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 ?