Charging The System

H E AT C O N T R O L L E R , I N C . WAT E R - S O U R C E H E AT P U M P S

R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 A

R e v. : 5 J u n e , 2 0 0 8

Evacuation Of The Lineset And Coil

The line set and coil must be evacuated to at least 500 microns to remove any moisture and noncondensables. Evacuate the system through both service ports in the shipping position (full CW in - see table 5) to prevent false readings on the gauge because of pressure drop through service ports. A vacuum gauge or thermistor capable of accurately meausuring the vacuum depth is crucial in determining if the system is ready for charging. If the system meets the requirements in Figure 14, it is ready for charging.

Figure 14: Evacuation Graph

Refrigeration Installation

There are two methods of charging a refrigerant system. One method is the total charge method, where the volume of the system is determined and the refrigerant is measured and added into the evacuated system. The other method is the partial charge method where a small initial charge is added to an evacuated system, and remaining refrigerant added during operation.

Total Charge Method - See Table 4 for the compressor section basic charge. For line sets with 3/8” liquid lines add 0.6 ounces of refrigerant to the basic charge for every installed foot of liquid line [0.6 grams per cm]. Add 1.2 oz. per foot [1.1 grams per cm] if using l/2” line. Once the total charge is determined, the factory pre-charge (Table 4) is subtracted and the remainder is the amount needed to be added to the system. This method should be used with the ARI matched air handler.

EXAMPLE: R22 model 048 with 40 feet [12 meters] of installed liquid line (3/8” O.D.). The basic charge of model 048 is 115 oz [3.26 kg]. The 40 ft. [12 meter] 3/8” line set requires 24 oz. [0.72 kg] (40 ft. x 0.6 oz./ft = 24 oz. -- 1200cm x 0.6g/cm = 720g). Total charge = 115 + 24 = 139 oz [3.26 +

0.72= 3.98 kg]. The compressor section is shipped from the factory with 130 oz. [3.69 kg] of refrigerant (for 25 ft [7.6m] lineset), so the amount to be added is 9 oz. [0.29 kg] (total charge - shipped charge = charge to be added).

Table 6a: R-22 Charging Values

x NOTICE! x

NOTICE: Use tables 14a to 15 for superheat/subcooling values. These tables use discharge pressure (converted to saturation temperature) and liquid line temperature for subcooling calculations. If using liquid line pressure, subtract 3°F from the table values.

Table 6b: R-410A Charging Values

x NOTICE! x

20	H e a t C o n t r o l l e r, I n c . Wa t e r - S o u r c e H e a t i n g a n d C o o l i n g S y s t e m s