Live evap but no air blowing, parallel evaps in coach HVAC

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bohica2xo
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Re: Live evap but no air blowing, parallel evaps in coach HVAC

Post by bohica2xo »

Too much oil can be as big a problem as too little.

Multiple evaporators are done on millions of SUV's - and just as may mini-split HVAC units in homes.

Look here for a good "too much oil" tale
https://autoacforum.com/viewtopic.php?f ... fire+truck
DetroitAC
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Location: SE Michigan

Re: Live evap but no air blowing, parallel evaps in coach HVAC

Post by DetroitAC »

Al9, yes it would work, but a "turned off" evaporator with no airflow and a functioning TXV will be an oil separator. There will be a very tiny flow of refrigerant and oil into the evap and it's suction line, and not enough flow to move it back to the compressor with suction gas velocity. Put a solenoid valve in the liquid line, run all evaps occasionally (suction line might still be an oil trap), or just force all evaps to be running together. Oil return is still an issue even with large bus compressors like Bitzer, Carrier, Thermoking, those are expensive compressors, need to keep the oil at the sightglass level.
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