1. James McIntyre VRF Training Manager V5 Key Components

2. Key Components Indoor Units

3. Electronic Expansion Valves Each indoor unit uses an Electronic Expansion Valve Each indoor unit uses an Electronic Expansion Valve More accurate than other metering devices More accurate than other metering devices Varies the volume of refrigerant in a coil Varies the volume of refrigerant in a coil

4. Temperature Sensors Each indoor unit uses air and pipe temperature sensors, also known as thermistors Each indoor unit uses air and pipe temperature sensors, also known as thermistors Resistance changes with temperature, raising or lowering the DC voltage drop Resistance changes with temperature, raising or lowering the DC voltage drop This voltage drop is then used to calculate the temperature This voltage drop is then used to calculate the temperature

5. Pipe Sensors Every pipe temperature sensor has a 20K Ohm rating (rating is at 77 degrees) Every pipe temperature sensor has a 20K Ohm rating (rating is at 77 degrees) Metal coated for quick-sensing Metal coated for quick-sensing Inside copper tube soldered to pipe for accuracy Inside copper tube soldered to pipe for accuracy

6. Air Sensors Every air temperature sensor has a 15K Ohm rating (rating is at 77 degrees) Every air temperature sensor has a 15K Ohm rating (rating is at 77 degrees) Rubber coated to protect from elements Rubber coated to protect from elements Often in return air stream, sometimes in space Often in return air stream, sometimes in space

7. Indoor Unit Temperature Sensors All indoor units have at least three temperature sensors All indoor units have at least three temperature sensors R1T=Space, R4T=Inlet, R2T=Outlet R1T=Space, R4T=Inlet, R2T=Outlet RT1 RT4 RT2

8. Equivalent Superheat Indoor unit determines capacity by calculating equivalent superheat Indoor unit determines capacity by calculating equivalent superheat Outlet-Inlet=Equivalent Superheat Outlet-Inlet=Equivalent Superheat RT4 RT2 53 ° 46 ° 53 ° 46 ° ___ 7 ° -

9. Temperature Differential Difference between return or space temperature and setpoint Difference between return or space temperature and setpoint RT4 RT2 RT1 72 ° 73 ° 78 ° EEV opens more

10. Fresh Air Processor Temperature Sensors Fresh Air processor has Supply Temp. Sensor Fresh Air processor has Supply Temp. Sensor Supply Temp Sensor is used to maintain setpoint of air being supplied Supply Temp Sensor is used to maintain setpoint of air being supplied RT1 RT4 RT2 RT3

11. Fresh Air Processor Temperature Sensors Return air sensor is used to determine the mode of operation, like free cooling Return air sensor is used to determine the mode of operation, like free cooling Similar operation to traditional fresh air Similar operation to traditional fresh air RT1 RT4 RT2 RT3

12. Other Sensors The wired controller has a built-in temperature sensor The wired controller has a built-in temperature sensor Sensor priority is configurable Sensor priority is configurable

13. Indoor Unit Fan Motors All indoor units have Brushless Digitally Commutated Motors (BLDC) All indoor units have Brushless Digitally Commutated Motors (BLDC) True variable-speed motor True variable-speed motor Can automatically adjust speed to load (auto fan speed) Can automatically adjust speed to load (auto fan speed)

14. Indoor Unit Coil Indoor coils are coated with a hydrophilic (water repelling) film Indoor coils are coated with a hydrophilic (water repelling) film Require less maintenance over time Require less maintenance over time

15. Indoor Unit Lift Pumps Many units have condensate lift pumps Many units have condensate lift pumps Generally about 39 inch lift (check manual) Generally about 39 inch lift (check manual) No need for priming, can run dry with no damage No need for priming, can run dry with no damage

16. Indoor Unit Float Switches Many units have float switches Many units have float switches Only used to detect overflow Only used to detect overflow Prolonged or repeated on/off results in error code Prolonged or repeated on/off results in error code Magnetic switch Magnetic switch

17. Key Components Outdoor Units

18. Compressors V5 VRF uses only Digitally Commutated Compressors V5 VRF uses only Digitally Commutated Compressors

19. Heat Pump Compressors 6 and 8 ton has one; 10 ton has two 6 and 8 ton has one; 10 ton has two 6 and 8 Ton 10 Ton

20. Heat Recovery Compressors 6 and 8 Ton 10 Ton 6 and 8 ton has one; 10 ton has two 6 and 8 ton has one; 10 ton has two

21. Oil Separator Separates oil from discharge gas Separates oil from discharge gas Ensures 95% or more oil remains in outdoor unit Ensures 95% or more oil remains in outdoor unit Oil Return Oil Balance Inlet Outlet

22. Gas-liquid Separator Also known as a suction accumulator Also known as a suction accumulator Separates liquid from the suction line Separates liquid from the suction line Prevents liquid from returning to compressor during flooded operation Prevents liquid from returning to compressor during flooded operation

23. Gas-liquid Separator How it works: How it works: Suction Line from Indoor Units Suction Line to Compressor Liquid/Vapor mixture enters accumulator Liquid falls to the bottom allowing only vapor to flow to the compressors

24. Refrigerant Adjustment Tank Acts as a storage tank for refrigerant during low demand Acts as a storage tank for refrigerant during low demand Amount stored is controlled by two solenoid valves Amount stored is controlled by two solenoid valves

25. Refrigerant Adjustment Tank How it works: How it works: Hot Gas from Discharge Line From Liquid Line Liquid Intake Valve Opens allowing liquid to enter tank Pressure Valve opens allowing hot gas to pressurize the tank Liquid Intake ValvePressure Valve Drain Valve for Cooling Opens Drain Valve for Cooling opens sending liquid to accumulator Opens To Accumulator

26. Hot Gas Bypass Circuit Hot gas bypass circuit ensures pressure equalization when compressor is off Hot gas bypass circuit ensures pressure equalization when compressor is off Serves as a compressor unloader during low ambient conditions for cooling Serves as a compressor unloader during low ambient conditions for cooling Hot Gas Bypass Valve

27. Unloading Valve Prevents excessive high side (liquid) pressure Prevents excessive high side (liquid) pressure Upon opening, liquid is sent back to the Gas-liquid Separator (also known as a Suction Accumulator) Upon opening, liquid is sent back to the Gas-liquid Separator (also known as a Suction Accumulator) Unloading Valve

28. Outdoor Unit Main EEV Main outdoor EEV serves as the metering device for the system during heating operation Main outdoor EEV serves as the metering device for the system during heating operation During cooling, EEV is bypassed with a check valve During cooling, EEV is bypassed with a check valve EEV for Heating

29. Subcooling EEV Subcooling EEV is the metering device for the subcooling circuit (or subcooler) Subcooling EEV is the metering device for the subcooling circuit (or subcooler) Controlled by the inlet and outlet subcooling sensors Controlled by the inlet and outlet subcooling sensors Subcooling EEV

30. Subcooler Used only in cooling Used only in cooling Ensures sufficient subcooled liquid to indoor units Ensures sufficient subcooled liquid to indoor units Especially useful in very light load conditions Especially useful in very light load conditions Helps maintain a “Solid column” of liquid Helps maintain a “Solid column” of liquid Plate heat exchanger Plate heat exchanger

31. Subcooling Circuit How it works: How it works: Subcooling EEV ClosedOpens  To Indoor Units  Warm Liquid Cooler Liquid

32. Discharge and Comp. Shell Sensors Discharge and Compressor Shell sensors used for compressor protection Discharge and Compressor Shell sensors used for compressor protection 50k ohm @77°F 50k ohm @77°F If discharge rises over 215°F, indoor EEV’s are driven open If discharge rises over 215°F, indoor EEV’s are driven open If over 230°F compressor slows down If over 230°F compressor slows down If over 244°F system shuts down in error (E4) If over 244°F system shuts down in error (E4) Discharge Temperature Sensor Compressor Shell Sensor

33. High Pressure Switch Protects system from high pressure condidtion Protects system from high pressure condidtion Opens at 609 psi Opens at 609 psi

34. Low Pressure Sensor Measures pressure of true suction Measures pressure of true suction Used for low pressure protection and compressor speed control Used for low pressure protection and compressor speed control To Suction Accumulator Low Pressure Sensor or Transducer

35. High Pressure Sensor Measures discharge pressure Measures discharge pressure Used for high pressure protection and compressor speed control Used for high pressure protection and compressor speed control To Condenser High Pressure Sensor or Transducer

36. Defrost Temperature Sensor Used for judging the starting, stopping, and the duration of, defrosting operation Used for judging the starting, stopping, and the duration of, defrosting operation 20k ohms at 77 degrees 20k ohms at 77 degrees

37. Refrigerant Flow Cooling Cooling Sub- Cooler Suction Accumulator Refrigerant Adjustment Tank Oil Separator Condenser To Indoor Units 4-Way or Reversing Valve From Indoor Units Subcooling EEV Compressor Cooling Operation Cooling Operation

38. Refrigerant Flow Heating Heating Sub- Cooler Suction Accumulator Refrigerant Adjustment Tank Oil Separator Evaporator To Indoor Units 4-Way or Reversing Valve From Indoor Units Subcooling EEV Compressor Main EEV 4-Way or Reversing Valve Heating Operation Heating Operation

39. Refrigerant Flow Heat Recovery Mostly Cooling Heat Recovery Mostly Cooling Sub- Cooler Suction Accumulator Refrigerant Adjustment Tank Oil Separator Condenser To Indoor Units 4-Way or Reversing Valve From Indoor Units Subcooling EEV Compressor To Indoor Units 4-Way or Reversing Valve Heat Recovery Mostly Cooling Heat Recovery Mostly Cooling

40. Refrigerant Flow Heat Recovery Mostly Heating Heat Recovery Mostly Heating Sub- Cooler Suction Accumulator Refrigerant Adjustment Tank Oil Separator Evaporator To Indoor Units 4-Way or Reversing Valve From Indoor Units Subcooling EEV Compressor Main EEV From Indoor Units 4-Way or Reversing Valve Heat Recovery Mostly Heating Heat Recovery Mostly Heating

42. Nortek Global HVAC is a subsidiary of Nortek Inc. © 2016 Nortek Inc., All Rights Reserved.