Modern Concepts for Control and Balancing Valves in HVAC Systems Dipl.-Ing. Thomas Leser Belimo Automation AG Hinwil, Switzerland

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1 Modern Concepts for Control and Balancing Valves in HVAC Systems Dipl.-Ing. Thomas Leser Belimo Automation AG Hinwil, Switzerland Limassol, Cyprus May 4, 2017

2 INDEX - TEASER 3 different Ways to control hydraulic Devices Traditional Approach Momentary State State of the Art Modern 2-Way Valves Concepts Pressure AND Temperature Independence Power Control Delta T Management Transparency Projects realized 2

3 Hydraulic Control Position control: The Control signal indicates a position. The valve operates pressure-dependent e.g. a conventional control valve. Flow control: The Control signal request a flow. Operation as a pressure-independent valve, Mechanical or Electrical principle. Power control: The control signal requests power output at the heat exchanger. The valve works temperature- and pressure-independent. 3

Power output at the coil is influenced by: Differential

4 The Challenge: Power Output is influenced by various Factors (1) Pressure dependent valve Control signal Power output Power output at the coil is influenced by: Differential pressure Coil characteristic Temperatures Valve opening Valve opening 4

5 Things to consider when using Pressure dependent Valves Pressure dependent valve????? VVV Thomas Leser,May 2017 Modern Valve Concepts 5

6 The Solution: Correct Distribution thanks to Dynamic Balancing Pressure independent valve VVV 6

7 The Challenge: Power Output is influenced by various Factors (2a) Pressure dependent valve Control signal Power output Power output at the coil is influenced by: Differential pressure Valve opening Valve opening Coil characteristic Temperatures Pressure independent valve Power output Coil characteristic Temperatures Control signal Mechanical: Via Diaphragm 7

8 The Challenge: Power Output is influenced by various Factors (2b) Pressure dependent valve Control signal Valve opening Valve opening Power output Power output at the coil is influenced by: Differential pressure Coil characteristic Temperatures Pressure independent valve Power output Coil characteristic Temperatures Control signal Electrical: via. Flow measurement 8

9 Valve Selection Some problems are not yet solved: How about if the coil was much too big, especially for partial loads? How about changing supply temperatures? How about coil degradation? 9

10 The solution: A Valve with immediate Power Control The Valve... Temperature and Pressure independent Valve provides direct power control The control signal requests a power output e.g. 7V = 958kW verifies and determines the power output at the heat exchanger in real-time Heat output / Cooling capacity 1400 kw 10 V 1400 kw 7 V 958 kw The power output is no longer influenced by changing water pressures by changing temperature and by characteristic of the heat exchanger 7 V 10 V Control Signal Y 10

11 The Solution: The Valve with immediate with Power Control Control signal Power output Power output at the coil is influenced by: Pressure dependent valve Differential pressure Coil characteristic Temperatures Valve opening Valve opening Power output Pressure independent valve Coil characteristic Temperatures Control signal Power output NOTHING Pressure and Temperature independent valve with power control Control signal 11

12 The Low Delta T Syndrome 12

13 Some of Low Delta-T causes Oversized pump and control valve Non-ideal circuit type Poor valve authority Missing hydraulic balancing Design change Coil degradation Thomas Leser May 2017 Modern Valve Concepts

14 Research & Development Project with MIT (2010) MIT s Charles Hayden Library 14

15 Components of an Energy Control System Balancing valve Feedback and Data Energy counter Control Valve & Actuator Regulation 15

16 Put it together and make it intelligent! Temperature measurement Return flow Energy consumption Power output Flow measurement Temperature measurement Supply flow Thomas Leser, May 2017 Modern Valve Concepts 16

17 Needful Components Setting Option with Display Real time monitoring Long term Data Logging Communication to BMS, WWW, Cloud Data Evaluation Tool DT-Management 17

18 Analysis of the recorded Data Project Data Power & DT Curve 18

19 Delta-T Power output LIM MAX Function of the "Delta-T Manager" (1) Heat exchanger saturation No NO increase Low Delta-T in power Syndrome output Assuring Reduced Delta-T Pumping Reduced more pumping water Increased Reduced efficiency desired level Thomas Leser, May 2017 Modern Valve Concepts 19

20 Delta-T Power output Function of the "Delta-T Manager" (2) Change in power characteristics! New status: desired level Max. performance of required Delta-T NO Low Delta-T Syndrome Assuring Delta-T Reduced pumping Increased efficiency Delta-T getting LOW! desired level 20

21 Delta T- Manager in Operation (Real Data) Valve Setpoint DT-Mgr. "ON" Valve Setpoint DT-Mgr. "OFF" ZONA DE DERROCHE DT DTM on/off 21

22 CASE STUDY Massachusetts Institute of Technology (MIT) Av. Delta T rose from 3.4 K => 6.7 K, chilled water flow was reduced by: 49% Annual savings: $1.5 million 23

23 CASE STUDY Massachusetts Institute of Technology (MIT) Building and Project Details 150,000 sq. ft. ( m 2 ) on 3 floors 6 AHUs provide majority of the cooling Results Aug 9 - Oct 9, 2010 LOW DT = 6.2 F (3.4 K) Aug 9 - Oct 9, 2011 DT = 12.1 F (6.7 K) 24

Reference Project Ludmillenstift - Retrofit, Germany Founded over 160 years ago, 26 medical departments / 400 beds. 1300 employees, incl.

24 Reference Project Ludmillenstift - Retrofit, Germany Founded over 160 years ago, 26 medical departments / 400 beds employees, incl. more than 130 doctors, care for in-patients and outpatients every year. Around 40 million euros will be invested in refurbishment work, modification and construction of new buildings by the end of

Situation at Ludmillenstift Before and After Distribution Circuit 1 (of 3) Complaints on a daily base Additional static/dynamic Balancing Valves Additional

to 90 C Putting the Pumps at full Speed Plans to install a new Boiler No comprehensive information about need, supply and consumption available Heating Delta T =>

25 Situation at Ludmillenstift Before and After Distribution Circuit 1 (of 3) Complaints on a daily base Additional static/dynamic Balancing Valves Additional circulation Pumps Hydraulic deflectors Rising the Supply Temp. to 90 C Putting the Pumps at full Speed Plans to install a new Boiler No comprehensive information about need, supply and consumption available Heating Delta T => below 4 K Increase of Operation Cost by ~ 150% Install new Valve Technology All new Balancing Valves removed All new circulation Pumps removed Lowering Supply Temperature to 75 C => Heating Delta T => 13-15K Overall transparency Thomas Leser, May 2017 Modern Valve Concepts 26

26 Hydraulic Setup Ludmillenstift, Germany Distributor circuit 1 (of 3) Thomas Leser, May 2017 Modern Valve Concepts 27

8 K) Results Delta T raised from 5.5 F (2.8 K) to 10.5 F (5.

27 Case Study University of Miami Hospital Building and Project Details Rosenstiel Building 11 AHUs 2600 Tons of Cooling Flow over 10,000 GPM Delta T = 5.5 F (2.8 K) Results Delta T raised from 5.5 F (2.8 K) to 10.5 F (5.8 K) Flow ~ 5600 GPM Estimated $66,000 Year Savings Estimated 2.9 years Payback Thomas Leser, May 2017 Modern Valve Concepts 28

28 Case Study Nanyang Technical University of Singapore Thomas Leser, May 2017 Modern Valve Concepts 29

29 Modern Valve Concepts for the HVAC Thank you very much for your attention 32

Written By : Simon Teo B. ENG (HONS)

Written By : Simon Teo B. ENG (HONS) The Ultimate Control Valves Used in Hydronic HVAC System FlowCon International pressure independent flow control valves () are changing the way control valves function