Collecting the parts...

[Fordguy64]

Well I'm going to venture into the world of engine driven ac systems. I've been collecting parts and I still have a few more to go. My plan is to build a tri-gen system for my house/garage. So far I have a z482 Kubota an ac compressor from an 06 mazda3(it was free)also  an old 3ton condenser coil with fan. I think I'm going to buy a brazed plate heat exchanger for the evap side to cool water. Although I do have a 2.5 evap and a large blower motor out of my parents house. So maybe I'll just hack that all together to play with first.. I need to find a pulley to put on the Kubota to drive the compressor..  I'll be posting picture soon

[glort]

I have wanted to do an engine driven AC for some time. 
Got all the parts from a Subaru and had them lying round for a couple of years till I recently moved and ditched them all.  No problem, I can get as many as I want.  New place has ducted AC but I could do one for shits and Giggles for the garage I spose.

What are you going to do with the heat you make? Use a HE for heating the house water?  I was thinking of a trigen with my lister engine but I have been playing with solar panels this last year and they are all to easy, cheap, quite and set and forget to worry about anything else.  For me it's easiest and neatest to just make power, back feed the house and then run everything electrically.

I'm interested in how you are going to do the evap side with a FPHE. How are you going to incorporate the TX valve?  To the best of my knowledge the system needs to be metered. Are you going to fab something up from the original evap and then shoot that into the HE?  I suppose the condensor is a bit irrelevant as long as the system is gassed accordingly.

I have been using LPG in my vehicles and it's great.  I dose the system at half normal pressure and get better results than when I had R134.  All the AC gas is going to LPG based now anyway.

Doing the homework, I found car AC's are around the midway output between a small and medium split household system.  I was wondering if it' would be possible to run 2 compressors at once on the same system and upsize everything accordingly.  2 Evaps and 2 Condensers or maybe a bigger one like you plan on.  As long as the compressors were the same size, Ideally the same units, can't really see a problem other than possibly having to have the pipework upgraded to account for the higher liquid/ gas flows.  Again, Fill the system using pressures rather than weights and should be good to go.

Other thing I'm doing the mental arithmetic on atm is a chiller design using evaporating water.  Thought is to use a cascading water feature outside and bring the air from the chilled water inside.  Not as effective as AC but much more economical from a power and wear and tear POV on those days just a bit hot for comfort.  This could be as simple as pumping the water through a small car Radiator  with an electric fan.
hard part is making it look presentable and not something from a shack tacked onto the upmarket house.

Be interested to see what you come up with on teh engine driven AC. Last time I searched google and YT I couldn't find anyone having done it DIY before.

[Fordguy64]

I found a great diy sure and they cover a ton of refrigerant details.. many people have made their own systems and they work well

Ecorenovator.org

The txv is pretty simple and required for any kind of variable capacity system. It has a temp bulb that attaches to the output side of the evaporator to throttle the flow of refrigerant. You just have to size it accordingly to the size of your system. And yes you can run two compressors in parrellel to double capacity. Again if everything is sized correctly.. I have a small solar array already in place and it is nice. Sadly the wife doesn't like to look at them so I'm not sure if I'll be able to get more lol but we shall see

My end goal would be to actually have this system as a ground source heat pump. Both evap and condenser would be bphx with one side running into a ground loop and the other getting pumped into the house with an air to water heat exchanger. Winter time I have crap solar conditions.. lots of big trees and just clouds all the time. So the plan would be to have summer time be solar power and then have the trigger for winter heating.

[Fordguy64]

JUst gotta order one last part to get the belt stuff together. Then mount it all up to the motor. Then do some plumbing lol

[RJ]

Very interesting in seeing how this comes together. Living in the SE now it really makes sense during a power outage to consider this option. Running the compressors take such large units and when they're not running your spinning a huge generator so utilize a few KW at most.

[glort]

Running the compressors take such large units and when they're not running your spinning a huge generator so utilize a few KW at most.

Not as bad as you may think. Fuel consumption is based on load more than anything so when the compressor kicks out, the genny would be using very little Fuel. Also because It's under no load, wear is next to nothing at all as well.

I was trying to Find a Diesel Driven Reefer unit. They are not easy to come by here and far too expensive to buy for back yard projects and mucking around. They have some impressive cooling capacity and all set up to begin with. Not the quietest thing around but effective.

[Fordguy64]

I am still working on this. Gotta machine a few parts and then I can start assembling

[glort]

Looking forward to seeing how you go with it and detailed explanations illustrated with Pics and Vids!  :0)

Hasn't dropped below mid 30o C here for about a fortnight. AC is getting a huge workout.  Thank heavens I put solar on the roof and bought a bunch of panels today to take it over 10KW.
I was thinking that would be enough but I'm now thinking to go 15 To be sure!

Also just bought another lister so I could run a pretty decent AC unit with that.

[Fordguy64]

So some general info.. from what I've found a 13k btu r22 compressor has a 18cc capacity per revolution. Assuming it runs at 3600rpm (I can't find what speed it runs at) that turns into 64,800 cc a min for 13kbtu. The car ac compressor is between 100-120cc per revolution. To get to 3 tons heating/cooling the car compressor only needs to spin at roughly 1700 rpm. Obviously the nice thing about this system is that I can very the rpm of the motor a little to match the heatin/cooling load. The pulley I have for the drive is 6.25" and the pulley on the compressor is 4". That puts my engine rpm at 1100 and I don't think the little z482 will have the power to run it at that rpm but I'll give it a try lol I'll just have to keep an eye out for another pulley for the motor.

Currently working on attaching the pulley I have to the motor. Then I just need to mount everything up and get the belt on. Then some brazing and vac the system down 

[Fordguy64]

So I found a source that says most compressors run at 2400rpm.. if that's true that changes the 13kbtu unit to 43000 cc a min.
That also changes the rpm of the car ac to around 1200 and that drops motor rpm way to low.. wish I would have done all this math sooner lol but I'm going to try it anyway

[Fordguy64]

a few pics of the turd... lol lots to do still. i have a 5kw 240v gen head that id like to get in this thing. im going to try to design a way to put an autmotive ac clutch on it so i can turn it off when not in use.  still in the layout stages obviously. just trying to make sure i have room for 3 FPHE and an exhaust HE.

[Fordguy64]

Might be getting a different ac compressor. I recently learned that some newer cars have a variable displacement compressor. Means it spins all the time but you can control the output like you can with an alternator. That will play nice with charging batteries and cooling/heating loads..