Heat Controller VMH 27, VMH 18 Air Purging, Air purging with vacuum pump, Heat Controller, Inc

Heat Controller, Inc. INSTALLATION MANUAL VMH InverterFlex Mini-Split

Air Purging

Air and moisture in the refrigerant system have undesirable effects as indicated below:

•Pressure in the system rises.

•Operating current rises.

•Cooling or heating efficiency drops.

•Moisture in the refrigerant circuit may freeze and block capillary tubing.

•Water may lead to corrosion of parts in the refrigeration system.

Therefore, the indoor unit and tubing between the indoor and outdoor unit must be leak tested and evacuated to remove any noncondensables and moisture from the system.

Air purging with vacuum pump

Preparation

•Check that each tube(both liquid and gas side tubes) between the indoor and outdoor units have been properly connected and all wiring for the test run has been completed. Remove the service valve caps from both the gas and the liquid side on the outdoor unit. Note that both the liquid and the gas side service valves on the outdoor unit are kept closed at this stage.

•Pipe length and refrigerant amount:

Connective Pipe Length	Air Purging Method	Additional amount of refrigerant to be charged
Less than 16.5 ft. (5m)	Use vacuum pump	———————
More than 16.5 ft. (5m)	Use vacuum pump	(Pipe length-5m) 15g/m
		(Pipe length-16.5 ft.) x 5 oz/ft.

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