Buildings contribute over 40 % of the total global primary energy use corresponding to 24 % of the CO2 emissions of the world (IEA 2008). Building heating, ventilation, and air-conditioning (HVAC) systems are responsible for about half of the energy use in buildings.

1. Heat Management Techniques In Green
Buildings : A Review
By- Amardeep Singh (00720703417)
Rithik Sharma (03320703417)
Prashant Tiwari (02520703417)
Prajjwal Gautum(02420703417)
ETEN 419

2. Topics Covered
• Introduction
• What are Heat Management Systems?
• The need for adoption of more efficient and greener Heat Management systems : India
• Types of Heat Management Systems
• 1. Active and Passive systems
• Comparison of Active and Passive Systems
• Hybrid Systems
• 1. Hybrid Systems: Tested
• A Critical Review of EAHE: In Chandigarh
• Heat Management in CII Sohrabji Godrej Building
• Heat Management Systems in Indira Paryavaran Bhawan
• Advantages of heat management systems in green buildings: A summary
• Conclusion
Chandigarh
CII Sohrabji Godrej Building
Indira Paryavaran Bhawan

3. Introduction
• Green Building: In its design, construction or operation, reduces or eliminates negative
impacts, and create positive impacts, on climate and natural environment.
• Preserves precious natural resources like energy which broadly constitutes:
• Electrical Energy
• Thermal Energy
• Buildings contribute over 40 % of the total global primary energy use corresponding to 24
% of the CO2 emissions of the world (IEA 2008). Building heating, ventilation, and air-
conditioning (HVAC) systems are responsible for about half of the energy use in
buildings. [1]
• Current demand is increased energy efficiency, i.e., indoor thermal comfort with minimal
energy consumption in buildings by use of certain techniques.
• In this presentation we shall study some of these Heat Management Techniques being
used in Green Buildings and their real world implementations.
[1] Sobti, J., Singh, S.K. Earth-air heat exchanger as a green retrofit for Chandīgarh—a critical review. Geotherm Energy 3, 14
(2015)

4. What are heat management systems?
• Objective: To provide thermal comfort and
acceptable indoor air quality.
• Achieved by performing Heating, ventilation,
and air conditioning.
• Not limited to active energy consuming
machines: ACs and Ventilation fans/Turbines
• Include passive techniques: Trombe walls
,PCMs[a].
• Use of active and passive heat management
systems or HVACs can lead to significant
decrease in the annual energy consumption of a
building.
[a] PCMs or phase changing materials change their phase according to variation in temperature and store heat in the process
A roof HVAC unit
A roof Ventilation
turbine
A Tromble wall (e.g.
of a passive heat
management
system)
A solar chimney

5. The need for adoption of more efficient and greener
Heat Management systems : India
[2] Davis, L. W., & Gertler, P. J. (2015). Contribution of air conditioning adoption to future energy use under global warming. Proceedings of the National Academy of Sciences, 112(19),
5962–5967
[b] "Cooling degree days", or "CDD", are a measure of how much (in degrees), and for how long (in days), outside air temperature was higher than a specific base temperature. They are
used for calculations relating to the energy consumption required to cool buildings.
• India is warm country which houses a
growing population of 1.38 billion and is on
the list of countries with the largest air
conditioning potential in the world.[2]
• Traditional systems damage the ozone layer
by CFCs.
Comparison of air conditioning
potential of Countries in terms of
CDDs[b]

6. Types of Heat Management
Systems
Passive and Active Systems

7. Passive Heat Management Systems
• Uses ambient energy or renewable energy sources instead of purchased energy. e.g solar energy.
• No mechanical equipment's and energy is required.[c]
On the basis of utilization of incoming solar radiation, Passive systems can be broadly categorized into two
systems -
e.g., Natural Ventilation Techniques (based on the temperature
differences of air).
e.g. 1. Trombe wall
2. Solar Chimney
3. PMCs[d]
4. Thermal Insulation Solutions
We will discuss some of these techniques in the coming slides.
[c] In the operation stage
[d] PCMs or phase changing materials change their phase according to variation in temperature and store heat in the process
Direct Gain
Systems
Indirect Gain
Systems

8. 1. Trombe Wall
• South facing thin glazed walls.
• Take solar heat and regulate air circulation
• Can be used throughout the year
• In day hours vents are open to ventilate the
air and during night time vents are closed to
maintain the room temperature.
• Among the passive solar heating strategies,
Trombe walls can harmonize the relationship
between humans and the natural
environment.
• Simple configuration, high efficiency, zero
running cost
• Energy heating savings of upto 16.36% [5]
[5] Briga-Sá, A., Martins, A., Boaventura-Cunha, J., Lanzinha, J. C., & Paiva, A. (2014). Energy performance of Trombe walls: Adaptation of ISO 13790:2008(E) to the Portuguese reality.
Energy and Buildings, 74, 111–119
[e] The red arrows depict warm air while the blue arrows depict cool air.
Trombe wall collects heat in
the day
Heat is released during the
night
Air flow in Trombe Wall [e]
A school with Trombe wall
in Salta, Argentina

9. 2. Solar Chimneys
• They work under principle of stack effect[f], as
shown in fig
• In day time it absorbs solar energy but during
night time requires heat storage mass.
• During the day solar energy heats the chimney
and the air within it, creating an updraft of air
in the chimney.
• The Suction created at the chimney's base can be
used to ventilate and cool the building below.
• It can be engaged in various applications i.e.
ventilation, power generation, etc.
[f] Stack effect or chimney effect is the movement of air into and out of buildings due to a difference in indoor-to-outdoor air
density resulting from temperature and moisture differences
Air flow in accordance to stack effect A solar chimney in
Tanga school, Frankenberg, Sweden
A power plant using a Solar Chimney for electricity production using
Stack Effect

10. 3.PCMs (Phase Change Materials )
• They are substances which absorb or release
large amount of so called latent heat[g] when
they go through a change in their physical
state, i.e., from solid to liquid and vise-versa.
• In its infancy when it comes to use of building
materials with impregnated PCMs[6]
• Latent heat of materials is the key factor for
increasing/decreasing the duration of storing
heat.
• E.g. Paraffin's, Fatty Acids, Salt Hydrates,
Metallic etc.
[g] Latent heat can be understood as energy in hidden form which is supplied or extracted to change the state of a substance without changing its temperature
[6] Zhou, D., Zhao, C. Y., & Tian, Y. (2012). Review on thermal energy storage with phase change materials (PCMs) in building applications. Applied Energy, 92, 593–605.
Gypsum wall board with Micronal PCM[6]
thermalCORE phase-change drywall[6]

11. 4. Thermal Insulation Systems
• Application of thermal insulations in space
heating/cooling is increasing exponentially.
• Develops an artificial envelope around the
building.
• Prevents heat/cold ingress from
surroundings.
• At least 10 degree Celsius temperature
difference in comparison to without
applying thermal insulation.[7]
• Keeps required temperature for longer
periods and facilitates human comfort.
[7] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-08
[8] Owens Corning India pvt ltd
Thermal insulation installation on a wall
Impact of roof and wall insulation with 50 mm insulation [8]

12. Active Heat Management Systems
• Uses purchased energy to keep building temperature and ventilation levels comfortable.
• They have become quite popular as they are energy efficient and environment friendly.
• GCHE systems have multiple primary objectives. These are to achieve the best operational
efficiencies, the lowest possible operational cost and run environmentally safe, to have lowest
possible initial cost and surface area, to increase interior comfort level. [8]
We will study the following GCHEs in the following slides-
1. EAHE( Earth Air Heat Exchange) Systems
2. GSHP(Ground Source Heat Pump) Systems
[9] Soni, S. K., Pandey, M., & Bartaria, V. N. (2015). Ground coupled heat exchangers: A review and applications. Renewable
and Sustainable Energy Reviews, 47, 83–92.
On of the more popular technologies used are GCHEs (Ground Coupled Heat exchangers)

13. Earth Air Heat Exchanger Systems
• Consumes electricity to blow the air and use
earth as heat sink for heating/cooling.
• Earth temperature remains constant throughout
the year to the annual average temperature
approximately 5 meter deep. [6]
• Constant temperature characteristic of earth is
utilized for heating/cooling
• Preferred in areas with fluctuating ground
temperature.
[6] Soni, S. K., Pandey, M., & Bartaria, V. N. (2015). Ground coupled heat exchangers: A review and applications. Renewable
and Sustainable Energy Reviews, 47, 83–92.
Earth air heat exchanger system[9]
EAHE pipes being laid down[10]

14. Ground Source Heat Pump Systems
• Follows principle similar to a refrigerator.
• Uses electrical power to circulate the fluid
through the loop for utilizing earth’s constant
temperature to exchange heat.
• It is suitable for all seasons. [7]
• Trench depth ~.5 to 1.5 meters
[7] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging
Technologies, 10(1): 01-08
GSHP plumbing being laid out
A GSHP illustration

15. Chilled Beam Method
• Chilled beams deliver cooling to rooms
primarily by using cool water in coils
that exchange heat with room air, so
reducing the air temperature.
• The principal advantage of using a
chilled beam – as opposed to an ‘all air’
air system – is that moving heat
around a building can be undertaken
far more efficiently by pumping cool
water in pipes than by moving the
same amount of heat in ducted air. [11]
[11] ICIBC Journal, Module 65: Applying chilled beams to reduce building total carbon footprint
Cross section view of an Active Chilled Beam
Cross section view of an Active Chilled Beam

16. Advantages of using chilled beams in place of
VAVs[l]
• Consumes 20-30% less
energy
• Silent Operation leading to
maximized comfort
• The size of ducting provided
is lower than traditional
VAVs leading to more
efficient building design.
• Much Lower maintenance
• Lower Installation Costs
[l] Variable air volume is a type of heating, ventilating, and/or air-conditioning system. Unlike constant air volume systems,
which supply a constant airflow at a variable temperature, VAV systems vary the airflow at a constant temperature.
A chilled beam installation in
Fenger,UK
An Office space with chilled
beams installed

17. Comparison of Active and Passive techniques
Parameters Passive Techniques Active Techniques
Cost Low High
Fuel Renewable Fossil or renewable or both
Applicability Restricted In all climatic conditions and time
of day
Efficiency Low High
Payback period Moderate Low
CO2 Almost Zero Moderate
[7] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging
Technologies, 10(1): 01-08
[7]

18. Hybrid Heat Management Systems
• Active and passive systems when used in conjunction tend to give superior efficiency and
usability.
[7] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging
Technologies, 10(1): 01-08
Hybrid system working concept[7]

19. Hybrid Systems: Tested
• An experimental setup of EAHE system plus
conventional air conditioner (AC) was built at
Ajmer, India.
• Test had four modes of operation, they were as
follows,
[10] Misra, R., Bansal, V., Agarwal, G. D., Mathur, J., & Aseri, T. (2012). Thermal performance investigation of hybrid earth air
tunnel heat exchanger. Energy and Buildings, 49, 531–535.
Mode 1
(Base)
100% air conditioned to the room by AC
Mode 2 AC and EAHE both provide full conditioned air
Mode 3 EAHE cools AC coils >AC cools room
Mode 4 EAHE provides 50% to AC coils and 50% directly
to the room
Experimental set-up of hybrid EATHE system
[10]
Results
Modes Power Consumption as compared to
Mode-1
2 6% less
3 18.1% less
4 16% higher

20. A Critical Review of EAHE
in Chandigarh

21. [11] Goswami and Dhaliwal 1985; Mihalakakou 1997; Paepe and Janssens 2002; Ozgener et al. 2013
[12] Kusuda 1975; Bhardwaj and Bansal 1981; Jacovides et al. 1996; Bisoniya et al. 2013; Bisoniya et al. 2014
• The nearly constant ground temperature at a certain depth has been regarded as a passive means for the
heating and cooling of buildings by several researchers. [11]
• About 1.5 to 2 m remains constant throughout the year and is equal to the annual average temperature of
a particular place. [12]
• The earth-air heat exchangers (EAHE) is basically a series of pipes buried underground at a
particular depth through which fresh atmospheric air flows and gets cooled in summer and
warmed in winter.
Working of EAHE system

22. The amount of heat exchanged between the air and the surrounding soil depends upon various
parameters as follows:
Surface area and
length of the pipes
Water content of
inlet air
Dampness and
temperature of
the earth
Air velocity, Soil
type, material and
surface conditions
of the pipes
Depth of the pipes
from ground
surface
[13] Kumar et al. 2006
EAHE: Earth Air Heat Exchanger
Factors Affecting EAHE Performance.
[13]

23. EAHE System are be judged by energy analysis
[h] EPBT: Energy Pay Back Time
[I] SEER: Seasonal Energy Efficiency Ratio
EPBT
•Number of years required to recover energy invested, i.e., in
manufacturing, transportation, installation, operation, and
maintenance of the system while in use, is called EPBT.
•Ratio of embodied energy of the EAHE system (kWh) to total yearly
energy output of the EAHE system (kWh)
SEER
•The seasonal energy efficiency ratio (SEER) is the measure of the
heating/cooling efficiency of heat pump/air conditioners.
•Total monthly heat-energy gain/loss (in winter/summer, respectively)
from the room air to the total monthly energy consumed by the EAHE.
•It should be more than ‘1’ for EAHE to be viable.
[h]
[I]

24. Climatic Conditions of Chandigarh
[14] Official website of the Chandīgarh Administration (2015)
• Location
• Latitude 30.74N; Longitude 76.79E
• Altitude 321m.
• Located in the foothills of the Shivalik hill range in the north.
• Humid sub-tropical climate characterized by very hot summers,
mild winters, unreliable rainfall, and a great variation in
temperature.
• Winter Minimum 1–16 °C
• Summer Maximum 27–44 °C
• The Average Rainfall Is 1110.7 Mm. [14]
Chandigarh drone view

25. Requirement of Cooling in Chandigarh
• Chandigarh requires cooling from April
to October and minimal heating in the
months from October to April. [14]
[14] Official website of the Chandīgarh Administration (2015)
Average monthly temperature chart of Chandigarh. [14]

26. [15] chdengineering.gov.in Public Database
Demand Of
Electricity In
Chandigarh During
Peak Season Is
350 MW
Gap can be easily
bridged Using EAHE
Availability 324MW
Fulfilling the Demand of Energy
• There is a gap between the demand and the availability of energy in Chandigarh
which can be easily fulfilled by the implementation of EAHE in buildings. [15]
Flow chart depicting Gap bridging ability of EAHE
Energy Deficit = 26MW

27. A Pilot Test
• A pilot test was carried out for -
• A 50 m long
• 10-cm diameter mild steel pipe with wall
thickness of 3 mm
• placed at a depth of 3 m
• The air was moved at 11 m/s through the
pipe. [16]
[16] Mihalakakou et al. 1995; Mihalakakou 1997
• It was observed that EAHE caused a drop of 14 °C in the summer
months and an appreciable rise in the winter months in the circulated
air.
Pictorial representation of EAHE system

28. • Performance can be
enhanced by integrating an
evaporative cooler at the
outlet and a solar air-heating
duct at the exit end during
the summer and winter
season, respectively. [17]
[17] Bansal et al. (2009, 2010) carried out a performance analysis of earth-air heat exchangers (EAHE) systems for winter heating
and summer cooling in the city of Ajmer (India).
4500MJ
Alone
3109MJ
Integrating
with
evaporative
cooler
7609MJ
Enhancement of EAHE performance
Results show that an EAHE
system alone provides
4500 MJ of cooling effect
during summers, whereas
3109 MJ of additional
cooling effect can be
achieved by integrating an
evaporative cooler with the
EAHE.
Pictoral Representation of the result

29. Heat Management in CII
Sohrabji Godrej Building
in Telangana,India

30. Features of CII Sohrabji Godrej Building (1/3)
• A central courtyard and colonnaded corridors
ensure that the hot air cools before entering the
interiors.
[18] Nirman ,CII Sohrabji Godrej Green Building – A guiding Light.
• Two air-cooling towers are erected where air
is cooled up to 8 degrees by sprinkling
water. [18]
Image showing Courtyard of CII
Sohrabji Godrej, Telangana
Diagram showing Air Tower of CII Sohrabji Godrej, Telangana

31. • 55% of the roof is covered with
terrace garden, helping reduce the
interior temperatures.
[19] Indian Green Building Council Public Database
• Low heat transmitting double
glazing for reduced heat
intake.
Depicting ‘Green Roof’ and ‘Glazing’ (2/3)
Also, The building has certified as LEED ‘Platinum’ certification’
Image showing Terrace Garden of CII Sohrabji Godrej,
Telangana [19]
Image showing Glazing of CII Sohrabji Godrej, Telangana [19]

32. [j] Autoclaved Aerated Concrete (AAC) blocks are produced using materials including silica sand, lime, cement, gypsum, water, fly-ash and aluminium powder.
[k] U-value, (thermal transmittance) is the heat transmission in unit time through unit area of a material or construction and the boundary air films, induced by unit temperature difference between
the environments 2 on each side. U-value is expressed in W/m K.
Additional features of the building (3/3)
• Autoclaved Aerated Concrete (AAC) [j] blocks
for facades reduces 15-20% load on air-
conditioning.
• Over-deck insulation, a type of roof insulation.
• Extruded polystyrene glasses which provide
optimum lightning and minimum U-value [k]
• Vertical gardens to ensure less heat in walls.
Diagram representing the over-deck insulation
Pores in AAC aiding
in Insulating
properties

33. Heat Management Systems in
Indira Paryavaran Bhwan
in Delhi,India

34. [20] NZEB case studies : Indira Paryavaran Bhawan
Ministry of Environment and Forest (MoEF)
Features of the building(1/4)
• It has ‘5 Star’ GRIHA rating and also a LEED
‘Platinum’ rating.
• Orientation: Building is north south oriented, with
separate blocks connected through corridors and
a huge central court yard. Orientation minimizes
heat ingress and increases aesthetic appeal.
• Ventilation: Central courtyard helps in air
movement as natural ventilation happens
due to stack effect.
• Windows and jaalis add to cross ventilation.
• Windows with low heat transmittance index
glass. [20]
Image showing North facing of Indira Paryavaran
Bhawan, Delhi

35. [20] NZEB case studies : Indira Paryavaran Bhawan
Ministry of Environment and Forest (MoEF)
• Use of high reflectance terrace tiles to prevent heat ingress.
• 160 TR of air conditioning load of the building is met through Chilled
beam system. Chilled beam are used from second to sixth floor. This
reduces energy use by 50 % compared to a conventional system. [20]
Image showing Chilled Beam Installation during construction of Indira Paryavaran
Bhawan, Delhi
Features of the building(2/4)

36. [20] NZEB case studies : Indira Paryavaran Bhawan
Ministry of Environment and Forest (MoEF)
[k] TR or Tons of Refrigeration- It is defined as the rate of heat transfer that results in the freezing of 1 short ton of pure ice at 0 °C in 24 hours.
• There are 180 vertical bores to the depth of 80 meter all along the
building premises. Minimum 3 meter distance is maintained between
any two bores.
• Each bore has HDPE pipe U-loop (32mm outer diameter) and grouted
with Bentonite Slurry. Each U-Loop is connected to the condenser
water pipe system in the central air conditioning plant room.
• One U-Loop has 0.9 TR
[k]
heat rejection capacity. Combined together,
160 TR of heat rejection is obtained without using a cooling tower.
[20]
Geothermal heat exchange system used (3/4)

37. [20] NZEB case studies : Indira Paryavaran Bhawan
Ministry of Environment and Forest (MoEF)
Pictoral Depiction of the Geothermal Heat Exchange
System used (4/4)
Image showing heat exchange system at Indira Paryavaran Bhawan,
Delhi [20]

38. Advantages of heat management
systems in green buildings: A
Summary

39. Advantages of Earth-Air heat exchanging system [1/2]
[21] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-08.
[m] The coefficient of performance or COP of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work required. Higher COPs equate to
Advantages of
EAHE
Minimized air
pollution
Use of PCM
enhanced the
cooling
effectiveness of
EAHE system
as compared to
conventional
system by 47%.
Higher
COP[m]
Simpler
design
Low
maintenanc
e, and
operational
costs.
[21]

40. Disadvantages of Earth-Air heat exchanging system(2/2)
[21] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-08.
Disadvantages
of EAHE
No uniform
Temperature
is Achieved
Condensation
Occurs in the
Pipe
Growth of
micro-
organisms
High
Installation
Cost
Decrease in
quality of
air
[21]

41. Advantages of Hybrid Systems in Green Buildings
[21] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-08.
Eco-
Friendly
Higher
Efficiency
And
usability
Economically
Feasible
Suitable for
Sustainable
Developmen
t
Solar assisted h
eat pump could
reduce 8-15%
power Consump
tion.
Conserve
10-30% of
total
consumptio
n
[21]

42. Advantages of Thermal insulation in green buildings.
• Thermal insulations prevents heat/cold ingress from
surroundings. It keeps at least 10C temperature difference
in comparison to without applying thermal insulation.
• Low to Zero maintenance
• Decreases the load on traditional HVAC systems with
minimal cost and complications.
[21] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-
08.
[21]

43. Hybrid systems vs Unity systems
Parameters Unity systems Hybrid systems Remarks
Cost Low High
It can be reduced if
implemented during
building
planning/construction
stage.
Life Moderate Moderate
Life can be increased
by proper
maintenance.
Efficiency Low High
It depends on
appropriate
conditions.
Energy savings Low High
Saves the fossil fuels
and environment.
Payback period High Low
Hybrid systems are
economically feasible
[21] Soni, SK (2019). Heating/Cooling Techniques used in Green Buildings: A Review. International Journal on Emerging Technologies, 10(1): 01-08.
[21]

44. Conclusion
• As our study shows the imminent Air
Conditioning/Heating need of the country
are growing exponentially, The Green
Heat Management Techniques have
proven themselves to be a real game
changers.
• YoY growth of energy needs, need to be
combated with renewable energy
installations and innovative technologies
such as the ones studied in this
presentation.

45. • Thankyou