Condenser & Line Sets

1. Condenser & Line Sets

2. Condenser Location • Short piping runs are better • Shaded location • Air flow • Noise

3. Condenser Selection • Check matched systems capacity rating • Match to the load calculation • Data on internet • http://www.aridirectory.org/ari/unitary.html • Choose A/C or heat pump • Choose Spacepak as the indoor unit MFR • Go to: http://www.aridirectory.org/ari/ac.php • Match heat load to listed capacity

4. Refrigeration Lines • Keep piping as short and direct as possible • Properly insulate and seal • Trap when condensing unit above AHU • Sight glass at unit on long runs copyright Mestek, Inc. 2004

5. Refrigeration Lines • Always defer to Condenser manufacturer • Always use good refrigeration practices

6. Importance Of Proper Refrigerant Piping • Return oil to the compressor • Assure a solid column of liquid at the expansion device • Maximize system capacity and efficiency • Minimize refrigerant charge to improve reliability and ease servicing

7. Best Piping Practices • Check c. u. manufacturers recommendations for line size • Be careful not to kink coiled copper line sets • Use new type “L” or ACR copper tubing • Always use long radius angle fittings to reduce pressure drop • Account for vibration, weight and expansion when supporting piping • Insulate lines properly • Install a filter drier and a sight glass on the liquid line • Install a trap at the evaporator when the compressor is above it

8. Is ¾” Enough? • Determine the total equivalent length of the suction line • Calculate the velocity at min. & max. system capacities • For long vertical risers pipe may be downsized to increase velocity to acceptable levels. • At max. capacity, velocity should be less than 4000 fpm

9. Is 3/8” Enough ? • Yes • Determine total equivalent length of piping • Determine refrigerant velocity • Assure that there is min. 5ºF sub-cooling at the evaporator • Refrigerant velocity should not exceed 4000 fpm

10. Importance Of Proper Refrigerant Piping • Return oil to the compressor • Assure a solid column of liquid at the expansion device • Maximize system capacity and efficiency • Minimize refrigerant charge to improve reliability and ease servicing

11. What Size Is Right For My Job? • If possible check the condensing unit manufacturers recommendations.

12. To Braze Or Not To Braze ?

13. Soldering • Use solder with silver content • Requires only 450F heat • Stay Bright #8 Stay Clean Flux • Use flux only on male fitting

14. Brazing • Use a silver/phosphorus/copper alloy • between 5%-15% silver • Requires 1100 to 1500F heat • Must trickle 2 PSI dry nitrogen through piping system • Stops carbon deposit build up • Stay Silv 15 or Dynaflow • No flux required • When brazing brass or bronze Stay Silv white flux is required