Converting Existing Vehicle Air Conditioning Compressor and Fan to Run via 110v AC

[JP FROG]

I live in SW Florida and the heat and humidity is off the chart during the summer months.  I would like to be able to run the vehicles air conditioning while hooked up to shore power.  I want to keep my 2006 Chevy Express as stealthy as possible and mounting an air conditioner in the back window or on the roof is not an option for me and the portable stand alone units will take up too much needed space inside.  It seems that if a vehicle's AC compressor could be disengaged from the engines drive belt and switched over to an electric motor (powered by shore power), you could have air conditioning without having to purchase and install a bulky separate unit.  Of course you would need to power the AC's circulating fan but it would be DC powered and could be run off the house batteries.  Has anyone run across any information on if or how this can be done?

 

[tx2sturgis]

I'll take the bait!

You mentioned stealth AND shorepower...but if you have a cord running to the nearest wall outlet its not very stealthy, and of course, neither is a running generator.

But, still, it's an interesting idea....

I see a few problems tho.

Aside from the mechanical complexity (which would be sizeable) you will need a motor of about 3-6 horsepower to run that compressor, and you need several amps of DC to run the dash blower, and you would also need an auxiliary electric pusher fan to blow air over the condenser unit in front of the radiator. Those also pull several amps, and they are not quiet!

You will also need some way to operate the electric or vacuum operated blend doors inside the dash, unless its an older vehicle that uses mechanical blend door linkages.

I think it would be much simpler to install a portable room AC unit with ducting to the floor or roof.

 

[user 423]

If you have an extended van you would have enough room to build a wall about 1' inside of the rear doors. You could then hang a room A/C on this wall. When hooked to shore power open the rear windows to vent the hot air from the A/C. Tint or curtains on the rear windows would make the A/C setup invisible from the outside to ensure stealth when driving around town or parked.

 

[Optimistic Paranoid]

As my brother is fond of telling me, "If you have access to a machine shop, a welder, and a big enough pile of money, you can build anything."  That said, I wouldn't think converting the engine a.c. to shore power would be either cheap or easy.  A 3 to 6 hp  motor is one honking BIG electric motor.

As a possible alternative, we had someone here who mounted a spare tire on the back door of his van.  He was able to conceal his air conditioner's exhaust behind it.  The a.c. sat on his floor, under his bed.

 

[tx2sturgis]

As my brother is fond of telling me, "If you have access to a machine shop, a welder, and a big enough pile of money, you can build anything."  That said, I wouldn't think converting the engine a.c. to shore power would be either cheap or easy.  A 3 to 6 hp  motor is one honking BIG electric motor.

Yep!

In the days before electronic engine controls, I can remember that when you kicked on the AC when idling, that big old honking 454 would idle down a bit from the compressor load.

We were always told back then that it takes about 5hp to run the compressor at highway speeds, and that is exactly why using the AC dropped your gas mileage.

Just a small amount of research here on the web reveals that the average SUV or sedan has an AC system that is in the 18,000 to 40,000 btu range, (that's about 1.5 to 3.5 tons) and it takes about 2 hp per ton of btu. More or less.

Most automotive AC units are sized for the hottest summer day in a place like Phoenix, with the car having 8 big non-tinted windows, it's been sitting on hot asphalt for 6 hours, the interior is 150 degrees, and the driver expects to get in, start the motor, and have the inside air cooled down in 5 minutes.

Not really the ideal candidate for running on an electric motor mounted under the hood.

But the reason I am interested in the idea is because I think there should be some way to build a small, stand-alone, efficient, gasoline engine powered AC unit.

Don't laugh....in the trucking industry we have a frame mounted APU (auxiliary power unit) that runs the auxiliary AC compressor directly off the small putt-putt diesel motor in the APU cabinet. I believe its around 9 hp but don't quote me on that. The alternator on that small diesel motor provides DC power for hotel loads and charging the batteries, as well as powering the condenser fan outside and the blower motor in the sleeper compartment.

Anyway. What if you could buy a very small 5000 btu AC unit that looked similar to a small inverter generator, but instead of electricity, this thing had a direct drive compressor powered by the small gas engine, and then it had all the parts needed to blow cold air....bypassing all the inefficiencies and cost of using 2 separate devices. It could be roof mounted or bumper mounted and have 2 hoses for ducting air inside the RV or van, trailer, whatever.

Not like that other kickstarter thing, this would keep blowing cold air as long as you kept gasoline in the tank.

Inverter generators are very efficient and very quiet...I imagine this little portable AC would be also.

All it would take is lots money to engineer, develop, and manufacture...

Maybe *I* should open a kickstarter project!

 

[user 15722]

Maybe *I* should open a kickstarter project!

Of course !
This might be a good start for a prime mover...

http://jsemei.en.made-in-china.com/...d-Single-Cylinder-Diesel-Engine-R175ANL-.html

Actually I was looking for one with a vertical crankshaft for a flatter profile to mount between the frame rails. No luck so far on that search.
wheels

 

[Optimistic Paranoid]

Most automotive AC units are sized for the hottest summer day in a place like Phoenix, with the car having 8 big non-tinted windows, it's been sitting on hot asphalt for 6 hours, the interior is 150 degrees, and the driver expects to get in, start the motor, and have the inside air cooled down in 5 minutes.

Years ago, when the Japanese were just starting to break into the American car market (Remember when Nissan was Datsun?) the Japanese design engineers couldn't BELIEVE the American obsession with air conditioning.

Then they'd come over here for a design conference, and the Americans would take them for a ride through Death Valley . . .

 

[sometimesido]

I'm interested in this topic.
I found this webpage and can't make a whole lot of sense, but maybe one of you can.

http://www.hotspotenergy.com/DC-air-conditioner/solar-AC-technology.php

 

[TMG51]

Does the A/C run with the key in the "on" position (not running)? Maybe the simplest solution is to turn the key on and use your 110v to maintain the engine battery?

 

[tx2sturgis]

Does the A/C run with the key in the "on" position (not running)? Maybe the simplest solution is to turn the key on and use your 110v to maintain the engine battery?

Well that would power the vent, but the AC requires the engine running to be turning the compressor...cuz that piece takes power from the engine.

 

[Optimistic Paranoid]

I'm interested in this topic.
I found this webpage and can't make a whole lot of sense, but maybe one of you can.

http://www.hotspotenergy.com/DC-air-conditioner/solar-AC-technology.php

Looks like it's designed for an off grid cabin.  Needs a minimum of 1,000 watts of panels.  Runs on 48 volt dc, so you need a 48 volt battery bank.  Costs $4,000.

 

[TMG51]

Well that would power the vent, but the AC requires the engine running to be turning the compressor...cuz that piece takes power from the engine.

Right, that makes sense.

 

[sometimesido]

Done some more digging and it still looks like the cheapest/easiest way to have ac in a van is small window unit with 950+ watt of panels and lots of batteries. There's got to be a better way.

edit: to run through the night. I know you can run it few hours on less setup.

 

[Trebor English]

Maybe a different approach could work.  Take the hermetically sealed motor compressor unit from an appropriately sized air conditioner and add that to the Chevy Express with some appropriate valves.  The normal automotive eletric fans could be used to blow through the evaprator and condenser.  Since big air conditioners run on 220 volt your shore power connection would need to be a 50 amp service To get 220.

It might be sufficient to put the two compressors in parallel with just a check valve to stop the reverse flow through the non-running compressor.  You probably would want an interlock so that only one compressor runs.

There are still lots of details.  Which refrigerant, over pressure relief valves, expansion valves?  Two expension valves, a different one for each compressor?

 

[steamjam1]

I've been wondering about the zero-breeze portable AC. Apparently it runs on 12V and is designed for up to 60sq-ft... Anyone try one? Apparently they work pretty good.

 

[tx2sturgis]

That's the kickstarter cooler I referred to.

I dunno if something that small will cool much more than your face right next to the vent opening...

Maybe it will...who knows?

 

[Sailing VANessa]

Check out the AC system in a Prius, or any electric car. They are electric.

 

[tx2sturgis]

Check out the AC system in a Prius, or any electric car.  They are electric.

But the power to run that AC comes from a BIG battery, and the power to charge that battery came from somewhere....either an on-board generator (in a hybrid) or at home or at a city parking lot with the charging station.

I agree the components might be able to be adapted...but still...way cheaper and easier to toss in a portable AC unit and make the rectangular hole in the door or drill a couple of 4" holes.

 

[Weight]

Lowe's has a 3 piece kit available. Plug and play. The vehicle adaptation is up to you.
https://www.lowes.com/pd/Utilitech-6-ft-50-Amp-6-Gauge-Black-Indoor-Extension-Cord/3165699
https://www.lowes.com/pd/Frigidaire-5000-BTU-150-sq-ft-115-Volt-Window-Air-Conditioner/50342322
https://www.lowes.com/pd/Champion-P...ter-Portable-Generator-with-Engine/1000039699

 

[JP FROG]

If you have an extended van you would have enough room to build a wall about 1' inside of the rear doors. You could then hang a room A/C on this wall. When hooked to shore power open the rear windows to vent the hot air from the A/C. Tint or curtains on the rear windows would make the A/C setup invisible from the outside to ensure stealth when driving around town or parked.

Great idea for those stops where power is available.