ACMV Systems.pdf

Induction Course for new M&E Engineers4 – 6 March 2013 Air Conditioning and Mechanical Ventilation Systems Ir. Ng Yong Kong Managing Director NYK Engineering & Trading Sdn Bhd Induction Course for new M & E Engineers Air-Conditioning and Mechanical Ventilation 6th March 2013 Ir. NG YONG KONG, P.Eng., GBIF, MASHRAE Email: [email protected] Tel: +6012 – 201 9319 1.ASHRAE Handbook – SI and Imperial Units a.Fundamentals 2013 b.HVAC Systems and Equipment 2012 c.HVAC Applications 2011 d.Refrigeration 2010 2. Air Conditioning System Design - CARRIER 3. Handbook of A/C Design – TRANE 4. CIBSE 5. MS 1525:2007 COP on Energy Efficiency and Use of Renewable Energy for Non-Residential Buildings ( 1st Revision) 5. Uniform Building By – Laws 1984 (UBBL) 6. Guide to Fire Protection in Malaysia INDUCTION COURSE IN AIR-CONDITIONING 1) 2) 3) 4) 5) 6) 7) 8) 9) INTRODUCTION TO AIR-CONDITIONING PRINCIPLES OF REFRIGERATION PSYCHROMETRICS COOLING LOAD ESTIMATION & SOFTWARE REFRIGERANT ISSUE TYPES OF AIR CONDITIONING SYSTEMS AHRI 550/590 or MS2449 FOR CHILLERS MS1525:2007 Green Building Index ( GBI ) . Main components that determine comfort : • • • • Climatic conditions Outdoor environment Indoor environment Activities & clothing .) Introduction to Air Conditioning What is Comfort? Definition: A State of Ease and Contentment” • “A satisfying and enjoyable experience” The feeling of comfort is clearly subjective.1. Comfort Requirements • • • • • • • • Temperature Humidity Air movement Fresh air Clean air Noise level Lighting Furniture and work surfaces . ASHRAE Comfort Zone . ASHRAE Standard 55-2010 Specifies conditions likely to be thermally acceptable to at least 80% of the adult occupants in a space . . Design to ASHRAE 55-2010 : Thermal Environmental Conditions for Human Occupancy in conjunction relevant localised parameters as listed in MS 1525:2007 Specifies Conditions likely to be thermally acceptable to at least 80% of the adult occupants in a space 6 Primary factors that must be addressed when defining conditions for thermal comfort are: 1.) Radiant temperature 5.) Metabolic rate 2.) Air speed 6.) Air temperature 4.) Humidity .) Clothing insulation 3. .2. Principles of Refrigeration • The science of refrigeration is based upon the fact that a liquid can be vaporised at any desired temperature by changing the pressure on it. • The large quantities of heat is absorbed when liquid is evaporated (Changed to vapour). What is a Refrigerant? A refrigerant is a fluid that absorbs heat and changes from vapor to liquid phase at reasonable pressures and temperatures as encountered in mechanical refrigeration. • Liquids boiling at low temperatures (Refrigerants) are the most desirable medium for removing heat. PRESSURE psia °F Water -40 HCFC-22 HFC-410A 0.26 26 0 0.73 40 0.77 16. pressure psia HFC-134a .6 130 2.6 0.696 *CP *CP 587.225 311.28 132 49.20 X X *Critical Point.80 X 188.50 78.70 567.122 100 CO2 Propane 7.60 500 213.0185 38.2.4 82.80 38.950 210.43 145.3 212 14.70 340 138.40 X 273.00186 15.What is a Refrigerant .1 64 21.62 305. Four Laws of System Operation 1. Heat only moves from a higher temperature to a lower temperature 2. Fluid flow only occurs if a pressure difference exists . A large amount of energy is required to change the state of matter 3. The temperature and energy required to change state are a function of pressure 4. Three Types of Heat Transfer Conduction Conduction – Transfer by contact Convection – May be natural or forced transfer by density currents and fluid motion Radiation – Transfer by electromagnetic waves Mechanical refrigeration uses the first two. . 000 Btu/Hr.517 kWr 1 F RISE 1 lb 1 Btu . = 3.Sensible Heat Btu is the heat energy necessary to change one pound of water by 1° F Btu – British thermal unit 1 ton = 12. Latent Heat Total Heat = Sensible Heat + Latent Heat 212° F 212° F Not measured on a thermometer Change of State Section 2 – Basic Principles . it evaporates and refrigeration can be obtained. • When the liquid refrigerants are allowed to expose to the atmosphere. compressor and condenser.Refrigeration Cycle • The refrigeration can be obtained by use of the refrigerants. • To make use of the vaporised refrigerant over and over again it is necessary to use the devices like evaporator. . Heat rejecting section 4. Vapor pump . Heat absorbing section 2. Pressure/ flow control valve 1.Four Components Are Required 3. . 7° F db / 57.3° F wb Evaporator Evaporator Compressor Compressor 45° F 90.7 psia 120° F 274.8 psia Every system has four basic components 55° F 90.Basic System Components Condenser Air out: 115° F db 108° F 274.7 psia SCT SDT Air in: 95° F SST Air out: 59.8 psia SET Air in: 80° F db / 67° F wb Condenser Rejects the heat from the load and system losses Highly superheated refrigerant condenses in the tubes as heat load is rejected and changes back to a liquid and is subcooled . Psychrometrics .3. Objectives • Understand the properties of air and water vapor mixtures • Build the psychrometric chart • Use the psychrometric chart to determine the properties of an air/water vapor mixture • Use the psychrometric chart to understand the basic air conditioning processes • Understand how the processes can be combined into a system using a system plot diagram and psychrometric chart Section 1 – Introduction . Determine the sensible and total cooling load the unit should provide 5.Why Study Psychrometrics? 1. Calculate the required airflow to the space and for the equipment 4. Determine the coil depth and temperature to meet the design load conditions Brooklyn Printing Plant Section 1 – Introduction . Determine the temperature at which condensation will occur in walls or on a duct 2. Find all the properties of air by knowing two conditions 3. Dry-Bulb Thermometer The temperature of air as measured by a thermometer with a dry sensing bulb . at which water will evaporate into the air sample. . Physically…the temp. of air when measured by a thermometer with a wetted wick over the sensing bulb.Wet-Bulb Thermometer The temp. Sling Psychrometer • • • • Avoid adverse conditions that can affect reading Moisten wick before procedure Rotate device at least 2 minutes Read device immediately after rotation Section 3 – Building the Psychrometric Chart Water Vapor in Air Water Vapor Dry Air Air + Vapor Mechanical Mixture Relative Humidity ( RH ) 50% 100% (saturated) If RH of the air is 50%, it contains one-half the amount of moisture possible at the existing dry-bulb temperature. .Relative Humidity Relative Humidity = Amount of moisture that a given amount of air is holding Amount of moisture that a given amount of air can hold At the same dry-bulb temperature. The amount of water vapour in the air. compared to it’s maximum capacity at that dry bulb temperature. Dry Bulb Temperature Scale wb dp °F db °F Section 3 – Building the Psychrometric Chart . Dew Point Example 95° F db 100 gr 100 gr wb dp °F db °F 55° 67° 95° . Condensation Occurs at Dew Point © American Standard Inc. 1999 Air Conditioning Clinic TRG-TRC001-EN . 132 gr 45% wb dp °F db °F 75° 60 gr .Relative Humidity Lines Relative 60  45% Humidity  132 Approx. 5 Btu/lb wb dp °F db °F .Enthalpy Scale hs = Enthalpy at saturation hs = 27. Psychrometric Chart Enthalpy Specific Volume Relative Humidity Wet Bulb Temperature Dew Point Temperature Specific Humidity wb dp °F db °F Dry Bulb Temperature . Heating and Humidification 8. Sensible Heating Sensible Cooling Humidification Dehumidification Cooling and Humidification (Evaporative Cooling) 6. Heating and Dehumidification wb dp °F db °F . 5. 2.Air Conditioning Processes 1. 3. Cooling and Dehumidification 7. 4. 10  cfm  t db wb dp gr - Changes Changes Constant Constant 68% rh 24% rh COOLING 52 gr HEATING wb dp °F 90 – 60 = 30 t db °F 60° 90° Sensible Heat Change .Sensible Heat qs  1. Latent Heat q l  0.69  cfm   grains Changes Changes Changes Constant 68% rh Evaporation - Condensation wb dp gr db wb dp °F db °F 75° 24% rh  grains 89 – 30 = 60 89 gr Latent Heat Change 30 gr . Total Heat qt  qs  ql Grains t Evaporation wb dp °F Condensation Cooling Heating db °F 75° 95° Sensible Heat Change 89 gr Latent Heat Change 30 gr . 0 wb dp °F db °F 55° 75° .Using Enthalpy to Determine Total Heat Removed Latent Heat 1.7 Sensible Heat 5. 5  cfm  h Where: GTH = 4.5 = cfm = h = Grand Total Heat Constant cubic feet per minute Difference in enthalpy from air entering to air leaving conditions .Total Capacity or Load Formula GTH = 4. Cooling Coils Face Area = Length  Height Length Height Velocity cfm / face area Rows Fins Refrigerant Temperature . ASHRAE Comfort Zone . roof. glass. wall. partitions from non conditioned spaces.Location/altitude/ orientation • Transmission through Building Components walls. • Solar Radiations on . . roofs.glass. ceilings.) Cooling Load Estimation To design the effective HVAC design. etc. Cooling Load Components: .4. doors and floors. the analysis of heat load is carried out. • Latent and Sensible heat losses from people.Human Comfort . • Lighting and ballasts. • Appliances and equipment in the conditioned space. • Ducts and motor heat gain from cooling system itself. • Infiltration of outdoor air. .Design • Ventilation Requirements. . . Building code requirements Extract from Third Schedule (By-law 41) . .1 is the Leading Standard adopted by most Local Authorities and HVAC Engineers in the world.1-2010 Ventilation For Acceptable For Indoor Air Quality Ventilation is the key to Sustainable IAQ and ASHRAE Std 62.ASHRAE STD 62. .) Ventilation Rate Procedure ( VRP ) – is a prescriptive procedure with a table of minimum required outdoor airflow rates per occupant for a variety of non- residential occupancies. adjusted to reflect the air distribution system used. The airflow rate per square foot of building floor area is basedon the design occupancy density and the required flow rate per person.Acceptable Indoor Air Quality is defined as air in which there are no known Contaminants at harmful Concentrations as determined by Cognizant Authorities and with which a substantial majority ( 80% or more ) of the people exposed do not express dissatisfaction. 1. ) Ventilation Rate Procedure ( VRP ) Vbz = Rp.i.1-2007 – Ventilation For Acceptable Indoor Air Quality 1.Az Where Vbz = Design outdoor airflow required in the breathing zone of the occupied space or spaces in a zone. Rp = outdoor airflow rate required per person as determined from Table 6-1 Ra = outdoor airflow rate required per unit area as determined from Table 6-1 .ASHRAE Std 62.Pz + Ra.e the breathing zone outdoor air flow Az = Zone floor area: the net occupiable floor area of the zone m2 ( ft2) Pz = zone population: the largest number of people expected to occupy the zone during typical usage. ASHRAE Std 62.1-2010 – Ventilation For Acceptable Indoor Air Quality 1.) Ventilation Rate Procedure ( VRP ) 2.) Indoor Air Quality Procedure ( IAQ ) - air filtration/purification to remove some or all of the contaminants of concern can be part of the system. TABLE 6-1 MINIMUM VENTILATION RATES IN BREATHING ZONE People Outdoor Area Outdoor Occupancy Air Rate Air Rate Default Values Occupant Density Combined Outdoor Air Rate Category Rp Ra cfm/ person L/s person cfm/ft ² L/s m² Office Space 5 2.5 0.06 Reception areas 5 2.5 0.06 #1000 ft² or #100 m² cfm/ person L/s person 0.3 5 17 8.5 0.3 30 7 3.5 Office Buildings TABLE 6-1 MINIMUM VENTILATION RATES IN BREATHING ZONE Hotels, Motels, Resort, Dormitories Bedroom / living room 5 2.5 0.06 0.3 10 11 5.5 Barracks sleeping areas 5 2.5 0.06 0.3 20 8 4.0 Laundry rooms, central 5 2.5 0.12 0.6 10 17 8.5 Laundry rooms within 5 2.5 0.12 0.6 10 17 8.5 7.5 3.8 0.06 0.3 30 10 4.8 5 2.5 0.06 0.3 120 6 2.8 dwelling units Lobbies / pre-function Multipurpose assembly 26ºC (73.8°F ) 22ºC 55% .4 – 78.2ºC ( 92°F/ 81°F ) .3ºC / 27.15 m/s – 0.MS1525-2007 Air Conditioning and Mechanical Ventilation (ACMV) System a) b) c) d) e) a) Indoor Design Condition Recommended Design DB Temperature Minimum DB Temperature Recommended Design RH Recommended Air Movement Maximum Air Movement 23 .50m/s 0.70% 0.7 m/s Outdoor Design Conditions Recommended Outdoor Design Conditions DB / WB 33. ASHRAE Comfort Zone . Type of Refrigerants CFC HCFC HFC •R-11 •R-12 •R-13 •R-500 •R-502 •R-503 •R-22 •R-123 •R-401A •R-401B •R-402A •R-402B •R-408A •R-409A •R-134a •R404A •R-407C •R-410A •R-507 HFO HFO 1234fy . 5.) Refrigerant IssueEnvironmental Impact • ODP: Ozone Depletion Potential • GWP: Global Warming Potential • Climate Change . ) TYPES OF AIR CONDITIONING SYSTEMS WRAC • WRACs are factory-made assemblies that normally include an evaporator or cooling coil and a compressor-condenser combination • Room Air Conditioners are encased assemblies designed primarily for mounting in a window or through a wall and are often called Window Room Air Conditioners ( WRAC ). .7. Window Room Air Conditioner Window room air conditioner . . . Air Cool Split Units • A Unitary Air Conditioner with more than one factory-made assembly is commonly called a split system. they are known as the Air Cooled Split Units. • It basically comprises an indoor unit with the evaporator and blower and an outdoor unit with the compressor. condenser coil and fan coupled with refrigeration piping. As a whole. • The indoor units is often known as Fan Coil Units ( FCUs )and the outdoor units known as Condensing Units. (ACSUs) . Air Cooled Split Units Warm air (recirculating) Fan Coil Unit Cool air Outdoor air Condensing Unit .3. Wall Mounted Floor Standing Cassette Ceiling Exposed . The outdoor unit is basically the same construction for all the various types of indoor units.3. The difference lies in the type of indoor unit.Air Cooled Split Units (ACSUs) Both indoor and outdoor units are housed in robust casings. 65 Most aesthetic Floor Standing 7.26-17.26-14.03-14.60 Can be Floor mounted . Air Cooled Split Units Common Fan Coil Units Type Typical Cooling Capacity (kWr) Remark Wall mounted 2.64-7.65 Not so Common here Under Ceiling Exposed 5.03 Most common Ceiling cassette 5.3. Manufacturers recommend a Maximum Piping length of 7 to 15 m and maximum elevation between indoor and outdoor unit of 5 to 7 m.3. Air Cooled Split Units The installation of an Air Cooled Split Unit is basically the same with the outdoor and indoor units connected with refrigerating piping called Suction and Liquid line. . ) Air Cooled Split Units Many Business Establishments are housed in Small Premises using ACSUs. Office Restaurant .4b. ) ACSUs Application Shop Office .4b. Advantages • • • • • Low first cost Flexibilities Easy to maintain Short lead time Ex Stock Other Systems • Low Efficiency • No Fresh Air • Potential IAQ issues . ACSUs : Fresh Air Intake ? The wall mounted and under ceiling split system has no provision for intake of outdoor air and/or exhaust of stale room air. . filtered and recirculated. Room air is just .3. 3. A fan may be added if the intake is far away. .) Air Cooled Split Units The Ceiling Cassette Split System has a knockout in the casing that allows outdoor fresh air to be introduced. WC Packaged .Typ. Capacity range from 2.Floor Standing Typical kw / ton around 1.0. Capacity range from 20 – 100 Hp .5.Typ.WC Splits .Ducted/Under ceiling .2 kw/ton .1.0 – 6 Hp . Water-cooled Splits/Packaged Units . 6. Variable Refrigerant System       On a single refrigerant pipe. . many indoor units can be connected. Advantages • Flexibilities • Better RH than ACSUs • Space Saving • Better EE than ACSUs Others Systems • Moderate Energy Efficiency Compared to CHWS • Potential IAQ Problem . 3°C) 97°F (36.1°C) condenser 55°F (12.6°C) cooling tower pump Airside Loop (AHU & Air Duct) Chilled Water Loop (CHWP.0°C)(37.7°C) 41°F 100°F (5.2°C) 50°F 110°F (10°C)(43.7°C) 54°F (12. Piping & Cooling Coil) Refrigeration Loop (Water-cooled Chiller) Condenser Water Loop (CWP.8°C) 44°F (6. Piping & Cooling Tower) .8°C) 87°F (30.Chilled Water System control valve 80°F (26. Packaged Air-Cooled Chiller compressor evaporator Airside Loop (AHU & Air Duct) Chilled Water Loop (CHWP. Piping & Cooling Coil) expansion device Refrigeration Loop (Air-cooled Chiller) air-cooled condenser . 7°C] 54°F [12.Conventional chilled water system 44°F [6.2°C] 3-way valve . Primary-Secondary Configuration primary pumps Variable secondary pump production loop distribution loop two-way valve . Variable-Primary-Flow Systems Variable-flow pumps check valves control valve two-way valve optional bypass with three-way valve . Constant Primary Flow / Variable Secondary Flow Chilled Water System Secondary Pumps (Variable Speed) Chiller Chiller (Constant Flow) (Constant Flow) Decoupling Bypass Isolation Valves Load Load (Variable Flow) (Variable Flow) P Control Valves Primary Pumps (Constant Speed) 80 . Type of Chiller Compressors (Hermetic or Semi-Hermetic) Scroll Reciprocating Helical-Rotary Screw Centrifugal Compressor . 1 – 1. Commercial.3 kw/ton • Applications : • Retail. Industrial & Government Scroll & Screw & some using Reciprocating .Air-cooled Chiller • 20 – 100RT for Scroll • 70 – 500 RT for Screw • Typical Efficiency range 1. 7 kw/ton • Applications : • Retail. Buildings Scroll & Screw & some using Reciprocating .Water-cooled Chiller • 20 – 100RT for Scroll • 70 – 400RT for Screw • 100 – 2500 RT • Typical Efficiency range 0.5 – 0. Commercial. Industrial & Govt. which is similar to a car moving downhill. In temperate climates. the WB drops significantly. thus the condenser water supply will also drop. PTM .thus. Source: Malaysian Industrial Energy Audit Guidelines – MIEEIP. the refrigerant will work more effectively during those periods of low wet bulb temperature. The new “lift” for the refrigerant is achieved by reducing the compressor speed. the chiller compressors will overspeed During low wetbulb temperature the lift changes.Centrifugal Malaysian tropical climate has a near constant wet bulb temp thus VSDs do not save a huge amount of energy. thus causing the compressor to overspeed.at low CWS.• Avoid VSD Chillers . Variable Speed Chillers – Screw or Centrifugal Good variable Part Load Value for 4-season areas. Low Ambient Need to carefully Evaluate Benefits. . DX versus Chilled Water Major factors Affecting the Decision • • • • • • • • • Installed Cost Energy Consumption Type of Application Space Requirements Building Aesthetics System Capacity Centralized Maintenance Stability of Control Redundancy . 9 .3 0.20 years 20 .0 .30 years System EE kW/ton 1.1.2.1.500RT+ .Air-Cooled vs Water-Cooled Air-cooled Water-cooled Life Span 15 .500RT 50 .1 Maintenance Lower Higher Noise Containment Open Enclosed Space Requirement Less More Cost Lower Higher Capacity Range 3 . Approx.Typical Energy Usage in a Commercial Building in Hot/Humid climates DHW 12% Lighting 10% Other Equipment 15% Variable Frequency Drive (VFD)/ Variable Speed Drive (VSD)/ Speed Controller -Improve comfort levels -Reduce operating costs. 60% .Air Conditioning Plant AHU/FCU 24% Central Plant 39% . Chilled Water System: Direct or Reverse Return . INDEPENDENT CONTROL VALVE Design • Pressure Independent Control • Automatic balancing • Commissioning Save installation space & time Save commissioning time & balancing Eliminate error .DYNAMIC BALANCING CONTROL VALVE PICV – PRES.DBCV . Illuminated enclosure GREEN: normal RED: fault . Air Distribution System Methods of Air Flow Control Air flow : •Outlet dampers •Inlet guide vanes •Variable pitch fan •Variable Speed Drive(VSD/VFD) . Water Distribution System Methods of Water Flow Control Water Flow Centrifugal pumps : •Bypass valve (three way) •Throttling valve (two way) •Trim Impeller (irreversible) •Variable Speed Drive (VSD) . g 80% speed Input power = (0.Fans and Centrifugal Pumps Fundamentals Affinity Laws Air Flow2 Fan Speed2 = Air Flow1 Fan Speed1 – Air/Water flow is proportional to Fan/Pump Speed Static Pressure2 Static Pressure1 = Air Flow2 Air Flow1 2 – Static Pressure is proportional to (Fan/Pump Speed)2 Input Power2 Input Power1 = Air Flow2 Air Flow1 3 – Input Power is proportional to (Fan/Pump Speed)3 w/o system effect e.8x0.51 or 51% .8) = 0.8x0. Constant Air Volume ii.Air Distribution System – Supply Fan Basics •There are two types of air distribution systems i.)CAV .)VAV – Variable Air Volume . • If location being served requires less cooling. the supply air temperature remain the same but the total volume of supply air remains the same as if full cooling is required .CAV – Constant Air Volume • In CAV systems. thermal comfort is achieved by delivering a constant volume of supply air. Supply Fan Basics • There are two types of air distribution systems – Variable Air Volume – Constant Air Volume • VFDs/VSDs are not only applied to VAV systems but can also be incorporated into CAV systems. Supply Fan .Air Distribution System VFD/VSD Application . . for large single zone CAV systems.Air Distribution System CAV Supply Fan Basics Conditioned Space • No method of controlling air flow is provided • The conditioned space receives “Design” air flow at all times T Supply Fan • The chilled water valves are controlled by space temperature • However. it’s possible to convert them to single zone VAV systems Sensor may be in return air duct. VAV – Variable Air Volume • To maintain thermally comfortable conditions. VAV systems utilize a resetable constant temperature of the delivered air to most locations. . • Varying the air flow is controlled by using a VFD/VSD in the fan motor. while varying the quantity of air delivered to the individual zones in the building. AHU 8. Supply Fan VFD 7. Duct Static Pressure Sensor 6. Zone Thermostat 3.VAV . VAV Box 2. Return Grille 5. Air Diffuser 4.Variable Air Volume System Components: 1. Supply Duct Section 1 – Introduction Zone 1 Zone 2 Zone 3 Zone 4 . g : Hotel Lobby.Air Distribution System Why put a VFD/VSD on CAV SYSTEM • Oversized systems Variable Occupancy Profile E.. etc. • Eliminate over capacity => energy saving. Office or Lift Lobby.Vary from 70-100% . => Lower Acoustic Noise => easier balancing Better temperature control maintain minimum airflow . conference hall. Large Single Zone office. Cineplex. eg 80% Input Power = (0.8 x 0.Air Distribution System CAV to — Single Zone VAV using VFD/VSD • VFD controls air flow just as VAV boxes would • Coils control supply air temperature Supply Fan • Works for large.8) = 0.51 or 51% .8 x 0. single-zone systems Maintain minimum airflow typically 70% and vary between 70-100% based on temp. Air quality or CO2 inputs Input Power2 Air Flow2 3 = Input Power1 Air Flow1 Input Power is proportional to (Fan Speed) – w/o system effect Supply Fan Drive Conditioned Space T T Sensor may be in return air duct. Heating and Refrigeration Institute) AHRI STD. 551/591–2011 .Chiller Standard Performance Rating Standard ( Air-Conditioning. MS 1525:2007 Code of Practice on Energy Efficiency and Use of Renewable Energy for NonResidential Buildings (1st Revision) . 36 Section 8.1 Kw/Ton at 1.) MS 1525:2007 Code of Practice on Energy Efficiency and Use of Renewable Energy for Non-Residential Buildings (1st Revision) Pg.Chillers Standard Rating Conditions 1.) 100% or Full load 2.11.) Part Load . Chiller Standard Performance Rating Standard Eurovent JIS GB MS2449:2012 . MS 2449:2012 Performance rating of waterchilling packages using the vapor compression cycle . ) Hermetic & Open type.000 Volts.) Centrifugal & Screw Chillers with Continous Loading 2. 3.) Voltages up to 5. 4.000 tons (703 – 3. .Included in AHRI STD Certification Program for 50 Hz Electrical Power 1.517 KW ) at Standard ARI Rating Conditions. electric motor driven.) Rated 200 – 1. 2.) Air-Cooled Chillers.Excluded in AHRI STD Certification Program for 50 Hz Electrical Power 1. 6.) Chillers with Voltages above 5000 volts. 8.) Chillers with motors not supplied with the unit by the manufacturer. .) Scroll & Reciprocating compressor chillers with step unloading.) Chillers below 200 tons and above 1000 tons. 5.)Evaporatively Cooled Chillers.) Chillers powered by other than electric motor drives. 4. 7. 3.) Condenserless Chillers. 1 ) Percent Load Weighting of Part Load Points 1992 Std 1998 Std 2003 Std 100% 17% 1% 1% 75% 39% 42% 42% 50% 33% 45% 45% 25% 11% 12% 12% .6. ft²°F/Btu) or (m².°c/w) 1992 1998  Cooler 0.00025 0.00025 0.0001  Condenser 0.00025 A = kw/ton at 100% Load C = kw/ton at 50% Load B = kw/ton at 75% Load D = kw/ton at 25% Load .6.2) Fouling factors (h. TO USE FOR PART LOAD PERFORMANCE FROM 100% DOWN TO 0% 7.) Entering Condenser Water Temp. commonly used in Malaysia to evaluate Part Load Performance: Percent Load (1) (2) °F °F F 100% 85 87 87 75% 75 87 85.WHAT TEMP.5 25% 65 87 81.75 0% 65 87 80 .25 50% 65 87 83. Flow Rates and Temperatures 95°F 44°F [35°C] 44°F 97°F [6.7°C [6.7°C] [36.1°C] 85°F 87°F [29.4°C] [30.6°C] ARI conditions Malaysia Conditions 54°F 54°F [12.2°C] [12.2°C] evaporator flow rate condenser flow rate 2.4 gpm/ton [0.043 L/s/kW] 3.0 gpm/ton [0.054 L/s/kW] evaporator flow rate condenser flow rate 2.4 gpm/ton [0.043 L/s/kW] 3.0 gpm/ton [0.054 L/s/kW] Typical Schematic of Chilled Water HVAC System Condenser water makeup CHILLED WATER F FCU COOLING TOWERS F F T T F 15ºC AHU T T MAIN RISER FEED 6ºC 15ºC AHU AHU RETURN AIR FAN F F T MAIN RISER RETURN 9 - 12 ºC F T 15ºC By Air T By Refrigerant F PRIMARY CHILLED WATER PUMPS T CONDENSER WATER 35ºC By Air F F F F CONDENSER CHILLER 3 SECONDARY CHILLED WATER PUMPS CHILLER 2 15ºC CHILLER 1 T EVAPORATOR F CONDENSER WATER PUMPS RETURN CONDENSER WATER 30ºC By Water The importance of controlling the flow of air and water in HVAC systems Chillers – Flow Rates and Temperatures Why use •10 °F •12 °F •14 °F 10°F and how much above can we go ? = 2.4 USgpm/RT = 2.0 USgpm/RT = 1.7 USgpm/RT Btuh = 500 x Q(USgpm) x ΔT (deg F) kWR = 4.187 x Q(l/s) x Δ T (deg C) Saves Energy Equipment Rating Stds shouldn’t restrict us from designing more efficient CHW 1-115 system 12 A B C D Where : A = KW/Ton at 100% .42 + 0.01 + 0.45 + 0. D = KW/Ton at 25 % 25% Load 12% 45% 100% Load 1% 50% Load 75% Load 42% 1-116 . B = KW/Ton at 75 % C = KW/Ton at 50 % .Chiller Part Load Performance IPLV / NPLV =____________1____________ 0. (With or Without diversity factor) – Part Load.Design Based On Consultant Calculation.Full Load Vs Part Load • Both FullPart and Part Load Efficiency can be important.May be running most of the time? The arts and sciences of HVAC based on experience . • Full Load. . MS 1525:2007 Code of Practice on Energy Efficiency and Use of Renewable Energy for NonResidential Buildings (1st Revision) . 2 8.5 8. Air-conditioning and mechanical ventilation (ACMV) system 8.8 Load calculations System and equipment sizing Separate air distribution systems Controls Piping insulation Air handling duct system insulation Duct construction Balancing .4 8.7 8.1 8.8.6 8.3 8. 10 8.13 System testing and commissioning 8.15 Preventive maintenance .8.9 8.12 ACMV systems ACMV system equipment ACMV system components ACMV system equipment/component – heat operated (absorption). cooling mode 8.14 Operation and maintenance (O&M) manual and as-built drawings 8.11 8. Air-conditioning and mechanical ventilation (ACMV) system 8. .1.8. or other equivalent publications.1 Load calculations 8.1 Calculation procedures Cooling system design loads for the purpose of sizing systems and equipment should be determined in accordance with the procedures described in the latest edition of the ASHRAE Handbook. . room comfort condition should consider the following three (3) main factors: • dry bulb temperature. For the purpose of engineering design.1. mean radiant temperature.2 Indoor design conditions Room comfort condition is dependent on various factors including air temperature. clothing. humidity.8. and • air movement (air velocity) . • relative humidity. metabolic rate and air movement preference of the occupant. if required because of special occupancy or process requirements or source control of air contamination or Indoor Air Quality consideration.1.8. Exception: Outdoor air quantities may exceed those shown. .4 Ventilation Outdoor air-ventilation rates should comply with Third Schedule (By Law 41) Article 12(1) of Uniform Building By Laws. 1984. multi compressors etc so as not to diminish the equipment/system efficiency when operating at varying loads. if incorporated into the sizing of the duty equipment. efficient unloading devices. Redundancy in capacity of equipment.2.2 System and equipment sizing 8. high efficiency motor. consistent with available equipment capacity.1 above.1 Air conditioning systems and equipment shall be sized to provide no more than the space and system loads calculated in accordance with 8.8. . should include efficiency devices such as variable speed drive. 000 kWr.2 Where chillers are used and when the design load is greater than 1.2. 8. a minimum of either two chillers or a single multi-compressor chiller should be provided to meet the required load.2. such as multiple chillers. with combined capacities exceeding the design load may be specified to operate concurrently only if controls are provided which sequence or otherwise optimally control the operation of each unit based on the required cooling load.8.3 Multiple units of the same equipment type. . 2. Each thermostat should be capable of being set by adjustment or selection of sensors over a minimum range of between 22 C to 27 C.8.4.4 Controls 8. .1 Temperature control Each system should be provided with at least one thermostat for the regulation of temperature.4. Multi-stage thermostat should be provided for equipment exceeding 35/65 kWr in conjunction with 8. 2 Humidity control In a system requiring moisture removal to maintain specific selected relative humidity in spaces or zones. .4.8. no new source of energy (such as electric reheat) should be used to produce a space relative humidity below 70 % for comfort cooling purposes. heat pipe or any other energy recovery technology. . Examples include the use of condenser water for reheat.3 Energy Recovery It is recommended that consideration be given to the use of recovery systems which will conserve energy (provided the amount expended is less than the amount recovered) when the energy transfer potential and the operating hours are considered.8. desuperheater heat reclaim.4. Recovered energy in excess of the new source of energy expended in the recovery process may be used for control of temperature and humidity. heat recovery wheel. thermostat control. .4. duty cycle programming and CO/CO2 sensor control.8. Examples of such devices would include timer switch control.5 Mechanical ventilation control Each mechanical ventilation system (supply and/or exhaust) should be equipped with a readily accessible switch or other means for shut-off or volume reduction when ventilation is not required. the power required by the motor for the entire fan system at design conditions should not exceed 0.4. .45 W per m3/h of air flowrate.6 Fan System Efficiency For fan system with air flowrate exceeding 17000 m3/h and operating for more than 750 hours a year.8. with the rate of leakage not to exceed the maximum rate specified.7 Duct construction All ductwork should be constructed and erected in accordance with HVAC Duct Construction Standards Metal and Flexible published by SMACNA or any other equivalent duct construction standards.1 High-pressure and medium-pressure ducts should be leak tested in accordance with HVAC Air Duct Leakage Test Manual published by SMACNA or any other equivalent standards. .8. 8.7. temperature and pressure test connections and balancing valves. .8 Balancing The system design should provide means for balancing the air and water system such as but not limited to dampers.8. aircooling with controlled temperature and dehumidification. air-cleaning. and the refrigerant condenser may be air. in one (single package) or more (split system) factory assembled packages. water or evaporativelycooled. The cooling function may be either electrically or heat operated.8. . means for air-circulation.10 ACMV system equipment • ACMV system equipment provides. the separate packages should be designed by the manufacturer to be used together. • Where the equipment is provided in more than one package. Launched July 2007 . • Hydraulic system balancing should be accomplished in a manner to minimise throttling losses and then the pump impeller should be trimmed or pump speed should be adjusted to meet design flow conditions. . • ACMV control systems should be tested to assure that control elements are calibrated. adjusted and in proper working condition.13 System testing & commissioning • Air system balancing should be accomplished in a manner to minimise throttling losses and then fan speed shall be adjusted to meet design flow conditions.8. filters and piping.8. condensers. controls. pumps. . air handlers.15 Preventive Maintenance • The owner should implement preventive maintenance system and schedule periodic maintenance on all the critical items of air-conditioning systems such as compressors. cooling towers. AHU Room with Acoustical Problems . g. decorative fountains. .Found in any aquatic environment e. whirlpool spas. fire sprinklers systems.Bacteria – Legionella pneumophilia . showers. humidifies. Cooling towers.Respiratory disease . evaporative condensers.What is Legionnaires’ Disease? . .Sign and Symptoms of Legionnaires’ Disease .5 -15% of known cases have been fatal .5 deg C or about 104-105 deg. vomiting and diarrhea may occur . pain in the muscles and a general feeling un-wellness.F) and shaking chills.Dry coughing and chest pain might occur . .Nausea.High fever (up to 40°-40.Usually begins with a headache. . Those who maintain cooling towers in air conditioning systems .Who is more likely to get Legionnaires’ disease? .Those who smoke tobacco or have chronic lung disease .Middle aged or older people .Low resistance to infection / immune system Workers most at risk . . such as drift eliminators should be replaced.Cooling towers should be inspected and thoroughly cleaned at least once a year. b) Corroded parts. c) Algae and accumulated scale should be removed. d) Cooling towers water should be treated constantly. .How to Prevent Legionnaires’ Disease? a) Good engineering practices in the operation and maintenance of the system. or other sources of organic matter .Locate away from fresh air intakes.Location of Cooling Towers . truck bays. .Locate away from kitchen exhaust fans. .Consider direction of prevailing wings. plants. .Consider future construction. Industry Code of Practice on Indoor Air Quality 2010 DOSH Malaysia* Ministry of Human Resources Table 1: List of Indoor Air Contaminants and the Maximum Limits . 15 – 0.0 – 26.50 .Acceptable Range for Specific Physical Parameters – Proposed 2010 Parameter (a) Air temperature (b) Relative humidity (c) Air movement Acceptable range 23.0 ºC 40 – 70% 0. List of Indoor Air Contaminants and acceptable limits Indoor Air Contaminants Chemical contaminants (a) Carbon dioxide (b) Carbon monoxide (c) Formaldehyde (d) Ozone (e) Respirable particulates (f) Total volatile organic compounds (TVOC) Biological contaminants (a) Total bacterial counts (b) Total fungal counts Eight-hours time-weighted average airborne concentration ppm mg/m³ cfu/m³ C1000 10 0.1 0.15 - - - - 500 1000 .05 3 0. airports. theaters. retail stores and shopping malls. auditoriums. – Office buildings. government facilities. entertainment areas are good candidates for DCV . conference or lecture halls.Carbon Dioxide and DCV • CO2-based DCV has the most energy savings potential in buildings where occupancy fluctuates. – Improved humidity control – In humid climates. DCV can prevent unnecessary influxes of humid outdoor air that makes occupants uncomfortable and encourages mould & mildew growth .Carbon Dioxide and DCV • Benefits – Improved IAQ – Increasing ventilation if CO2 levels rise to unacceptable levels. Typical Installation – AHU Room Return Air AHU Room CO2 sensor Supply Air AHU Fresh Air Fresh air damper Damper Actuator . Energy Monitoring Energy meter EFC3500 DA NF OS S Air Handling Unit Pt 500 RTD Flowmeter Pt 500 RTD . perpendicular to the lines of flux through a magnetic field of strength B.FARADAY’S LAW • Ui = When an electrical conductor of length L is moved at velocity v. the voltage Ui is induced at the ends of the conductor. • Ui = L x B x v – – – – Ui = Induced voltage L = Conductor length B = Magnetic field strength v = Velocity of conductor . The operation principle of inline magnetic flowmeters Full Bore Flange Type . temperature and pressure  Respond well to fast changing flows  Lower life-cycle costs When an electrical conductor moved at velocity.Type of Flow Meters • Electronic Flow Meters – Full Bore Flange Type Electromagnetic Qualities  Obstruction free  No moving parts  Wide flow range  Virtually no maintenance  Minimal installation requirements  Typical accuracy at 0.5%  Full BMS Integration  Measures the velocities across the pipe line cross section  Insensitivity to viscosity. the voltage is induced at the ends of the conductor . specific gravity. perpendicular to the lines of flux through a magnetic field of strength.25% and 0. With the transit time procedure.e. The velocity and direction of the sound rays change due to the transport of the sound waves in the fluid. the time is measured in which a sound wave takes to get around path 1.Type of Flow Meters Electronic Flow Meters Ultrasonic Measuring Principle Acoustic flow measuring procedures like the ultrasonic-flow measurement use sound waves above the hearing barrier.> 20 kHz for speed and flow measurement. point A. the sender Obstruction free No moving parts Wide flow range Virtually no maintenance Sensitive to pipe elbows and control valves Respond well to fast changing flows Full BMS Integration Low Cost of Ownership on larger pipe (>DN300) .e. i. I. What is a “Green Design” or Sustainable Design? • ASHRAE GreenGuide provides one definition for sustainable building design: “Sustainability is the providing of the needs of the present without detracting from the ability to fulfill the needs of the future” . What’s Green Building? • USEPA. renovation and even deconstruction. • .practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building’s lifecycle from design . maintenance.operation . construction.Sustainable or High-Performance building • Source: IEM Jurutera June 2010 Bulletin . Green Building Rating System Canada LEED Canada BREEAM Canada Green Globe UK BREEAM Italy Protocollo ITACA USA LEED Energy Star Green Globe Brazil GBTool Korea GBTool Japan China 绿色建筑评估标准 CASBEE Hong Kong India HK-BEAM LEED-India Malaysia Taiwan 綠建築標章 GBI Singapore Green Mark Australia Green Star . • Australia: Nabers / Green Star • Brazil: AQUA / LEED Brasil • Canada: LEED Canada / Green Globes • China: GBAS • Finland: PromisE • France: HQE • Germany: DGNB / CEPHEUS • Hong Kong: HKBEAM • India: GRIHA • Italy: Protocollo Itaca / Green Building Counsil Italia • Malaysia: GBI Malaysia • Mexico: LEED Mexico • Netherlands: BREEAM Netherlands • New Zealand: Green Star NZ • Philippines: BERDE / Philippine Green Building Council • Portugal: Lider A • Singapore: Green Mark • South Africa: Green Star SA • Spain: VERDE • Switzerland: Minergie • United States: LEED / Living Building Challenge / Green Globes / Build it Green / NAHB NGBS • United Kingdom: BREEAM • United Arab Emirates: Estidama GLOBAL GREEN TOOLS 1. 2. 3. 4. 5. 6. 7. 8. 9. BREEAM, UK – Building Research Establishment Environmental Assessment Method (1990) LEED, USA – Leadership in Energy and Environmental Design (1996) BEAM, Hong Kong – Building Environment Assessment Method (2003) EEWH, Taiwan – Green Building Evaluation System (2003) Green Star, Australia/New Zealand (2003) CASBEE, Japan – Comprehensive Assessment System for Building Environmental Efficiency (2004) Green Mark, Singapore (2005) Green Building Index, Malaysia (2009) Greenship, Indonesia (2010) GBI : An Integrated Design Approach FM Service Provider Owner /User Architect Civil Engineer Commisiong Specialist Energy Consultant Working together to achieve Goals Mechanical Engineer Electrical Engineer GBIF Contractor Vendors Sub-cons Quantity Surveyor Landscape Architect . cp” denotes excluding car park .Building Energy Intensity BEI = (TBEC .GLA*FVR) where: “ex.DCA .CPEC .DCEC)*(52/WOH) (GFAex.cp . mechanical ventilation.CPEC . sump pumps and plug loads (car washing facilities).DCEC)*(52/WOH) (GFAexcl carpark . Installations serving the whole building (such as hydraulic pumps and fire pumps) shall not be included. DCEC: Data Centre Energy Consumption (kWh/year) for operation of the Data Centre equipment and for controlling its indoor environment (air-conditioning. lifts.GLA*FVR) Where. GFAexcluding carpark : Gross Floor Area of buildings exclusive of car park area (m2) .BEI = (TBEC . mechanical ventilation fans. CPEC: Carpark Energy Consumption (kWh/year) for carpark area (which is not air-conditioned) and typically covers artificial lighting. TBEC: Total Building Energy Consumption (kWh/year) for all landlord and tenancy areas.DCA . lighting and plug loads). The sum of GLA. retail and other functional spaces of GLA. cafeteria. 52: Typical weekly operating hours of office buildings in KL/Malaysia (hrs/wk) = 2.DCEC)*(52/WOH) (GFAexcl carpark . retail.CPEC .BEI = (TBEC . common areas and service areas should equal the GFA excluding car park.DCA . The FVR (%) of GLA is equal to the non-occupied lettable area divided by the GLA.700 hrs/annum WOH: Weighted Weekly Operating Hours of GLA exclusive of DCA (hrs/wk) . gymnasium and club house inside the building but excluding all common areas and service areas.GLA*FVR) DCA: Gross area of Data Centre (m2) GLA: Gross Lettable Area (m2) refers to the total functional use area for commercial purposes such as office. restaurant. FVR: Floor Vacancy Rate is the weighted floor vacancy rate of office. BEI EE5 pts Office Retail Hotel 2 150 240 200 3 140 225 190 5 130 210 175 8 120 195 160 10 110 180 150 12 100 160 135 15 90 145 120 Hospital 200 190 175 160 150 135 120 Etc ? ? ? ? ? ? ? . – Landlord and/or tenant – Lift and escalator – Major water pumping system – Central air-conditioning system – Car park and common area lighting/power system – External and façade lighting Separate electricity metering to be linked to EMS .Electrical Sub-Metering • Separate metering provided for the following. . THANK YOU Ir. GBIF.my Tel: +6012 – 201 9319 .. MASHRAE Email: [email protected]. NG YONG KONG. P.Eng.