FAIRCONDITIONINGARCHITECTURETRAINING OF TRAINERWORKSHOP
Direct/Indirect Evaporative CoolingDX.X
Table of Contents1. Why, What, How, Where …......all about cooling
2. Various cooling technologies
1. The Good, Bad & Ugly about the technologies
3. Potential of alternate cooling technologies
4. Opportunities, benefits and constrains
5. Role of architects, engineers and consultants
6. Questions
Why and What about cooling• Two types of cooling as the industry knows
1. Process cooling2. Comfort cooling
• Comfort cooling in buildings• Human body radiates heat due to metabolism• Ambient working conditions demand lower of temperature in working spaces• As per NASA study, human resources best efficiency in comfort zones• Definition of comfort zone varies on various factors
Ventilation or cooling• Very important question need to answered by all stake holders• Taking away heat generated by the body is basic requirement• Movement of air over skin to address ‘feel’ factor • Continues supply of Oxygen in turn fresh air• Take away pollution from the space
Why need to pay attention to end use energy efficiency?1. Fossil fuel is finite
2. Alternative energy is expensive
3. Predicted high future demand
4. Demand outstripping the supply already
5. India has the second highest population
6. GHG and Co2 emissions.
Breakup of electricity consumed in commercial sector
Historic means & ways for comfort cooling• India has long history of space cooling • Taj maha, Hawa Mahal. GolGhumbaj are some of the distinct
examples • Khus curtains were part of mid and large sizes houses till
recent past • ‘ Matka- earthen pot’ is still best cooling device pan India• Appropriate cross ventilating openings, thick stone wall and
large water bodies was part of our building science.
The new methods for cooling
Air Coolers / Evaporative cooling
Air Conditioners
Air Cooler - Evaporative Air Cooling
Psychrometry and Psychrometric chart• Psychrometry is the science of studying the thermodynamic properties of
moist air• These properties are used to analyze conditions and processes involving
moist air. • Moist air is a mixture of dry air and water vapor. In atmospheric air, water
vapor content varies from 0 to 3% by mass.• Psychometric chart graphically displays several physical properties of air
over a broad range of conditions. Knowing the relationship of these air properties aids the task of air conditioning system design and analysis.
Psychrometric chart
Psychrometric processes
Psychometric process
Mathematical process
DBS = DBA ( DBA –WBA ) x Efficiency
DB – Dry Bulb temp
WB- Wet Bulb temp
Application• Large working spaces like
• Factory Sheds, • Ware hoses • Process pants with high heat areas• Commercial kitchens• engine testing, repairing etc
Benefits• Environmentally friendly• Low power consumption • Use of Natural refrigerant for cooling• Sustainable, GREEN and Energy Efficient
Few Short comings• 100% fresh air or Once through• Moist laden supply air• Limited by ambient conditions hence geography as well as
time of year• Needs equal amount of exhaust – challenge in office buildings• Slightly higher air velocities as well as quantities
Other option – Air Conditioners
How it works
Advantages• Control on Temp & Humidity at push of button• Omni presence across domestic, commercial and industrial domain• Out of the box solutions for all most all comfort cooling applications• Sizing suitable for various applications • Proven and know technology for more than 100 years
Air Conditioners- Advantage and applications
Short comings• Most energy guzzling utility across commercial buildings• Deploys Ozone depleting chemicals• Non sustainable• Higher on carbon emission• The re circulating working hampers IAQ• Efficiency hampers in high ambient conditions• No air ‘ conditioning’ as per definition it is only cooling &
dehumidification
Indirect Direct Evaporative CoolingThird Alternative
Indirect Evaporative Cooling
Sensible Cooling Heat exchanger
Heat Exchanger
IDEC Schematic
Psychometric process
Mathematical process- IDEC
• DBFS = DBA ( DBA –WBA ) x Efficiency
• DBS = DBFS ( DBFS –WFS ) x Efficiency
Applications• Factory shed
• Ventilation applications
• Warehouse
• Laboratories
• Air compressor room
• Panel room
• Solvent store room
• Pre-cooling
• Office complex
• Club house
• Entrance lobby
• Cafeteria
• Malls
• Lecture / training room
• Function hall
• Kitchen/Laundry
Case : Options for Factory Shed Cooling
Comparative analysisParameter Units Arka 2 Stage Cooling Evap cooling systems
Location CITY Pune Pune
Summer Dry bulb ⁰C 38 38
Summer Dry bulb ⁰C 20.5 20.5
supply air Temperature ⁰C 18 23
Space temperature ⁰C 26 26
Selected air quantity CFM 19290 45000
Sensible Heat removed TR 25 21.87
Absorbed Power IKW 9.6 28
Connected load KW 11 30
Water use LPH 131 306
Economics
Operating Time HOUR/YEAR 2000 2000
Power Terrif INR/KWH 10 10
Installed cost INR Lacs 9 8.1
Operating cost INR Lacs 1.3 5.6
What future cooling looks like• Combining best of both the worlds• Divide & rule• Sensible Cooling by evaporative cooling while dehumidification by
refrigeration• Fresh air integration improves IAQ• Best EER and optimum energy consumption• Wider geographic acceptability
Future – Two Stage IDEC+ Refrigeration
• Low cost comfort cooling solution• 30% Fresh air with pre cooled
return air• Suitable for retrofits & new
installations• Uses lowest amount of chilled water
for dehumidification• Semi automatic controls for
seasonal operation• Suitable for all climate zones
Two Stage / Hybrid Concept
Summary• IDEC- Third alternative for comfort as well as process cooling
application• Two Stages of cooling• Water as refrigerant • Low supply tamp, Low RH , Low power & water consumption• Suitable for large industrial and commercial places• Low OPEX , cost effective alternative
Role of professionals• Adopting technologies and solutions suitable to Indian climatic conditions.• People, Process & Product approach• Air distribution need equal importance in deign• Natural refrigerants is only way forward• Need well sync between all stake holders during projects.• Decision should be on basis of E1 and not L1• Architects can design while engineers can deliver the change.
Any questions ?