4. Hydronic System Basics SOURCE LOAD Source & Load connected by piping
5. Hydronic System Basics SOURCE LOAD Fluid is circulated by a pump
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8. Hydronic System Basics Let’s design a simple system together! Boiler 200,000 BTUh AHU Coil 20 GPM Boiler = 5’ TDH AHU = 10’ TDH Piping = ???
9. Hydronic System Basics Let’s design a simple system together! Rule of Thumb… Length x 1.5 to account for elbows and fittings. 2.94’ per 100’ of piping 100’ x 1.5 = 150’ 1.5 x 2.94’ = 4.41’ TDH
10. Hydronic System Basics Let’s design a simple system together! Boiler 200,000 BTUh AHU Coil 20 GPM Boiler = 5’ TDH AHU = 10’ TDH Piping = 4.41’ TDH System Capacity: 20 GPM @ 19.41’
12. Hydronic System Basics GPM 2 GPM 1 HEAD 2 RPM 2 RPM 1 HEAD 1 HP 2 HP 1 RPM 2 RPM 1 RPM 2 RPM 1 HP 2 HP 1 GPM 2 GPM 1 GPM 2 GPM 1 HEAD 2 HEAD 1 Affinity Laws 2 2 3 3 = = = = =
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16. Hydronic System Basics NPSHA & NPSHR P NPSHA P B Foot Check - (FC) h L Strainer - (S) P P P NPSHA = (+P B ) + (-FC) + (-h L ) + (-P P ) + (-S) Pipe Pressure Drop
17. Hydronic System Basics P NPSHA P B Foot Check - (FC) 10’ Strainer - (S) 8’ P NPSHA = (+P B ) + (-FC) + (-h L ) + (-P P ) + (-S) Pipe Pressure Drop P B - 14.7 PSI (34’) P NPSHA = (+34) + (-4) + (-10) + (-8) + (-3) P NPSHA = 9’ NPSHA & NPSHR - Suction Lift
18. Hydronic System Basics NPSHA & NPSHR - Flooded Suction P NPSHA 8’ Pipe Pressure Drop P B - 14.7 PSI (34’) Strainer - (S) 10’ P B P NPSHA = (+P B ) + (-FC) + (-h L ) + (-P P ) + (-S) P NPSHA = (+34) + (-4) + (+10) + (-8) + (-3) P NPSHA = 29’
19. Total system HEAD & FLOW requirements through two parallel pumps Total System Head 1/2 Total Flow 1/2 Total Flow Hydronic System Basics Parallel Pumps
20. Two pumps in operation Each pump Head (ft) Flow (gpm) Hydronic System Basics Parallel Pumps
21. Total system HEAD & FLOW requirements through two series pumps Total System Flow 1/2 Total Head 1/2 Total Head Hydronic System Basics Series Pumps
22. Hydronic System Design Flow (gpm) Two pumps in operation Each pump Head (ft) Series Pumps
56. Variable Flow Systems SOURCE SOURCE System Criteria 2 - 100 Ton Chillers 2 - 300 GPM @ 100’ Pumps Pumps 2 - 20HP No Standby System Pressure Drop Total of 75’ P Chiller Pressure Drop Total of 25’ P TOTAL INSTALLED HP - 40 HP LIMITED VARIABLE VOLUME - 30% MAX HP REDUCTION
57. Variable Flow Systems SOURCE SOURCE System Criteria 2 - 100 Ton Chillers 2 - 300 GPM @ 25’ Pumps 2 - 300 GPM @ 80’ Pumps Primary Pumps 2 - 3HP Secondary Pressure Drop Total of 80’ P Primary Pressure Drop Total of 25’ P Secondary Pumps 2 - 10 HP Running Standby TOTAL INSTALLED HP - 26 HP 2 - 10 HP VFDs w/ STAGING REQ’D
58. Variable Flow Systems DP Sensor Location – Sensor Across Coil Typical Setting Equals Design Pressure Drop Across the Coil, Control Valve, and Circuit Setter. Coil 10 - 15’ P.D. Control Valve 10 - 15’ P.D. Typical Total P.D. 20 -30’
72. Tenant Use Pumps Tower Condenser Tenant Unit Tenant Unit Main Building Chiller
73. Tenant Use Pumps PDt Main Building Chiller Hst Ht PDrp PDsp PDs PDpt PDc PDt - Tower Pressure Drop PDsp - Suction Pipe Pressure Drop PDs - Strainer Pressure Drop PDpt - Pump Trim Pressure Drop PDc - Condenser Pressure Drop PDrp - Return Pipe Pressure Drop Ht - Tower Height - Static Lift Hst - Building Static Height Condenser
74. Tenant Use Pumps PDt - 15’ Main Building Chiller Hst - 100’ Ht - 10’ PDrp - 8’ PDsp - 8’ PDs - 3’ PDpt - 6’ PDc - 25’ ONLY STATIC PRESSURE SEEN AT PRESSURE GAUGE ON SUCTION OF PUMP P1 - 43 PSI Pump OFF Condenser P1 P2
75. Tenant Use Pumps PDt - 15’ Main Building Chiller Hst - 100’ Ht - 10’ PDrp - 8’ PDsp - 8’ PDs - 3’ PDpt - 6’ PDc - 25’ SUCTION SIDE OF PUMP - STATIC PRESSURE MINUS PDsp. AND MINUS PDs P1 >> 100’ - 8’ - 3’ = 38.5 PSI DISCHARGE SIDE OF PUMP - SUCTION PRESSURE PLUS PUMP HEAD (75’) P2 >> 38.5 PSI + 75’ = 71 PSI Pump On Pump Head = PDsp + PDs + PDpt + PDc + PDrp + Ht + PDt Condenser P1 P2
76. Tenant Use Pumps PDt Main Building Chiller Hst Ht PDrpa PDspa PDs PDpt PDc Ht - Tower Height - Static Lift Hst - Building Static Height PDspb PDrpb Hsta Hstb PDtenant PDt - Tower Pressure Drop PDspa - Suction Pipe Pressure Drop a Length PDspb - Suction Pipe Pressure Drop b Length PDs - Strainer Pressure Drop PDpt - Pump Trim Pressure Drop PDc - Condenser Pressure Drop PDrpa - Return Pipe Pressure Drop a Length PDrp b- Return Pipe Pressure Drop b Length Pdtenant - Tenant Loop Total Pressure Drop Condenser Tenant Unit
77. Tenant Use Pumps PDt - 15’ Main Building Chiller Hst - 100’ Ht - 10’ Pdrpa - 6’ Pdspa - 6’ PDs - 3’ PDpt - 6’ PDc - 25’ PDspb - 2’ PDrpb - 2’ Hsta - 80’ Hstb - 20’ Pdtenant - 25’ Tenant Pump Off - Main Pump On P3 - STATIC PRESSURE A MINUS PDspa. P3 >> 80’ - 6’ = 32 PSI P4 - DISCHARGE SIDE OF PUMP - SUCTION PRESSURE PLUS PUMP HEAD (75’) MINUS PRESSURE DROPS P4 >> 71PSI - 6’ - 25’ - 20’ - 2’ = 48PSI Difference P3 - P4 = 16 PSI (37’) Condenser Tenant Unit P3 P4
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79. Tenant Use Pumps Tenant Use Pumps Must be with the rest of the condenser water pumping system in mind. Never size a tenant use system, for only the tenant loop pressure drop. Typical Pump Size 15 GPM @ 100’ TDH Tower Condenser Tenant Unit Tenant Unit Main Building Chiller