Technical Development Program. COMMERCIAL HVAC PACKAGED EQUIPMENT Split Systems PRESENTED BY: Ray Chow Sigler

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1 Technical Development Program COMMERCIAL HVAC PACKAGED EQUIPMENT Split Systems PRESENTED BY: Ray Chow Sigler

2 Menu Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Introduction System Basics System Components Accessories Controls Installation Summary

3 SECTION 1 SPLIT SYSTEMS Introduction

4 Objectives Identify applications that utilize the strengths of split systems Identify the components of split systems Understand the impact codes have on system application and selection Compare the differences in outdoor and indoor unit types Understand key installation issues Section 1 Introduction

5 Split Systems Components Condensing Unit Indoor Unit AHU (Fan Coil) Indoor Unit Furnace And Coil Section 1 Introduction

heat Heat pump Furnace with coil Utilize packaged

6 Split Systems Residential to large commercial ¾ to 120+ tons Applications Cooling only Cooling with heat Heat pump Furnace with coil Utilize packaged products in an applied manner Section 1 Introduction

ARI System Classification Single Package Remote Condenser

Evap Comp Cond Fan Evap Comp + Cond Fan Evap Heat Comp + Cond

Cond Comp Year Round Condensing Unit with Coil + Fan Fan Evap

categories ARI has categories for air, evaporative or

7 ARI System Classification Single Package Remote Condenser Year Round Remote Condenser Condensing Unit with Coil Fan Evap Comp Cond Fan Evap Comp + Cond Fan Evap Heat Comp + Cond Evap + Cond Comp Condensing Unit with Coil + Fan Fan Evap + Cond Comp Year Round Condensing Unit with Coil + Fan Fan Evap Heat + Cond Comp Split Systems 5 ARI cooling split system categories ARI has categories for air, evaporative or water-cooled Plus 4 ARI heat pump categories (not shown) Section 1 Introduction

8 SECTION 2 SPLIT SYSTEMS System Basics

9 Split System Basics Indoor Unit Outdoor Unit Liquid Line Warm-Temp., High-Pressure Liquid Filter Drier Suction Line Low-Temp., Low-Pressure Vapor Sight Glass Liquid Line Solenoid Valve Section 2 System Basics

10 Why Use a Split System? Flexibility Aesthetics Duct design Performance Zoning Section 2 System Basics

11 Flexibility Mix and match indoor and outdoor units Closely match load requirements Use only manufacturer s approved combinations 10-ton AHU OR 10-ton condensing unit 12½-ton AHU Section 2 System Basics

12 Residential & Duct Free Systems Section 2 System Basics

13 Condensing units include: Controls Condensing Units Compressors Condenser Coil Section 2 System Basics

14 Typical Condensing Units Section 2 System Basics

15 Typical Indoor Unit Cased Evaporator Coils Packaged AHU Central Station AHU Section 2 System Basics

16 Heat Pump System Indoor Unit Evaporator in cooling Condenser in heating Outdoor Unit Condenser in cooling Evaporator in heating Section 2 System Basics

17 Refrigerant Circuits Single Circuit Dual Circuit Section 2 System Basics

18 Indoor Unit Refrigerant Circuits Single Circuit Distributor Dual Circuit Solenoid TXV LIQUID LINE LIQUID LINE TXV Filter Drier Distributor Section 2 System Basics

19 ARI Standards Standard # 210/240 Applies to Unitary Air Conditioners Air Source Unitary Heat Pumps (Air-Cooled) Capacity Range <65,000 Btuh <65,000 Btuh 340/360 Unitary Air Conditioners Air Source Unitary Heat Pumps (Air-Cooled) 65,000 to <250,000 Btuh 65,000 to <250,000 Btuh 365 Air Conditioning Condensing Units >135,000 to <250,000 Btuh Section 2 System Basics

20 EER EER = EER EER EER Capacity( Btuh) Total Power Input( Watts) Example 25-ton condensing ARI conditions EER = = Capacity(Btuh) Total Power Input (Watts) ( = 25.9 = MBtuh + 3.1) kw Section 2 System Basics

21 Net vs. Gross Capacity System EER = Net Capacity Total Power (Btuh) Input Net Capacity = Gross Capacity - IFM Heat Section 2 System Basics

22 BHP Required AHU Size Airflow cfm External Static Pressure (in. wg) rpm bhp rpm bhp rpm bhp rpm bhp , Interpolate to derive bhp for 0.44 in. wg 0.44 in. wg = 4.00 bhp Section 2 System Basics

23 IFM Heat IFM Heat = (bhp * 746) Motor Efficiency IFM Heat = (4.00 * 746) 0.83 IFM Heat = 3,595 Watts 3,595 Watts * Btuh Watts = 12,274 Btuh Section 2 System Basics

24 Net Capacity Net Capacity = Gross Capacity IFM Heat Net Capacity = 294 IFM Heat Net Capacity = 282 MBtuh Section 2 System Basics

25 Total Power Input OFM power per motor = ( bhp * 746) Motor Efficiency Now calculate Total Power Input using data from previous slides Total Power Input = Compressor power + IFM power + ODF power Total Total Power Power Input Input = = kw kw kw kw Section 2 System Basics

26 System EER System EER for the 25-ton example system: System EER System EER System EER = = = Net Cooling Capacity Total Power Input 282 MBtuh 29.5 kw 9.6 Section 2 System Basics

27 SEER Applies to: Single phase power only Capacity less than 60 MBtuh Calculated at three conditions and cycle test: 80/67 F return air, 95 F outdoor air 80/67 F return air, 82 F outdoor air 80/57 F return air, 82 F outdoor air 80/57 F cycle test, 82 F outdoor air Requires laboratory testing and is not calculated in the field. Section 2 System Basics

IPLV FOR ALL 3 Æ AND WATER-COOLED UNITS AND AIR-COOLED UNITS

than full capacity Applicable only to equipment with more

capacity step PART LOAD FACTOR CURVE Equipment with greater

requirements of the space Unless equipment is always

28 IPLV FOR ALL 3 Æ AND WATER-COOLED UNITS AND AIR-COOLED UNITS ABOVE 60 MBH CAPACITY Evaluate equipment efficiency at less than full capacity Applicable only to equipment with more than one stage of capacity Weighted average of EER at each capacity step PART LOAD FACTOR CURVE Equipment with greater number of capacity steps can more closely match the load requirements of the space Unless equipment is always operated at 100% capacity, a higher IPLV is preferred Section 2 System Basics

29 Coefficient of Performance Applies to heat pumps that operate on 3-phase power only Measures efficiency while operating in the heating mode A higher COP indicates a more efficient heat pump COP = Net Capacity ( Watts) Total Power Input ( Watts) Section 2 System Basics

30 Heating Seasonal Performance Factor HSPF: Applies to heat pumps that operate on single phase power and have a cooling capacity of < 5.5 tons only Is similar to SEER in that it measures the seasonally adjusted efficiency of a heat pump Accounts for defrost and required electric heat A higher HSPF is a more efficient heat pump Section 2 System Basics

31 Energy Codes Many codes rely on ASHRAE 90.1 that sets minimum efficiency requirements. Air-Cooled Split System Requirements Performance requirements < 65,000 Btuh 10.0 SEER 1Ø 65,000 < 135,000 Btuh 10.3 EER 135,000 < 240,000 Btuh 9.7 EER 240,000 < 760,000 Btuh 9.5 EER / 9.7 IPLV 760,000 Btuh 9.2 EER / 9.4 IPLV Control requirements Motor hp limits Economizer requirements Heat pump requirements Section 2 System Basics

32 IAQ and Sustainability IAQ ASHRAE 62 Limits maximum humidity to less than 65% Indoor unit condensate control Indoor unit ventilation capability Sustainable Design LEED Require meeting ASHRAE 90.1 efficiency and ASHRAE 62 IAQ features Optimized energy performance and IAQ Split System mix and matches provide better humidity control and flexibility to meet these requirements Section 2 System Basics

33 SECTION 3 SPLIT SYSTEMS System Components

34 Rules of Thumb Rules of Thumb are considered to be guidelines only Airflow: cfm per nominal ton - Range of 300 to 500 cfm per ton - Today, 350 cfm per ton may be more appropriate Mix and Match: - Nominal and one size up, sometimes one size down, others depend (consult the manufacturer) Line Length: - Keep them at 100 ft or less Section 3 System Components

35 Operating Limits Cooling only equipment: Maximum outdoor air temperature Minimum return air temperature Maximum return air temperature Saturated suction temperature range Maximum discharge superheat Minimum discharge superheat 115 F 55 F 95 F 25 to 55 F 275 F 60 F Typical saturated suction temperature range for air conditioning duty is 40 to 50 F Heat Pumps: Maximum outdoor air operating temperature in heating Minimum outdoor air operating temperature in heating 75 F 20 F Section 3 System Components

36 Outdoor Units Residential 1½ to 5 ton Commercial 6 to 100+ ton Duct Free ¾ to 5 ton Section 3 System Components

37 Semi-Hermetic Compressor Cylinder Unloader Repairable Capacity Control Section 3 System Components

38 Multiple Compressors Dual Scroll Dual Semi-Hermetic Reciprocating Section 3 System Components

39 Multiple Condensing Units Dual Circuit Indoor Unit 2 nd Stage Condensing Unit 1 st Stage Condensing Unit Section 3 System Components

40 Hot Gas Bypass Liquid Solenoid Valve Evaporator TXV Sight Glass Compressor Hot Gas Solenoid Valve Protects system in low load conditions Prevents coil icing Injects hot gas at indoor unit Activates at minimum step of cooling only Filter Drier Discharge Bypass Valve Condenser Section 3 System Components

41 Alternative Condensing Unit Solutions Triple-Split Water-Cooled Condensing Unit Condenser To indoor coil From indoor coil Compressor Section 3 System Components

42 Heat Pump System Check Valves TXV with bypass OUTDOOR COIL 4-Way Valve Compressor INDOOR COIL Accurator Accumulator Heating Mode Bi-flow Filter Drier Bi-flow TXV Section 3 System Components

43 Heat Pump System Check Valves TXV with bypass OUTDOOR COIL Filter Drier 4-Way Valve Compressor INDOOR COIL Accurator Accumulator Cooling Mode Bi-flow Filter Drier Bi-flow TXV Section 3 System Components

44 Indoor Unit Air Handler 6 to 30 ton Packaged AHU with limited options Central Station AHU Section 3 System Components

45 IAQ Features Double-Wall UV-c Lamps Double-Wall Dual-Density Insulation Foil-Face Insulation UV-c Lamps Section 3 System Components

46 Constant Volume AHU Variable pitch pulley is set at required airflow at first unit start-up Fan then operates at a constant speed Section 3 System Components

47 VAV Application VFD Inlet Guide Vanes COIL MOTOR SUPPLY FAN VAV Terminal Section 3 System Components

48 VAV Requirements Filter Drier Capacity Control Solenoid TXV Distributor LIQUID LINE Sight Glass Indoor Unit At least two circuits Equipped with capacity control valve(s) Section 3 System Components

49 VAV Requirements Outdoor Unit Multiple stages of capacity Electric control of capacity stages Suction line accumulators Interface with VAV controller Section 3 System Components

50 VAV Controller Typically controls discharge air temperature Controls: Compressors Stages of capacity Fans Section 3 System Components

51 Cased Evaporator Coils Installed in duct A coil design, installed on twinned furnaces Section 3 System Components

52 Residential Coils Cased Uncased Section 3 System Components

53 SECTION 4 SPLIT SYSTEMS Accessories

54 Economizer Free Cooling Outdoor air Control types Dry bulb Enthalpy Differential enthalpy CO 2 Demand controlled ventilation (DCV) Return air Section 4 Accessories

55 Heating Accessories Electric Heat Accessory on Packaged AHU Hot Water or Steam Coil on Packaged AHU Section 4 Accessories

56 Furnaces Horizontal Furnace with downstream cooling coil Twinned Furnaces Section 4 Accessories

57 Accessories Plenum Condensate Drain Return Air Grille Subbase Section 4 Accessories

58 SECTION 5 SPLIT SYSTEMS Controls

59 Controls - Thermostat Simple control requirements: Indoor fan Outdoor fan(s) Compressor(s) Liquid line solenoid Section 5 Controls

60 Two-Stage Thermostat Y1 initiates 1 st stage cooling Y2 initiates 2 nd stage cooling Section 5 Controls

61 Capacity Control Solenoid Valve Y1 initiates 1 st stage cooling AND opens the liquid line solenoid valve Y2 opens the liquid line solenoid valve Section 5 Controls

62 DDC Control User Interface Section 5 Controls

gas thermostat Oil pressure switch Cycle protection

63 Safeties Outdoor Unit High-pressure switch Low-pressure switch Indoor Unit Motor protection Airflow switch Discharge gas thermostat Oil pressure switch Cycle protection Compressor overtemperature protection Circuit breakers Section 5 Controls

UNIT 38AR Z007 Z008 Z012 S012 COND TEMP (F) Low Ambient Control MINIMUM OUTDOOR-AIR OPERATING TEMPERATURE MINIMUM OUTDOOR TEMP (F) 80 80 80 80 80 Std.

64 UNIT 38AR Z007 Z008 Z012 S012 COND TEMP (F) Low Ambient Control MINIMUM OUTDOOR-AIR OPERATING TEMPERATURE MINIMUM OUTDOOR TEMP (F) Std D Proper operation of expansion device at low outdoor temps Minimum outdoor air operating temperature Maintain minimum SCT With Motormaster Control Low ambient controller OFM motor controller -20 Motormaster Control Section 5 Controls

65 Fan Cycling Pressure Switch Intermediate Season SCT Control Device #2 OFM Motor #1 Turn off #2 OFM motor when SCT falls too low DO NOT cycle #1 OFM motor on/off because a speed control device is required Section 5 Controls

66 Wind Baffles Wind baffles may be required in areas of sustained high winds, at least on the windward side. WIND BAFFLE Section 5 Controls

67 SECTION 6 SPLIT SYSTEMS Installation

68 Power Supply Minimum Circuit Ampacity (MCA) determines required wire size MCA = (1.25 * Current of largest motor) + Sum of all other loads MCA of a condensing unit = (1.25 * RLA of compressor) + (FLA of OFM motors + Control amps) MCA of indoor unit with electric heat = (1.25 * FLA of largest motor) + (1.25 * FLA of electric heater) + Sum of all other loads Section 6 Installation

69 MOCP Defines MAXIMUM size of overcurrent protective device A smaller device may be used, if nuisance trips are not a problem MOCP = (2.25 * Current of largest motor) + Sum of all other loads Round down to the next lower standard rating, but not lower than the MCA value Section 6 Installation

70 Protective Device Fuse or Circuit Breaker HACR Breaker Usage defined by code and availability Section 6 Installation

71 Disconnect Located within line of sight Field-installed or factory-supplied Fused or non-fused CONDENSING UNIT FUSED DISCONNECT SWITCH Field-installed disconnect Factory-installed disconnect Section 6 Installation

72 Installation Consult manufacturer s instructions Locate indoor and outdoor units as close together as possible Keep refrigerant piping as short as possible Provide adequate clearance for service access and airflow Section 6 Installation

Consider the effect of sound when recommending unit

73 Sound Understand sound power (both indoor and outdoor) Utilize sound reduction accessories when available Consider the effect of sound when recommending unit location Isolate and support refrigerant tubing Section 6 Installation

74 Elevation LIQUID LINE 38AKS UNITS UNIT 38AKS MAX ALLOW. LIFT (ft) Max Allow. Pressure Drop (psi) LIQUID LINE Max Allow. Temp Loss ( F) 7 2 NOTE: Data above is for units at 45 F saturated suction and 95 F entering air. LIQUID LIFT Section 6 Installation

75 Suction Riser Refrigerant velocity in suction riser must be high enough to entrain compressor oil with the refrigerant Double suction riser or reduced diameter riser may be required Consult manufacturer s recommendations Section 6 Installation

76 Maximum Length of Refrigerant Piping Piping length depends on the application Heat pumps 100 linear feet Consult manufacturer s recommendations Section 6 Installation

77 Long Line Applications LONG LINE = 75 LINEAR FEET OR LONGER Lift vs. Run Long Lines Require: 1. Liquid line solenoid valve(s) 2. Suction line accumulator(s) LIFT Section 6 Installation

78 SECTION 7 SPLIT SYSTEMS Summary

79 Summary Identified applications that utilize the strengths of split systems Identified the components of split systems Discussed the impact that codes have on system application and selection Compared the differences in outdoor and indoor unit types Reviewed key installation issues Section 8 Summary

Work Session 1 SPLIT SYSTEMS Work Session 1 Multiple-choice questions may have more than one correct answer;

a) an indoor unit only c) an indoor and an out unit b) a compressor, an indoor fan, an evapora- d) a

2. True or False? All commercial split systems are at least dual circuit. 3. True or False? Net capacity will always be greater than gross capacity.

80 Work Session 1 SPLIT SYSTEMS Work Session 1 Multiple-choice questions may have more than one correct answer; identify all correct selections. 1. A typical commercial split system includes. a) an indoor unit only c) an indoor and an out unit b) a compressor, an indoor fan, an evapora- d) a compressor, an indoor fan, an evapotor and condenser as one or more rator and condenser as a package sections 2. True or False? All commercial split systems are at least dual circuit. 3. True or False? Net capacity will always be greater than gross capacity. 4. SEER applies to a. units which are cooling and heat single phase units under 65,000 Btuh Work Session 1

81 Technical Development Program Thank You This completes the presentation. TDP-634 Split Systems Artwork from Symbol Library used by permission of Software Toolbox

COMMERCIAL HVAC PACKAGED EQUIPMENT. Split Systems

COMMERCIAL HVAC PACKAGED EQUIPMENT Split Systems Technical Development Programs (TDP) are modules of technical training on HVAC theory, system design, equipment selection and application topics. They are