Building bench A/C units.. anyone done it?

Leggie on Tue September 03, 2013 7:24 PM

I was contemplating building a full scale emulation unit built on a pallet, but I am not sure what I would need to use for a power source.

I read a journal published somewhere that some setup needs about 7hp of input.
Variable displacement compressors work by increasing the torque imposed on the shaft. So, a 10 hp engine may produce 10 hp at the rated speed, but if the engine speed was dropped and compressor increases the displacement, would it still keep up or do I need to vary the speed with something like hydrostatic control?

GM Tech on Tue September 03, 2013 8:59 PM

If you just want to demonstrate how it works- I built one once where I ctanked the compressor- used a copper coil for evap and another copper coil for condenser- and a a capillary tube for the orifice I used a used compressor so it would not be too tight to turn crank- - the evap side would actually frost- had gages on top- pretty neat- I have photo somewhere

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

Edited: Tue September 03, 2013 at 9:43 PM by GM Tech

Leggie on Mon September 16, 2013 10:48 AM

No, I need a realistic system with different valves in place, so I can simulate various problems to create the symptoms.

iceman2555 on Mon September 16, 2013 12:35 PM

There is already a custom unit in production. Includes a complete AC system with dash that is totally functional. I shall try to locate the vendor and post back to you. The unit is quite extensive in it's ability to perform and allow for various failure modes for training purposes. If memory serves me correctly, the unit was app $25k. Included many parts that were constructed of a transparent material so that the actual function of the part could be visualized. It is an orifice tube system. Very impressive display.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

iceman2555 on Wed September 18, 2013 12:14 PM

Check this web site for a stand alone unit. I have seen this is practice and it does an excellent job for training.

http://www.merced-ac.com/

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

mk378 on Thu September 19, 2013 8:09 PM