Green and sustainable HVAC System Peter Lau, Application Manager 1 Earthwise seminar 2010
Agenda Green HVAC system Sustainable HVAC system operation System specification 2
Green HVAC system 3
ASHRAE 90.1 Centrifugal Chiller 600 tons Once a year and path is chosen, both full and part load requirements must be met Performance includes drive losses Year/Path Full Load* (kw/ton) IPLV* (kw/ton) 90.1-2007/All 0.576 0.549 90.1-2010/Path A 0.570 0.539 90.1-2010/Path B 0.590 0.400 *For centrifugal chillers, requirements must be adjusted for non-standard conditions 4
ASHRAE 90.1 Helical Rotary Chiller 150 tons and < 300 tons Once a year and path is chosen, both full and part load requirements must be met Positive displacement chillers evaluated only at ARI Standard 550/590 standard conditions Year/Path Full Load (kw/ton) IPLV (kw/ton) 90.1-2007/All 0.717 0.627 90.1-2010/Path A 0.680 0.580 90.1-2010/Path B 0.718 0.540 5
Baseline performance D2.2.1 The simulation program shall be approved by the AHJ and shall, at a minimum, have the ability to explicitly model all of the following: a. 8760 hours per year b. Hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat setpoints, and HVAC system operation, defined separately for each day of the week and holidays c. Thermal mass effects d. Ten or more thermal zones e. Part-load performance curves for mechanical equipment f. Capacity and efficiency correction curves for mechanical heating and cooling equipment g. Air-side economizers with integrated control h. Inputs from on-site renewable energy systems (the renewable energy modeling program that is used must at a minimum be able to calculate monthly results) i. Baseline building design characteristics specified in Section D3. 6
Baseline performance D2.2.4 The simulation program shall be tested according to ANSI/ASHRAE Standard 140, and the results shall be furnished by the software provider. TRACE 700 Compliance with ANSI/ASHRAE Standard 140 7
Conventional vs Green system for 1000 tons 5 C delta T 8 C delta T Chilled water 0.15 lps/ton 0.10 lps/ton Condenser water 0.19 lps/ton 0.118 lps/ton 8
Baseline performance D3.1.3.10 Chilled-Water Pumps. The baseline building design pump power shall be 22 W/gpm (350 kw/1000 L/s). 9
Chilled Water Pump for 1000 tons flow rate pump head pump efficiency motor efficiency pump power Conventional 150 lps 36 meters 80 percent 95 percent 68 kw Green 100 lps 22 meters 80 percent 95 percent 27 kw 453 kw/1000 l/s 270 kw/1000 l/s Not meet D3.1.3.10 meet (350 kw/1000 L/s) 10
Baseline performance D3.1.3.11 Heat Rejection (Systems 7 and 8). The baseline building design condenser water pump power shall be 19 W/gpm (300 kw/1000 L/s). 11
Condenser Water Pump for 1000 tons Conventional Green flow rate pump head pump efficiency motor efficiency pump power 190 lps 27 meters 80 percent 95 percent 67 kw 118 lps 12 meters 80 percent 95 percent 20 kw 352 kw/1000 l/s 169 kw/1000 l/s Not meet D3.1.3.11 meet (300 kw/1000 L/s) 12
Cost more for Green HVAC System? Chiller Pump Cooling tower Fitting and valve 13
Case study of Green system 7-Storey Retail Shopping Mall 25-Storey Office Tower 3 x 800RT CVHG Chiller 2 x 400RT CVHE Chiller Location - Singapore 14
800RT Chillers Comparison Descriptions Tender Specifications 5.5 Deg C Delta T Low Flow Design: 8.9 Deg C Delta T Full Earthwise Design Chiller Model - CVHG 780 CVHG 780 CVHG 780 Min Refrigeration Capacity (Kw) 800RT 800RT 800RT 800RT Type of Compressor Hermatic Centrifugal Hermatic Centrifugal Hermatic Centrifugal Hermatic Centrifugal Min Chilled Water Flow rate (l/s) 122 121.8 75.3 75.3 Max Cooler Pressure Drop (Kpa) - 76.66 33.3 33.3 Entering Chilled Water Temp ( C) 12.2 12.2 14.9 14.9 Leaving Chilled Water Temp ( C) 6.7 6.7 6 6 Kw Input/Rton at Full Load based on 0.580 KW/RT 0.560 KW/RT 0.580 KW/RT 0.580 KW/RT 6.7 C Leaving Chilled water temp Min Condenser water flow rate (l/s) - 151.4 157.9 100.9 Max Pressure Drop thru' condenser (Kpa) - 78.93 66.29 61.89 Entering Condenser water temp ( C) 29.5 29.5 29.5 29.4 Leaving Condenser water temp ( C) 35 34.7 34.5 37.23 15
400RT Chillers Comparison Descriptions Tender Specifications 5.5 Deg C Delta T Low Flow Design: 8.9 Deg C Delta T Full Earthwise Design Chiller Model - CVHE 420 CVHE 420 CVHE 420 Min Refrigeration Capacity (Kw) 400RT 400RT 400RT 400RT Type of Compressor Hermatic Centrifugal Hermatic Centrifugal Hermatic Centrifugal Hermatic Centrifugal Min Chilled Water Flow rate (l/s) 61 60.9 37.6 37.6 Max Cooler Pressure Drop (Kpa) - 52.9 27.23 27.23 Entering Chilled Water Temp ( C) 12.2 14.9 14.9 Leaving Chilled Water Temp ( C) 6.7 6 6 Kw Input/Rton at Full Load based on 0.580 KW/RT 0.557 KW/RT 0.558 KW/RT 0.594 KW/RT 6.7 C Leaving Chilled water temp Min Condenser water flow rate (l/s) - 75.7 78.5 50.5 Max Pressure Drop thru' condenser (Kpa) - 50.48 90.17 41.96 Entering Condenser water temp ( C) 29.5 29.5 29.5 29.4 Leaving Condenser water temp ( C) 35 34.7 34.5 37.26 16
For 800RT Chiller Cooling Towers Comparison 152 L/s 35/29.5/28 5 cells, 27.5kw 15,790Kg 101 L/s 37.2/29.5/28 4 cells, 14.9kw 11,390Kg For 400RT Chiller 76 L/s 35/29.5/28 3 cells, 16.5kw 8,550Kg 50.5 L/s 37.3/29.5/28 2 cells, 11.0kw 5,710Kg 17
First Cost Savings Components Conventional System Green System Variants Chillers S$793,000 S$823,000 + S$30,000 Chilled Water & Condenser Pumps S$76,000 S$44,000 - S$32,000 Cooling Towers S$220,000 S$180,000 - S$40,000 Pipes & Fittings S$2,571,500 S$1,800,000 - S$771,500 Total Savings S$813,500!!! ( - 2.2 %) 18
Sustainable HVAC system operation Low cost in life span High system efficiency Trane control system 19
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Low cost in life span Reliable and efficient chiller Low operating cost Low maintenance cost Low refrigerant leakage cost 21
High system efficiency Green system Chiller Tower Optimization Variable primary flow system 22
Actual high system efficiency project TESCO Hypermarket in Bangkok, Thailand 3 x Trane Chillers Chilled water pump with Vsd Cooling tower with VSD fan Trane control system 23
Actual Plant Efficiency Comparison Conventional vs Green System System 1: Conventional System Chilled water temperature (7.2/12.7 C (45/55 F)) Chilled water flow rate (0.15 l/s (2.4 Gpm/Ton)) System 2: Green System Chilled water temperature (6.1/14.4 C, (43/58 F)) Chilled water flow rate (0.1 l/s, (1.6 Gpm/Ton)) Variable primary flow Chiller tower optimization 24
Zone Temperature (F) Zone temperature in occupied space ------ Conventional ----- Green ZONE TEMPERATURE AREA 1 STD Flow Cond. 45/55-28/4/07 (08:30-23:00) VS Low Flow Cond. 43/58-29/4/07(08:30-23:00) 87 86 85 Temperature difference of two systems less than 1.5 deg C 84 83 82 81 80 79 78 77 27.8 26.6 25.5 Zone 1 Temperature Conventional STD Flow 45/55 Green Zone 1 Temperature Low Flow 43/58 76 7:30 8:27 9:25 10:22 11:20 12:18 13:15 14:13 15:10 16:08 17:06 18:03 19:01 19:58 20:56 21:54 22:51 23:49 25 TIME
Efficiency (Kw/Tr) Overall plant and chiller efficiency 0.850 0.800 Overall Effciency (Kw/Tr) Analysis Between Chiller and Overall Plant for each System STD ------ Flow Conventional Cond. 45/55-28/4/07 (08:30-23:00) VS Low Flow Cond. -----43/58 Green - 29/4/07(08:30-23:00) Green system is 4% better in overall plant efficiency Overall plant efficiency Conventional AVG. Overall Plant Efficiency 0.748 Kw/Tr (Based on Stable Period 12-20) STD Flow 45/55 0.750 0.700 0.650 Overall plant efficiency Green AVG. Overall Plant Efficiency 0.713 Kw/Tr (Based on Stable Period 12-20) STD Flow 43/58 0.600 0.550 0.500 7:30 8:27 9:25 10:22 11:20 12:18 13:15 14:13 15:10 16:08 17:06 18:03 19:01 19:58 20:56 21:54 22:51 23:49 26 Chiller efficiency Conventional Chiller Efficiency (Kw/Tr) STD Flow 45/55 Chiller efficiency Efficiency (Kw/Tr) Green.. Low Flow 43/58 Time
Trane control system Chi 27
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System specification A = Cost of chiller B = At least 5 years energy cost based on running hours of chiller(s) for annual system cooling load profile C = At least five year chiller maintenance cost W = Adjusting factor 29
System specification 3 number of 800 tons chiller Operating cost based on office building system cooling load profile Chiller maintenance cost W = Adjusting factor 30
System specification HKD %/total Chiller cost 9,600,000 14.1% 5 years operating cost 57,600,000 84.6% 5 year maintenance cost 900,000 1.3% Total 68,100,000 100% 31
System specification HKD %/total Chiller cost 9,600,000 3.9% 20 years operating cost 230,400,000 93.7% 20 year maintenance cost with overhaul 6,000,000 2.4% Total 246,000,000 100% 32
System specification conventional First cost focus HKD % Adjusting factor HKD Chiller cost 9,600,000 14.1% 0% 9,600,000 5 years operating cost 57,600,000 84.6% 0% 0% 5 year maintenance cost 900,000 1.3% 0% 0% Total 68,100,000 9,600,000 33
System specification Green Reducing total cost 3,405,000 (5%) HKD % / total Adjusting factor HKD Adjusted % Chiller cost (8% better eff. Chiller) 5 years operating cost 5 year maintenance cost 9,600,000 14.1% +10% 10,995,000 17.0% 57,600,000 84.6% -8.4% 52,800,000 81.6% 900,000 1.3% 0% 900,000 1.4% Total 68,100,000 64,695,000-3,405,000 34
System specification Green and sustainable Reducing total cost 22,386,000 (9.1%) HKD % / total Adjusting factor HKD Adjusted % Chiller cost (10% better eff. Chiller) 20 years operating cost 20 year maintenance cost 9,600,000 3.9% +19.3% 11,454,000 ( efficiency) 5.1% 230,400,000 93.7% -9.0% 207,360,000 92.7% 6,000,000 2.4% -20% 4,800,000 (reliable) 2.1% Total 246,000,000 223,614,000-22,386,000 35
Case study - hypermarket stores in Asia Build, own and operating chiller plant Tender based on chiller cost, 5 years maintenance cost and 5 years operating cost Over 200 chillers tender based on 5 years total cost 36
Take away Green system High system efficiency Low cost in life span Trane control system Energy analysis (Trace 700 ) System specification 37
Question? 38