Heating Systems,Ventilation,Refrigeration & Air-conditioning in buildings

1. 10/13/2019
ENERGY EFFICIENT
EQUIPMENTS
• SHAVI JAMWAL
• SHAILJA KUMARI
• VIBHA KACHROO

2. What is energy efficiency?
• Energy efficiency is "using less energy to provide the same service“
• Efficient energy use, sometimes simply called energy efficiency, is
the goal to reduce the amount of energy required to provide products and
services. For example, insulating a home allows a building to use less
heating and cooling energy to achieve and maintain a comfortable
temperature.
• Improvements in energy efficiency are generally achieved by adopting a
more efficient technology or production processes or by application of
commonly accepted methods to reduce energy losses.
• There are many motivations to improve energy efficiency. Reducing
energy use reduces energy costs and may result in a financial cost saving
to consumers if the energy savings offset any additional costs of
implementing an energy efficient technology. Reducing energy use is also
seen as a solution to the problem of reducing carbon dioxide emissions.
• Energy efficiency and renewable energy are said to be the twin
pillars of sustainable energy policy and are high priorities in the
sustainable energy hierarchy.

3. • Energy efficient buildings (new constructions or
renovated existing buildings) can be defined as
buildings that are designed to provide a significant
reduction of the energy need for heating and cooling,
independently of the energy and of the equipments
that will be chosen to heat or cool the building
• This can be achieved through the following elements:
bioclimatic architecture: shape and orientation of
the building, solar protections, passive solar systems
high performing building envelope: thorough
insulation, high performing glazing and windows,
air-sealed construction, avoidance of thermal bridges
high performance controlled ventilation: mechanical
insulation, heat recovery

4. Only when the building has been designed to minimise the energy loss, it
makes sense to start looking at the energy source (including renewable
energy) and at the heating and cooling equipments. We designate this
approach as the Trias Energetica concept.
The trias Energetica Concept

5. HEATING SYSTEMS

6. 10/13/2019ENERGY EFFICIENT BOILERS
Boilers account for around 55 per cent of what we spend in a year
on energy bills, so an efficient boiler makes a big difference.
Replacing an old gas boiler with no controls, with an A-rated high-
efficiency condensing boiler and full set of heating controls will
significantly cut your home's carbon dioxide emissions.
Modern boilers are more efficient for several reasons, but their
main advantage is that they are all condensing boilers.
New hot water cylinders are factory insulated to help keep the hot
water at the right temperature for longer. They play an important
role in supplying us with readily available hot water, so it’s
important that they are fully insulated to prevent heat escaping.

7. 10/13/2019
WATER TUBE BOILER
 It is boiler in which water circulates in tubes heated externally by
the fire.
MECHANISM
• Fuel is burned inside the furnace, creating hot gas which heats
water in the steam-generating tubes.
• he heated water then rises into the steam drum.
• saturated steam is drawn off the top of the drum.
• Cool water at the bottom of the steam drum returns to the
feedwater drum via large-bore 'downcomer tubes', where it pre-
heats the feedwater supply.
A significant advantage of the watertube boiler is that there is less
chance of a catastrophic failure.

8. 10/13/2019
Owing to their superb working properties, the use of watertube
boilers is highly preferred in the following major areas:
• Variety of process applications in industries
• Chemical processing divisions
• Pulp and Paper manufacturing plants
• Refining units
The older fire-tube boiler design – in which the water surrounds the
heat source and the gases from combustion pass through tubes
through the water space – is a much weaker structure and is rarely
used for pressures above 2.4 MPa.

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WATER TUBE BOILER

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RECUPERATOR
Recuperators are simple & effective devices for reducing energy
consumption in Fuel Fired Furnaces.
The outgoing Flue Gases from the Furnace is used to preheat the
Combustion Air being supplied to the Burner & this results in
Energy Saving.
The exact amount of Preheat and the percentage of energy saved
will vary from installation to installation but on an average 10 to 15
percentage energy saving is easily possible by preheating Air to
approximately 300 Deg.C.
The payback period for the Recuparetor is usually less than one
year.
In heating, ventilation and air-conditioning systems, HVAC,
recuperators are commonly used to re-use waste heat from exhaust
air normally expelled to atmosphere.

11. 10/13/2019RECUPERATOR

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TYPES OF RECUPERATOR

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RECUPERATOR
Applications of recuperator:
• Reheating furnaces
• Heat treatment furnaces
• Higher flame temperatures
• Ceramic kilns
• Rotary melting furnaces
• Leaf spring heating furnaces
• Sodium Silicate melting furnaces
• Non ferrous melting furnaces
• Any other application where waste gases leave heating systems

14. 10/13/2019
COGENERATION
 It is the use of a heat engine or power station to simultaneously
generate electricity and useful heat.
A cogeneration system is the sequential or simultaneous generation
of multiple forms of useful energy (usually mechanical and thermal)
in a single, integrated system.
CHP systems consist of a number of individual components –
prime mover (heat engine), generator, heat recovery, and electrical
interconnection – configured into an integrated whole.
Cogeneration is a thermodynamically efficient use of fuel. In
separate production of electricity, some energy must be discarded
as waste heat, but in cogeneration this thermal energy is put to use.
Cogeneration systems linked to absorption chillers use waste heat
for refrigeration.

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COGENERATION

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COGENERATION
Benefits of cogeneration:
• Increased efficiency of energy conversion and use
• Lower emissions to the environment, in particular of CO2
• In some cases, biomass fuels and some waste materials are used.
• Large cost savings
• High efficiency, less transmission losses and increasing flexibility in
system use, if natural gas is the energgy carrier.
• An opportunity to increase the diversity of generation plant

17. 10/13/2019
HEAT ABSORBING GLASS
Heat-absorbing glass windows selectively reduce the transmittance
of visible light relative to solar energy. Using this glass in
replacement windows may result in energy savings.
Some of the absorbed heat can pass through the window through
re-radiation and conduction.
It contains chemicals that react to heat.
This reaction causes the energy to be absorbed rather than
transmitted through the glass or deflected by the glass.
These windows generally have a bronze, gray, or bluish tint and can
reduce brightness and glare which allows them to absorb the heat
that would otherwise transfer through the window.
Heat absorbing glass windows offer energy efficiency, safety and
security, ultraviolet protection, no mirror appearance, privacy and
design versatility.

18. 10/13/2019
Makes walls, ceilings, and
floors warmer in the winter and
cooler in the summer.

19. VENTILATION

20. Why ventilate?
Definition
• Ventilation rate is the rate at which air within a building is
replaced by fresh air. It may be expressed as:
Number of times the volume of air within a space is changed in
one hour (air changes per hour or ach).
Rate of air change in volume and time, e.g. litres per second (l/s).
• Ventilation is necessary to provide a healthy and comfortable
internal environment for the building’s occupants.
• The main task of ventilation is to remove polluted indoor air from
a building and replace it with ‘fresh’ outside air.
• Ventilation can also serve other roles – for instance, to provide an
air supply to open-flued combustion appliances and to form part
of an integrated strategy to provide thermal comfort and control
summertime over-heating.

21. Ventilation - Exhaust Only Fan,
Bath Fan or Range Hood
Ventilation - Supply Only
Ventilation - Balanced System with
Heat/Energy Recovery

22. Energy efficiency savings in ventilation
• There are two main ways in which ventilation ‘uses up’ energy. The major
one is the continual need to heat up the incoming air (during the heating
season) and its subsequent loss as it leaves the building via the purpose-
provided openings and air leakage. In addition, any form of mechanical
ventilation requires electrical power to operate.
• Improving airtightness
Air leakage is the uncontrolled movement of air, both
Into and out of the building, through the cracks and
gaps in the building envelope.
• Ventilation system design
The energy efficiency of the ventilation system can be improved, where
applicable, by employing heat recovery devices, efficient types of fan
motor and/or energy saving control devices in the ventilation system.

24. VENTILATION STRATEGIES
• There are three basic ventilation strategies—natural ventilation, spot ventilation, and whole-
house ventilation.
• NATURAL VENTILATION
Natural ventilation is the uncontrolled air movement in and out of the cracks and small
holes in a home. In the past, this air leakage usually diluted air pollutants enough to
maintain adequate indoor air quality. Today, we are sealing those cracks and holes to make
our homes more energy-efficient, and after a home is properly air sealed, ventilation is
necessary to maintain a healthy and comfortable indoor environment.
• SPOT VENTILATION
Spot ventilation can improve the effectiveness of natural and whole-house ventilation by
removing indoor air pollution and/or moisture at its source. Spot ventilation includes the use
of localized exhaust fans, such as those used above kitchen ranges and in bathrooms.
• WHOLE-HOUSE VENTILATION
The decision to use whole-house ventilation is typically motivated by concerns that natural
ventilation won't provide adequate air quality, even with source control by spot ventilation.
Whole-house ventilation systems provide controlled, uniform ventilation throughout a house.

25. Equipments
 Good ventilation is essential - it gives you fresh air and also helps protect a building against
damp and condensation. Unnecessary ventilation can waste energy and cost you a lot of
money. For example, ventilation accounts for around 30% of heat loss in most commercial
buildings (an estimated 25% in industrial buildings).
1. Motors
When buying new motors, always specify higher efficiency motors as they will save you up to
5% on energy costs, for little or no extra capital cost.
2. Fans
Variable speed fans can slow down when ventilation demands decrease. This will save
money on electricity as well as reducing heating/cooling costs. See Motors and Drives for
more
3. Time settings
Make sure fans aren't running when they're not required. This not only wastes energy, but
also removes heat from the building.

26. REFRIGERATION AND AIR-CONDITIONING

27. Refrigeration is the process of removing heat at a low temperature level and rejecting
it at relatively higher temperature level.
Refrigeration is accomplished by various methods, such as vapour compression systems,
absorption system and steam jet refrigeration cycle.
The most commonly used systems are the vapour compression and absorption systems.
further, even out of the above two, the vapour compression system is more widely used.
The items required for the make-up of a complete refrigeration and air conditioning
system are refrigerating equipment,fans,pumps,cooling towers,filters,air handling
units, and ducting.

28. Vapour Compression Systems
Features:
fig.1
Absorbing heat by the evaporation of a liquid refrigerant in the evaporator at a
controlled lower pressure
Raising the pressure of the low-pressure vapour coming from the evaporator, by using
the compressor

29. Removing heat from the high pressure vapour in the condenser so as to liquefy or
condense the vapour
Reducing pressure of the high pressure liquid to the level needed in the evaporator by
using the throttling device.
Reciprocating compressors are commonly used up to capacities of 120 TR, Screw
compressors are available for refrigeration capacities from about 150 TR to 750TR and
Centrifugal compressors are available for capacities from 150TR to very large sizes.
(Note: A new development has been arrival of scroll compressors, which are available in
the lower range capacity of up to 30TR.)
(Note: The efficiency of vapour compression does not depend upon on the compressor
alone. The compressor will work efficiently only if heat exchangers,i.e.,the evaporation
chiller and the condenser, operates efficiently.)

30. Vapour Absorption Systems
The vapour absorption refrigeration system is a heat-operated system. In this system
also, two pressure levels(evaporating and condensing pressure levels) are to be created.
In this system, the compressor is replaced by the combination of ‘absorber 'and
‘generator'. A solution known as the absorbent, which has an affinity for the refrigerant
used,is circulated between the absorber and the generator by a solution pump.
Fig.2

31. •The absorbent in the absorber draws the refrigerant vapour formed in the evaporator to
enable the refrigerant to evaporate at low temperatures.
In the generator, the absorbent is heated, thereby releasing the refrigerant
vapour(absorbed in the absorber)as a high pressure vapour, to be condensed in the
condenser. Thus the suction function of the compressor is performed by the absorbent in
the absorber and the generator performs the function of compression and discharge.
The absorbent solution carries the refrigerant vapour from the low(evaporator-
absorber)to the high side(generator-condenser).The liquified refrigerant flows from the
condenser to the evaporator because of the pressure difference between the two
vessels,thus establishing circulation of the refrigerant through the system.

32. Comparison of Vapour Compression Systems & Vapour
Absorption Systems
In the absorption system, except for two small electrically operated centrifugal pumps,
there are no moving parts.
Hence, the absorption system has no vibration and does not need heavy foundation as
required in vapour compression system.
For the absorption machine,the capacity control is stepless whereas in the vapour
compression system,the capacity control operates in certain steps.
The vapour absorption system can be operated on waste heat.
No-recharging cost of the refrigerant in the absorption system,which will be quite
substantial and inevitable in the vapour compressor machine.
Working pressure are very low for the absorption cycle.

33. Since electrical power is required for small pumps,the electrical switchgear required is of
small capacity compared to the vapour compression system.The starting current
requirement in absorption system is also low.
The COP of the absorption system is very low(around 1.1 for 2-stage lithium bromide
machines)compared to the vapour compression system(4 or 5)for air conditioning
applications.
The absorption system becomes competitive only if the electricity to the fuel price ratio
is greater than four.
The heat rejection factor for the vapour absorption system is high(2.5 as compared to
the vapour compression around 1.2).The cooling tower and pump condenser circulating
pump capacity have to be proportionally higher.
The life span for the absorption system is less compared to vapour compression system
because of the corrosive nature of the lithium bromide solution.

34. Measurements:
The performance of a given system depends upon:
Inside and outside design conditions
Measured flows and capacities of all equipments,used in the system
Comparison of the measured and design capacities
Comparison of energy consumption with the design values

35. To measure and evaluate capacities, following instruments used:
Measuring Quantity Unit Instruments
Air Flow m/s(velocity) Manometer or vane/hot-
wire anemometer
Water Flow Pascal or KN/m(pressure) Portable non-intrusive
ultrasonic flow meter
Rotation/speed m/s Stroboscope
Non contact type
electronic technometer
An odometer
Temperature DBT,WBT Sling psychourometers
Electronic thermo
hygrometers
Electrical parameters Voltage,current,power,
power factor
Clamp on type portable
power masters

36. Energy Efficiency Ratios:
The performance of refrigeration cycle is usually described by the COP.It is defined as
the ratio of amount of heat removed divided by the required energy input to operate the
cycle,or
In the air conditioning industry,the EER is generally used measuring the refrigeration
effect in BTU/hour and the work done in watts.
(Note: The higher the COP or the EER the better its efficiency.)

37. Another useful merit is
(Note:A lower value of specific power consumption implies that system has better
efficiency.)

38. Energy conservation opportunities:
Installations of variable speed drives at AHU fan motors
At cooling tower fan motors
At secondary chilled water pumps
Low leakage dampers
Reduced minimum outdoor air
Unoccupied ventilation reduction
Enthalpy control/dry bulb economizer
Exhaust air control
Retrofit of central fans for variable air volume usage
Heat recovery system

39. HIGH TEMPERATURE COOLING SYSTEMS

40. INTRODUCTION
The High Temperature Cooling System is a revolutionary
method to optimize the power input by reusing the
thermal benefits of return chilled water from core
system.
Phenomenon:
Chilled water supply temperature is higher about 13-15 ºC, which in turn
reduces the cooling load of chiller and when used with a core or centralized
system.
These can work in following two ways according to the system.
 The return chilled water is used for cooling by mixing it with fresh
chilled water supply to get the desired chilled water supply
temperature.
 The return air is mixed with fresh air coming from the centralized or
core system to get the adequate room temperature with required
fresh air

41. COMPARISON WITH CONVENTIONAL SYSTEMS
PARAMETER
High Temperature
Cooling Systems
Conventiona
l Systems
Remarks
Chilled Water
Temperature
Difference
13 to 15 Degree C 6 to7 °C
Chiller and cooling system
load reduction
Cooling might save 30% of overall
cooling energy, as comparing to
conventional all-air VAV system,
result mainly from reductions in
energy used to remove sensible heat
Thermal Energy
Transportation
Medium
Water Air
Thermal Energy by
pumping water can be less
than 5% of that required to
move the same amount of
thermal energy with fans
Cost
Lower First-Cost
Comparatively
high
Lower Energy Consumption
Best Peak Saving
Least Maintenance
Requirement

42. TYPES OF
HIGH TEMPERATURE COOLING SYSTEMS
1. RADIANT COOLING SYSTEMS
2. CHILLED BEAMS (Metal Convective Panels)
3. COOL GRIDS (Plastic Capillary tubes in Plaster)

43. TYPES
1. RADIANT COOLING SYSTEMS
2. CHILLED BEAMS (Metal Convective Panels)
3. COOL GRIDS (Plastic Capillary tubes in Plaster)

44. RADIANT COOLING SYSTEMS
A radiant cooling system refers to a temperature-controlled surface that cools indoor
temperatures by removing sensible heat and where more than half of heat transfer occurs
through thermal radiation.
Radiant cooling systems are usually hydronic, cooling using circulating water running in
pipes in thermal contact with the surface. Typically the circulating water only needs to
be 2-4°C below the desired indoor air temperature. Once having been absorbed by the
actively cooled surface, heat is removed by water flowing through a hydronic circuit,
replacing the warmed water with cooler water.
TYPES:
While there are a broad range of system technologies, there are two primary types of
radiant cooling systems.
• The first type is systems that deliver cooling through the building structure, usually slabs,
these systems are also named thermally activated building systems (TABS).
• The second type is systems that deliver cooling through specialized panels. Systems using
concrete slabs are generally cheaper than panel systems and offer the advantage of
thermal mass while panel systems offer faster temperature control and flexibility.

45. SLAB
Radiant cooling from a slab can be delivered to a space from the floor or ceiling.
Since radiant heating systems tend to be in the floor, the obvious choice would be
to use the same circulation system for cooled water.
Advantages:
• First, it is easier to leave ceilings exposed to a room than floors, increasing the effectiveness of
thermal mass. Floors offer the downside of coverings and furnishings that decrease the effectiveness
of the system.
• Second, greater convective heat exchange occurs through a chilled ceiling as warm air rises, leading
to more air coming in contact with the cooled surface. Cooling delivered through the floor makes the
most sense when there is a high amount of solar gains from sun penetration, as the cool floor can
more easily remove those loads than the ceiling.
• Chilled slabs, compared to panels, offer more significant thermal mass and therefore can take better
advantage of outside diurnal temperatures swings.
• Chilled slabs cost less per unit of surface area, and are more integrated with structure.

46. PANEL
Radiant cooling panels are generally attached to ceilings, but can be attached to
walls. They are usually suspended from the ceiling, but can also be directly
integrated with continuous dropped ceilings. Modular construction offers increased
flexibility in terms of placement and integration with lighting or other electrical
systems.
Advantages:
• Lower thermal mass compared to chilled slabs means they can’t easily take advantage of passive
cooling from thermal storage, but controls in panels can more quickly adjust to changes in outdoor
temperature.
• Chilled panels are also better suited to buildings with spaces that have a greater variance in cooling
loads.
• Perforated panels also offer better acoustical dampening than chilled slabs.
• Ceiling panels are also very suitable for retrofits as they can be attached to any ceiling.
• Chilled ceiling panels can be more easily integrated with ventilation supplied from the ceiling.
• Panels tend to cost more per unit of surface area than chilled slabs.

47. CHILLED BEAM (METAL CONVECTIVE PANELS)
A) PASSIVE
Passive chilled beams consist of a cooling coil with fins and housing that is suspended
from the ceiling (Figure 1). Chilled water passes through the coil at temperatures
typically from 55°F to 63°F (13°C to 17°C),3,4,5 cooling the air around the chilled
beam and causing it to descend toward floor level. Passive systems have design sensible
cooling capacities of approximately 5.6 W/ft2 to 6.5W/ft2 (60 W/m2 to 70 W/m2) of
ceiling area covered by chilled beam units.
Fig.-1 Passive Chilled Beam
Source: Emerging Technologies Article_204559

48. B) ACTIVE
Active chilled beams, also known as induction diffusers,3 are more complex than passive
chilled beams (Figure 2). In addition to a finned cooling coil, they have an integral air
supply designed to meet minimum outdoor air (OA) requirements (e.g., ANSI/ASHRAE
Standard 62-2001, Ventilation for Acceptable Indoor Air Quality). In this way they differ
from fan-coil units, which blow indoor air over cooling coils located in the conditioned
space and rely upon a separate system to meet OA requirements. The supply air passes
through nozzles, inducing additional airflow from the conditioned space through the
cooling coil and down to the conditioned space. Due to forced convection, active
chilled beams achieve cooling densities about twice (e.g., 12 W/ft2 to 14.8 W/ft2
[130 W/m2 to 160 W/m2]1) those of passive chilled beams.
For this reason, we focus on active chilled beam systems.
Fig.-2 Active Chilled Beam
Source: Emerging Technologies Article_204559

49. COOL GRIDS (PLASTIC CAPILLARY TUBES IN PLASTER)
Cooling grids made of capillary tube placed closed to each other, can be imbedded in
plaster, gypsum board or mounted on ceiling panels. This system provides an even
surface temperature distribution. Due to the flexibility of the polypropylene tubes,
cooling grid might represent the best choice for retrofit or new applications. The heart
and center of the capillary system is the capillary mat. This is a mesh of conduits,
with a diameter of just 1/16" (2mm) through which water is circulated into collecting
pipes. Capillary mats are extremely flexible so that they can be installed in convex
ceilings or around a column. Capillary mats can be imbedded into walls, ceilings, and
floors. They transform these parts of your building into heating and cooling surfaces,
which can be regulated easily.

50. Illustration:
Capillary tube cooling can be switched on quickly. After a few minutes, the capillary ceiling begins to
cool the room effectively. This is brought about by the very small amount of water in the capillary
tubes and the positioning of the mats close to the surface. In addition, the capillary ceiling is able to
regulate itself easily. The illustration below shows how quickly the temperature changes.

51. INSTITUTE OF RURAL RESEARCH AND
DEVELOPMENT
IRRAD is an initiative of the S M Sehgal Foundation,
registered as a Trust since 1999 to further the wellbeing of
rural communities in India.
RADIANT SLAB SYSTEM IN
IRRAD- PHASE 2

52. INTRODUCTION
The proposed campus of Institute of Rural Research and Development, Gurgaon is the
headquarters of The Sehgal Foundation Group. This group is a non-governmental
Organization rendering to the development of the rural population all over the country.
With the prime initiative of the owner, the campus has been designed and constructed as
per the norms & regulations laid down by the Indian Green Building Council for Green
Buildings. The project has aimed to achieve a ‘PLATINUM’ rating as per the credits for
“Core & Shell” buildings.
Total area of the block is 19,697 Sq. ft. & total conditioned area is 13,621 Sq. ft.
There are total 2 nos of TRANE make chillers of which one is 150 TR & another is 80 TR
each has been installed at site. From the 2 chillers only 1 will work at a time & other will
be stand-by. These chillers are the water cooled chillers.
A Radiant cooling system is also used in the Phase 2 block which is separately & specially
designed. This Block has Ground + 4 floors & each floor plate has approx. 3000 Sq. ft. air
conditioned area. This block uses a new technology called as Radiant cooling system.

53. 53
HVAC SYSTEM DESCRIPTION
In IRRAD, each air conditioned space is getting catered by a hybrid approach of
air conditioning, composing of two different sets of Air-Conditioning Systems,
namely, the Radiant Slab and the Air Handling Unit (AHU).
These equipments have been installed to counter different loads.
• The Radiant Slab counters the Sensible Load and
• The AHU counters the Latent Load.
This composition of two different cooling systems results minimizing the cooling
loads of the building by addressing the two different forms of heating loads more
distinctly, thus maximizes the comfort while avoiding the significant energy use
and operating costs of air round conditioning.
Each floor has a different set of Air Handling Unit and the Radiant Slab serving
the Latent and Specific loads respectively on that floor only.

54. The Phase II block used a separately & specially designed technology called as
Radiant Cooling system. In this system chilled water pipes were casted in the
ceiling at each floor. Water returning from AHU is circulated in these pipes
through two separate pumps called as Radiant Cooling Pumps. The
temperature of Water flowing through these pipes is controlled by a 3-way
modulating valve.
RADIANT COOLING SYSTEM

55. Heating & Ventilation Air conditioning systems:
High Side Systems:
• 1. Water cooled chiller : ( 80 TR )
• 2. Primary pumps : ( 2 Nos)
• 3. Condenser Water pumps : ( 2 Nos)
• 4. Secondary Pumps : ( 2 Nos)
• 5. Radiant cooling Pumps : ( 2 Nos)
Low Side Systems:
• 1. Air Handling Units : ( 05 Nos)
• 2. Exhaust/ Ventilation Fans : ( 06 Nos)
• 3. Jet Fans : ( 02 Nos)
• 4. Radiant Cooling : ( 02 Nos)

57. HIGH SIDE
This system consists of installing a new 80 TR screw chiller and its
advantages are as follows:
(i) The average block load of both phase I & II is estimated at 65 to 75
TR which can be met efficiently by 80 TR chiller, Incase if the load
increases then the 150 TR chiller can be operated.
(ii) In case of breakdown of 150 TR chiller 80 TR capacity is available
to take care of both the buildings.
(iii) As 80 TR machine comes with single/dual compressor the effective
use of one compressor 40 TR can be done in the night time for
cooling radiant slab & cooling of guest rooms also by circulating
fresh air with heat recovery. This will give maximum operational
efficiency due to lower night temperatures.

58. LOW SIDE : Radiant cooling
This system consists of running chilled water pipes embedded in the
ceiling slab. Sensible load cooling using radiant chilled water pipes
in the slab operating at 15– 19degC differential chilled water temp
& latent load using Air handling unit operating at 6.6 – 12.2degC
differential chilled water temp. 6.6 deg C chilled water shall be
produced by chiller and 15 deg C chilled water shall be produced by
using Heat exchanger having input water at 6.6 deg C from the
chiller.

59. According to the results, in loop-1 and 2, the chilled water inlet temperature
range is about 11.2°C to 20.8°C while the chilled water outlet range is
17.6°C to 20.8°C.

60. CONTROLS
Monitoring Parameters
• Slab Temperature Monitoring, 2 nos per slab & 1 no for terrace
Floor Slab.
• Room Temperature Sensor, 2 nos per slab & 1 no for terrace Floor
Slab.
• Room Humidity Sensor, 2 nos per slab & 1 no for terrace Floor Slab.
• Common Header Temperature in Radiant Piping system.
Controlling Parameters
• Modulation of Mixing Valve installed on the common Header
Radiant Header.
• Controlling of Re-circulating for Radiant Cooling System.

61. Bibliographical References:
1. Teri handbook on energy audits and management
2. Articles by Devki(1999)
3. Articles by Ananthanarayanan (1998)

62. THANK YOU