I guess having a conventional type AC belt driven from the motor that decouples from the motor on heavy acceleration might work but not as efficient.

I might look at going down the path of the icebox idea mentioned earlier in this post and expand on it. My thoughts are to buy or build a small freezer that fits under the bonnet where the ICE (international combustion engine type) used to be, where there is space left by the smaller electric motor. Upgrade internal lining insulation if necessary. Put bottles or tubes of water inside freezer, run air tubes through freezer that connect to internal air vents. The freezer is powered through the charging input only and freezes the water then, the frozen water cools the car when on the road. Basically replacing ICE with ice but neither are the type that are going to get the attention of the police.

Might not work for quick charging though.


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