12volt compressor systems

[Kdj]

Newbi here,
Looking to modify a early 80’s aftermarket system
to modern components. Looking for opinion of 12v compressor systems. Packaging is the one advantage I see, and possibly being able to run without engine if battery are sized correctly. Installation would be in a camper van? Any input is appreciated.

[tbirdtbird]

12V comp will exhaust the capability of your battery and electrical system.
There are no Teslas on the road in the summer daytime heat in Arizona

[Cusser]

There are no Teslas on the road in the summer daytime heat in Arizona

I'm in Arizona, and there are quite a few Teslas on the roads here, even in summer. I know 3 Tesla owners and each says the AC works fine. And one friend owns an electric Mustang, says fine.

12V comp will exhaust the capability of your battery and electrical system.

I don't doubt this for gasoline & diesel vehicles running 12 volt alternators.

[Kdj]

Let me offer more information. I’m planning to install air conditioning in a VW Westfalia that never had a/c. I’ve read the excellent thread posted by vanis, and the hummer install. I’m planning to use a modified version of this installation.

IMG_4098.jpeg (47.34 KiB) Viewed 1173 times

With modern equipment inside and out. The reason I ask about 12volt is two fold. As the unit is toward the front already it seems hoses could be much shorter if compressor was under the floor. The option of being able to cool while parked is nice but I do understand the power requirements. Primary goal is cooling while driving though. And load on an already under powered engine. I currently have a 120amp alternator, and 200 ah of house batteries which should be enough to power while driving! Really just want to know if the technology of these is reliable or would it be better to go tried and true. I’m sure I’ll have many other challenges with is project. I will continue to educate myself on what it will take to get this done and appreciate this forum.

[tbirdtbird]

Your issue with a westfalia has come up before on this forum, but I don’t recall anyone posting results. This could merely be because many posters never give feedback unfortunately. Or because their project/approach /methods did not work. Do a search here. I am not understanding the concern with long lines…those hose diameter must be increased to a 10 or a 12 depending on what the size typically is. The are many applications with long lines. Trucks, buses, etc. suction line must be insulated of course. Many ppl are not even aware that a size 12 exists.

Cusser I respect your experience and contributions here. My comment about no sight of Teslas in the middle of the day in AZ and NV is sourced from a similar comment by the venerable poster by the name of Bohica [Brad] 2 years ago.

[Cusser]

Cusser I respect your experience and contributions here. My comment about no sight of Teslas in the middle of the day in AZ and NV is sourced from a similar comment by the venerable poster by the name of Bohica [Brad] 2 years ago.

I will admit that anyone parking ANY vehicle in the direct sun in summer in many states will find it takes a while to cool the vehicle, as the seats, dash, interior all get up to maybe 150F and that heat needs to be exchanged to get cooling. If under covered parking, even a 115F day/vehicle interior is way cooler than 150F !!!

Northeast Phoenix and north Scottsdale are full of Teslas, don't see any in the lower-income parts of the valley.....

[tbirdtbird]

Interesting. We don’t see that many here in Texas

[Tim]

Cusser I respect your experience and contributions here. My comment about no sight of Teslas in the middle of the day in AZ and NV is sourced from a similar comment by the venerable poster by the name of Bohica [Brad] 2 years ago.

I will admit that anyone parking ANY vehicle in the direct sun in summer in many states will find it takes a while to cool the vehicle, as the seats, dash, interior all get up to maybe 150F and that heat needs to be exchanged to get cooling. If under covered parking, even a 115F day/vehicle interior is way cooler than 150F !!!

Northeast Phoenix and north Scottsdale are full of Teslas, don't see any in the lower-income parts of the valley.....

And Prius doing 15mph next to the Suburau blocking all lanes of traffic.

[Scott Danforth]

You all know the Tesla compressor is 360 volts and pulls 13 amps. It runs off the mains. Not the auxiliary battery

[bohica2xo]

Yeah Scott, we know. My little hybrid Escape uses the same compressor. The good news is that it makes full output regardless of the engine speed. Even stopped.

I think the Teslas leave the road about 2pm, as they watch the 5kw going into the compressor kill their range - as they sit in traffic. Elon did a great thing digging a huge hole in the ground here. The Teslas run around in tunnels, shielded from the sun. They act as individual subway cars in a shared environment. A perfect use for them.

On to the "12v" compressor. In reality it is a 20cc scroll compressor with an internal 3 phase motor. Along with a small inverter to make it run.

I have installed one of these systems in the sleeper on a Peterbuilt. Customer bought it from the auction site we do not mention here. He bought the 24v model knowing it would need lots of power. Rated someplace between 12,000 and 13,500 btu / hour depending on who is selling it. Honestly 10k btu is probably more accurate.

Since the truck was 12v the plan was to start with a second 24v alternator on the engine I used a 110 amp 28v rated Delco 8600467. Also known as 8717N on the Lester interchange. That leaves enough current to run the unit AND recharge the battery bank. A pair of Group 31 12v 105 Ah batteries were installed on the frame and wired in series. The condenser and evaporator fans are 24v in the kit, so the stand alone 24v system was ready.

Install was pretty simple, the evaporator hung on the back wall inside, the condenser box and electric fan outside. It all went together fine for a chinese unit.

Run testing with the truck engine running was pretty good. You can drive the truck on the highway and cool the sleeper down quite well. Parking and shutting down the alternator is ok, but with a 40 amp draw you are asking a lot of the batteries. Resetting the thermostat higher helped some, but with an ambient temperature of 90f you get about 3 hours of cooling before the low voltage shutdown happens.

The owner has since added a second power source. The same auction site has small 24v generators with a single cylinder diesel engine. They look like a little cube, and seem to do just fine. Not really silent, but not as bad as a 15L Cat.

All I can say is it functions. 10k btu/h will cool a small camper. But there are a lot of little gotcha moments in the system design.

Trying to run a 12v system will mean 80 amps of current. 2 hours will hammer your house batteries in under 2 hours.