AIR CONDITIONER DESIGN - MECHANICAL ENGINEERING

ACMV DESIGN

1. SHIN NIPPON LANKA (PRIVATE) LIMITED NO. 309/1, COLOMBO ROAD, WELISARA. AIR CONDITIONG SYSTEM DESIGN CONDUCTED BY: W A D N INDIKA

2. What is Air Conditioning ? Air conditioning  (often referred to as  A/C ,  AC  or  aircon ) is the process of altering the properties of air (primarily temperature and humidity) to more comfortable conditions, typically with the aim of distributing the conditioned air to an occupied space to improve thermal comfort and indoor air quality.

3. Psychrometrics The psychometrics deals with the thermodynamic properties of moist air and uses these properties to analyze conditions and processes involving moist air. Dry Bulb Temperature (DB) Relative Humidity ( Rh , φ ) Wet Bulb Temperature (WB) Dew Point Temperature (Td) Volume Cubic Meter Per Kilogram Dry Air (v) Enthalpy (h)

4. Psychrometric Chart Pychrometric Chart More Detail Cooling Coil Sizing Saturation Pressure of Water Vapour ( Pws ) is only a function of a given temperature (t) it depends on atmospheric pressure Psychrometer is used to measure Dry Bulb (DB) & Wet Bulb Temperature (WB) . Relative Humidity (RH) can be estimated referring a Relative Humidity Table

5. Thermal Comfort Thermal Comfort Depend on Following Factors Space Temperature Relative Humidity Air Movement ( Velocity) Type of Cloth Type of Actitivity Comfort Zone

6. Indoor Air Quality Indoor Air Quality (IAQ) is a term which refers to the air quality within and around buildings and  structures, especially as it relates to the health and comfort of building Common Pollutant Second-hand smoke Molds and Other Allergens Carbon dioxide ,Carbon monoxide Others Gases Air Changes (Fresh air & Exhaust ) Volatile Organic Compounds (VOC) Legionella and Other Bacteria Dust & Other Particulate Matters Table1 Table2 Filter

7. Cooling Load RTS Cooling Load Principal can be used to calculate cooling load of a building in a given time Window Wall/Roof/Partition Wall Lighting Occupants Equipments Infiltration Airside equipment fan power RTS overview Heat Load Cal

8. Type of Air Distribution Devices Grille Diffuser Air Valve Flow Regulators & Dampers Fire Dampers Light Troffer VAV Boxes Catalogue VAV Catalogue Duct Layout

9. Duct Sizing Duct sizing is done considering air velocity , application and geometry of the section. Ductulator Excel Spread Sheet Velocity Duct Calculation Duct Size Chart

10. Airside Equipment AHU FCU (Ceiling Concealed / Wall Mounted) Ceiling Cassette AHU Fan Configuration FCU Catalogue FCU Selection Data Ceiling Cassette Unit AHU Configuration

11. Refrigeration Cycle Type of refrigerant & Data table Single stage, two stage ,three stage vapour compression cycle Cascade System Ideal Cycle Efficiency ( COP, EER, kW/RT) Actual System Efficiency AHRI Condition (table) Ref. Cycle Ref. Type Ref. Date R134a Ref. Date R123 COP conv

12. Refrigeration Equipment Window Units Split Units Multi-Split System Heat Pumps VRV System Package Unit Chillers Catalogue 1 Package Unit Chiller

13. Cooling Tower Cooling Tower Type Selection Parameters Location Noise Material of Construction Natural Frequency & VSD operation Selection Chart Cross Flow CT CT Layout

14. Pump NPSH What does NPSH stand for NPSHa = (P1 - Pv) x 10.20 + Z1 - Hf Sp.Gr. where: NPASHa = Net Positive Suction Head (available) P1 = Absolute Pressure (Bar) Pv = Vapor Pressure at Pump temperature (Bar) Z1 = Height of liquid surface above pump suction (m) Hf = Friction loss in suction pipe (m) P1 = 1.013 Bar Pv = 0.048 bar @ 32 deg.C. Z1 = -3 m Hf = 2.4 m Sp.Gr. = 0.997 NPSHa 4.472618 m NPSHr 2 m At least NPSHa is equal or greater than NPSHa x 150% NPSHa > NPSHr OK Pump Curve NPSH Graphic

15. Chilled Water & Condenser Water Pipe Sizing Generally water pressure drop upt0 400 Pa/m is recommended for pipe above 50m diameter. Water flow velocity upto 1.2 m/s is main criteria for smaller size pipe. How to estimate chilled / condenser water flow Rate Pipe size calculation AHRI 550 Chiller plant Pipe Chart AHRI 551

16. Energy Efficient Chiller Plant Water cooled chiller (0.5 ~ 0.55 kW/RT) Chilled Water Pump ( 0.05 kW/RT) Condenser Water Pumps ( 0.05 kW/RT) Cooling Tower ( 0.03 kW/RT) Pipe system with less restriction to water flow Low Evaporator flow Chiller Plant Plant Concept

17. AHRI CERTICICATION Chiller Chiller Data

18. Water Cooled & Air Cooled System Comparison Energy Savings & Operation Cost CO2 Emission Investment Space Daily operating time Weather condition CTI Comparison

19. General Discussion Chiller submittal copy Air lock , Air vent & Chilled water system pressure Chiller gas charging procedure Condensation on Glass partition Pipe freezing & Hot tapping Water charging procedure Pump testing procedure AHU Testing procedure Cooling tower thermal performance testing at site Coandă effect Pressure breaking Data

20. Q & A

21. SHIN NIPPON LANKA (PRIVATE) LIMITED NO. 309/1, COLOMBO ROAD, WELISARA. Thank you