MECHANICAL SYSTEMS
POR T F O L I O
COURSE COORDINATOR: SHOUMIK DESAI
NAMRATHA GOPAN I NU17UAR014 I SEM 8 I NITTE INSTITUTE OF ARCHITECTURE
CONTENTS
01 02 03 04 05
Time problem – Outlining the Passive Strategies for Ladakh Psychrometric charts Description of Passive Strategies
Cooling Systems
Chilled Water Systems Radiant Cooling Air Economizer Air Handling Unit Air-Water System Fan Coil System
Single Line Diagrams of Cooling Systems Chilled Water and Radiant Cooling System Fan Coil System
Elevators and Escalators Types of Elevators Escalators and Walkalators Fastest Elevators in the World
Questionnaire Questions Answer Key
1-2 3-5
7-8 9-10 11-12 13-14 15-16
18 19
21-31 32-37 38-39
41 42-44
ASSIGNMENT 1
Time problem – Outlining the Passive Strategies for Ladakh
PSYCHROMETRIC CHART
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JANUARY
FEBRUARY
MARCH
MAY
JUNE
JULY
AUGUST
SEP TEMBER
OCTOBER
NOVEMBER
DECEMBER
MECHANICAL SYSTEMS | SPRING 2021 | SEM 8
APRIL
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S T R AT E G Y D E S C R I P T I O N S - L E H L A D A K H January
February
Strategies
Active solar heating
Passive solar heating Active solar heating Internal gains
Howto Achieve
Radiant floors Ventillation preheating Radiant floors Insulation in Ventillation ceiling, outer preheating walls and floors Trombe wall
March
April
May
June
Active Heating Solar Passive Solar heating Internal Gains
Passive solar heating Active Solar Internal gains Internal Gains Natural ventilation Mass cooling
July
August
Internal Internal Internal gains gains gains Natural Natural Natural ventilation ventilation ventilation Mass cooling Mass cooling Mass cooling
September October
November
December
Passive Active solar Active solar Active solar solar heating heating heating Passive heating Passive solar Internal gain Passive solar solar heating heating Natural heating Internal gains Internal gains ventilation
Radiant floors Radiant floors Radiant floors Trombe walls Ventillation Trombe wall Ventillation Ventillation Thermal preheating Thermal Thermal mass in Radiant floors Trombe walls Thermal preheating preheating Thermal mass mass in Insulation in mass in walls mass in walls and floors Trombe wall Thermal mass Insulation in Insulation in in walls Stack walls ceiling, outer walls Ventillation in walls Stack Stack Bukhari ceiling, outer ceiling, outer ventillation Stack walls and ventillation preheating ventillation Stack (Heater) walls and floors walls and floors ventillation floors Trombe ventillation Radiant floors Trombe wall Trombe wall wall
Parameters Air Velocity (m/s)
0.2
0.2
0.2
0.2
0.2
0.15
0.065 to 1.6
0.065 to 1.6
0.065 to 1.45
0.065 to 1.3
0.065 to 1.25
0.065 to 1.5
Metabolic Rate (met)
1.75
1.5
1.35
1.35
1.4
1.4
1.4
Mean radiant temperature (°c)
20° to 25°
20° to 23°
20° to 23°
20°
20° to 16°
20° to 15°
20° to 15°
Clothing (clo)
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0.2
0.2
0.3
0.3
0.3
0.3
0.065 to 1
0.065 to 1
0.65 to 2.00
0.65 to 2.00
1.25
1.35
1.5
1.35
1.35
20° to 15°
20° to 18.5°
20° to 25°
20° to 25°
20° to 30°
0.065 to 0.9 0.065 to 0.9
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S T R AT E G Y S T R AT E G I E S January, February, March, April, October, November, December:
January, February, March, October, November, December:
RADIANT FLOORS
VENTILLATION PRE-HEATING
Radiant heating systems provide heat to interiors It consists of electric wires running under the floor surface Electricity is passed through these wires and heat is generated. The heat then transfers through the floor and heats up the room.
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Solar ventilation air preheating technology uses the energy of solar radiation to preheat ventilation air. The incident solar radiation falls on the perforated metal It is painted a dark colour to absorb maximum solar radiation
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S T R AT E G Y S T R AT E G I E S February, March, April, May, September, October, November, December:
May. June, July, August, September:
TROMBE WALLS
STACK VENTILLATION
Sunlight having shorter wavelength and high energy is allowed to pass through transparent layer. Hence heating the thermal mass and the radiated heat from thermal mass having long wavelength and low energy is trapped inside or is not allowed to escape outside. Glass, fibre or any transparent material 8 in. to 16 in. thick, coated with dark absorptive material and air cavity of ¾ in. to 6in. between wall and exterior transparent surface.
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Stack ventilation relies on the temperature difference between the air inside the building and the outdoors to drive the flow. Warmer air is lighter than colder air, hence it rises up The lighter hot air escapes through the opening and cold air enters from the lower window
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S T R AT E G Y S T R AT E G I E S February, October, November, December:
THERMAL MASS IN WALLS Thermal mass is the ability of a material to absorb and store heat energy. A lot of heat energy is required to change the temperature of high density materials like concrete, bricks and tiles. They are therefore said to have high thermal mass.
INSULATION IN CEILING Layer 1: Ladakhi roof starts with a ceiling of wooden beams, rafters and willow stick joists on which woven straw mats are placed Layer 2: Ladakhi “yagtses” grass Layer 3: Rough soil Layer 4: Markalak clay Final layer of soil is applied wet
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STORAGE OF MATERIALS ON THE ROOF FOR INSULATION
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ASSIGNMENT 2
Cooling Systems
C H I L L E D W AT E R S Y S T E M S WORKING Cooling tower
The refrigeration cycle starts where low pressure liquid water refrigerant enters the evaporation. The evaporation changes the low pressure liquid to low pressure gas c cool gas refrigerant. The cool refrigerants is passed to the compressor where the low pressure gas is compressed to high pressure gas(hot air). The hot refrigerant enters the condenser where the heat is released by the condenser and it cools down high pressure liquid. The hot refrigerant is passed through the expansion valve where the high pressure liquid is made to expand to low pressure liquid. The cool refrigerant then enters the evaporator and the cycle continues. Chiller
The hot water from the chiller is pumped to the cooling tower. The hot water is then sprayed to the fill. The hotwater cools down and become less hot. The cold water which is settled at the bottom of the tank is passed through a water pipe of the chiller. Exchange of heat takes place in the condenser where the hot refrigerant in the chiller transfers heat to the cold water from the cooling tower. Hence the hot refrigerant losses heat and become cold. The cold refrigerant is then passed to the expansion valve of the chiller. Air handling unit
Exchange of heat takes place in the evaporator. The hot water (in the water pipe) is made to pass through the evaporator where cold refrigerant is flowing in the opposite direction. Heat is transfer takes place and the hot water turns cold. The cold water is passed to the AHU further taken to the rooms. The return air is passed through a regulator unit to be taken to the hot coil supply. The hot water is then sent back to the water line.
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C H I L L E D W AT E R S Y S T E M S Chilled water system is used in hot and dry climate Applications Industries Petroleum refineries Manufacturing factories
Condenser
Condenser converts hot refrigerant gas to hot refrigerant liquid. The gas is condensed and heated to discharge liquid. Outdoor unit
COMPONENTS Evaporator:
Evaporator is the component which connects the liquid refrigerant to gas refrigerant. The liquid is expanded and it is cooled to a boiled temperature. Indoor unit
Expansion Valve Compressor
It connects outdoor and indoor unit using copper refrigerant tube. Low pressure gas(cold refrigerant) is compressed to high pressure(hot refrigerant) Outdoor unit
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Release the pressure from liquid refrigerant. The liquid expands to vapour. The high pressure liquid is cooled down to lower pressure( cold refrigerant liquid)
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RADIANT COOLING ENERGY RECOVERY WHEEL
RADIANT PANELS
EXHAUST FAN
Heat flows from hotter body to cooler body, There is constant heat exchange between the wall, roof,floor people and other object Water as a cooling medium, It has 4 times the heat absorbing capacity than air. Hence cooling by water is much efficient than cooling by air
COOLING COIL FRESH AIR SUPPLY FAN
SUPPLY AIR
ROOM
CONV PUMP
WORKING -Radiant cooling systems work by circulating chilled water through a network of polymer pipes installed in floors, walls or ceilings. -This network of pipes can turn the floors, walls and ceilings of a conditioned space into cooled surfaces that evenly absorb heat energy. -In this case, chilled water was produced in a radiant chiller and supplied to the radiant panels - A conventional chiller was used to feed chilled water to a cooling coil for dehumidification of air in the DOAS. In the DOAS, supply air first enters the energy recovery wheel, where it exchanges heat with return air and then enters the cooling coil.
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RETURN AIR
CONV CHILLER
RADIANT CHILLER PRIMARY PUMP
RADIANT COOLING SYSTEM OPERATED WITH CHILLER
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RADIANT COOLING C O M PO NENT S:
Radiant cooling system is used in climates from cold and dry to very hot and humid
Ra di a nt c ool i ng p a nel s
A PPLIC AT I O NS: Commercial Area – office spaces, schools, and few applications in hotels. Residential – in homes, in areas where humidity is less. Industry Hospitals and Laboratories – Radiant cooling can be effective to maintain a clean envi-
Radiant cooling panels are panels with integrated water pipes and they are fixed to building construction by hangers. While both ceilings and walls can be used to attach radiant panels. The radiant panels are usually designed as small modular units set into a metal frame substructure
ronment in hospitals and laboratories. High Temperature Hgh Pressure Vapor
COMPRESSOR
Low Temperature Low Pressure Vapor
C H I LLER
Chiller is used to cool the fluid medium to required temperature. Exchange of heat takes place in the condenser where the hot refrigerant in the chiller transfers heat to the cold water.
CONDENSER
EVAPORATOR
CHILLED WATER RETURN
High Temperature Hgh Pressure Liquid
EXPANSION VALVE
CHILLED WATER SUPPLY
PI PES
Low Temperature Low Pressure Liquid + Vapor
Loops of cross linked polyethene pipes are embeded in walls/floors/ceilings etc and chilled water is passed through it
FAN
OUTDOOR AIR EW EXHAUST AIR
COOLING COIL
CHILLED WATER CEILING RADIANT COOLING PANNEL
SW
FAN ENTHALPY WHEEL
SENSIBLE WHEEL
ROOM
M ANI FO LD
A manifold is a device connecting water pipes in an underfloor heating and cooling system. the manifold is responsible for distributing and collecting the heat medium and regulating the flow of each loop.
R ADI ANT CO O L ING S Y S T EM O P ERAT ED W IT H C HI LLER 30/4/2021
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AIR ECONOMIZER Out d oor air e c o no mi ze rs can re du ce t he o p e rat in g co s t of c ool i ng i n m ost c l i m a t es . They a r e ge ne rall y av ail able as fact o r y o p t io n s o r acce s s or i es w i t h r oof - m ou nt ed u ni t s. Wit h an outdo o r air e c o no miz e r, re t u rn air is e it he r re t u rn ed t o t h e su p p l y a i r sy st em or ex h a u st ed t o a t m os p h er e, a s dete rmin e d by t he r elat iv e dr y-bulb te mp e rat u re o f t he re t u rn air an d t h e ou t door a i r bei ng p r ov i ded t o t h e bu i l di ng .
PARTS:
A plenum is a cavity within the pressure envelope that is below a room Return air is the portion of the supply air that is recirculated to the cooling/heating apparatus after being collected by the return grilles in the zone. Return damper is sized to provide the supply air flow less the required minimum outdoor air flow Outdoor air and relief dampers are sized to pass the full required cooling supply air flow Fan is provided for movement of air into the dampers.
Reference:
ASHRAE. (2019) Heating, Ventilating and Air-Conditioning Applications-ASHRAE Handbook [pdf] Dougharty, F. (2012) Air Side Economizer design using psychrometric analysis [pdf] 30/4/2021
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AIR ECONOMIZER
SC HEMAT I C LI NE D IA G R A M O F A N A IR - S ID E E C O NO M I Z ER
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WO RKI NG O F EC O NO M I ZER
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AIR HANDLING UNIT A IR H ANDLING UNIT
An air handler, or air handling unit, is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning HVAC system. LOCATION: industrial,commerical PARAMETERS: Temperature Humidity Air Movement Air Cleanlines SPACE : Basement, Roof,Floor, or mixture of all. COMPONENTS: 1.GRILLS:
Protection from entering unwanted substance into mechanical components.
2.DAMPERS:
Multiple sheets of metal which can rotate Regulates air flow
3.FILTERS:
Large particles panels and pre filters Small particels bag filters Pressure sensors
4.COOLING AND HEATING COIL: Heating and cooling as per Set point
Coolent or refrigirent Steam or hot fluid
5.FAN COMPONENT: Pulls air and pulls out into dampersand into filter.
Centrifugal,ec fans Pressure sensors to control pressure in duct
6.SENSORS:
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AIR HANDLING UNIT W O R KING:
Air handling unit collects the external or air from the room which takes in through filters by grills and dampers which regulates the flow of air into the unit.Air is passed through filters, that filters dust in different sizes,these are with pressure sensors that are used to indicated air pressure into the unit and if filters are dirty it can be changed accordinly to maintain the pressure.To provide comfortable temperature int the required space the air has to treated by colling or heating systems depending on the air condition.coolents in cool coil is passed through to cool the air in order to reduce the temperature of air,instead heating coil with steam or hot fluid is used to heat uop the air in cold conditions.In extreme cold contions preheaters are used to heat up the air.And in dry areas humidifier with spray of mist is used to cool the air in outlets.air cooling down exchanges heat,which might cause in drops of water which leads to have drainnpan under the cooling coil.Incase of heat circulating coil is used to use the waste heat in heating coil making it energy efficient.further the air passes through fan which brow throgh the conditioned air into filter and into the duct.
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A I R - W AT E R S Y S T E M , FA N C O I L S Y S T E M Fan coil system is a device consisting of heating and cooling coil and fan. Generally it is not connected to a ductwork and is used to control temperature space in multiple spaces. It is controlled either manual on/off switches or by thermostat. The units may stand alone or to be ducted for multiple spaces. Fan coil units are typically selected and sized to heat and cool a small zone with specific load requirements. Ther e ar e two t ype s o f fan co ils : T wo piped fan c o il : Consisting of one return and one supply pipe. The supply pipe supplies hot or cold water according to the time of the year. F our piped fan c o i l: Consisting of two supply and two return pipes. It allows hot or cold water to enter at any given time. Due to requirement of different temperatures at
different spaces, there is difference in heat gain or heat loss and hence four piped fan coils are used.
F.C.U: The fan coil unit consists of a filter, Fan sections, motor, heating and cooling coils. It is the main component of the whole system.
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A I R - W AT E R S Y S T E M , FA N C O I L S Y S T E M P rocess:
C O M PO NENT S
In the AHU duct, consisting of two pipes; return duct and fresh air, both of which are connected to the building for easy return and supply of air. The fresh air enters into the FCU through the duct. The air passes through the filter, wich then is pushed at a certain pressure into the coil area. According to the requirement, the air is cooled or heated before passing into the diffusers. The air that is used up or heated, either mixes with the fresh air and reenters the FCU or returns to the atmosphere through the return duct. The four pipe fan coil system is used in for heating or cooling rooms or spaces in residential,
FI LT ERS:
Filters made up of Merv rating 5-7 Catches more dust particles up to 70%. C O I LS:
The coils are made up of galvanized steel. These coils provide the necessary condensation and convection processes carried out for the system. FAN:
It is used to push the fresh air into the FCU further into the coil area to cool or heat the water to pass it n in the diffuser. and industrial buildings.
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ASSIGNMENT 3
Single Line Diagrams of Cooling Systems
AIR HANDLING UNIT
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AIR HANDLING UNIT
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ASSIGNMENT 4
Elevators and Escalators
E L E VAT O R S HYDROULIC ELEVATORS
Adv a nt a ges
Quicker to install Less expensive to install Occupy less space in a building Option to have machine room-less configuration
T w o t ypes :
1 . Traction 2 . Hydraulic
Compon en ts
D i sa dv a nt a ge
H y dr aulic p o we r unit
Reduces the noise and vibration A silencers is attached to the motor which reduces the transmission of pulsations from the pump to car P i st on
Cannot be used in high rise buildings as they need more energy to raise the car- low or mid raised buildings Maximum travelling limitation- 45m
The cylinder is fixed with a thick steel piston which moves the car when pressure is applied. S uspen ded syste m
The car cage is suspended from a wire cable W o r k in g
-piston at the bottom of the elevator that pushes the elevator up -The elevator cab is lifted by an electric motor that pumps oil into the cylinder to move the piston. -To lower the car, the valve is opened which sends back the fluid to the fluid reservoir.commercial and industrial buildings.
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E L E VAT O R S WORKING OF HYDROULIC ELEVATORS
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E L E VAT O R S PATERNOSTER LIFT A lift system that moves continuously in one direction by providing the same car lift. Provide the movement of up and down continuously. Suitable for 6-7 floored buildings There are multiple cordless elevators which rotates through a single shaft.
Adv a nt a ges
smaller shafts decrease in wait times Less electricity consumption
C o mpon en ts
D i sa dv a nt a ge
B e lt / chain
Cost is more Not suitable for children and old people Safety issues
The cars and the chain move in a loop over a driven chain wheel. C ar
The car is attached to the driven wheel by brackets The car are constrained by vertical tubular guide in which the cars engage in two each side. To give stability the cars have a steel bow underside W or k in g
-Work due to magnetism and linear motor technology. -Magnetic levitation is a result of electromagnetism and linear motor technology -There is interlocking exchange system in the tracks of the elevator shaft -Linear motors are used to move the cars through the shafts of ropeless elevator.
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E L E VAT O R S
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E L E VAT O R S ELECTRIC LIFT
Adv a nt a ges
Electric lifts are faster than their hydraulic counterparts. It makes sue of counterweight for movement and also features batteries. It makes use of sheaves and cables for the movement. Compon en ts El ect r ic mo to r
It is selected according to the size and capacity of the life. The electric motors send signal which controls the motion of the elevator S uspen ded syste m
lower electricity consumption; low operating costs the lack of polluting materials It has the ability to continue to operate even in the event of an interruption in the supply of electricity Less space required D i sa dv a nt a ge
construction cost is more
The car cage is suspended from a wire cable W o r k in g
-These are handled by operating winch. -Elevator is connected to a very tough metal rope -The tough metal rope passes through a sheave on the elevator in the engine room. -Electric traction lifting machine which provides to transmit the movement of ascent or -descent to the ropes that connect the cabin to a counterweight
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E L E VAT O R S
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E L E VAT O R S PNEUMATIC LIFTS Adv a nt a ges
They use compressed gas Open systems, allowing the air outside after use.
Light in weight Operating elements are cheap and easier to operate High output to weight ratio
C o mpon en ts A i r f ilt er s-
D i sa dv a nt a ge
They are used to the filter the contaminated air C o mpr essor-
Help is compressing the air. They are operated by electricity or diesel. A i r Cooler -
Use of compressed air is more expensive compared to electricity Exhaust air noise in unpleasant Weight to pressure ratio is high Works better only in lower pressure
During the compression process the temperature of air increases and hence its imported to cool it down El e ct r ic mo to r-
Converts electric energy to mechanical energy W or k in g
-The air coming from outside is pressurised inside the compressor. -This leads to the rising of temperature. Coolers make the air cooler which is then passed to storage reservoirs. -A pressure switch is connected to the electric motor which regulated the movement of elevator
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E L E VAT O R S
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E L E VAT O R S MACHINE-ROOM-LESS (MRL) ELEVATORS
Adv a nt a ges
low energy consumption require less space Lesser cost Faster car speed
Do not have a machine room above the shaft Travel distance- 165m Travel speed- 3mps Compon en ts
D i sa dv a nt a ge
D rive un it -
gearless mechanism with a permanent magnet synchronous motor Top in st a ll ati o n o f primar y e qu ip me n t -
prevent water from coming into the elevator shaft and being in direct contact with the drive unit and controller.
Greater initial cost Longer installation time Increased pit and overhead requirement Can be used only in mid-rise buildings
R oller guide s-
It rotates to provide smoother movement along the rail. Used in high speed elevators. Con t r ol Syste m W o r k in g
-The elevator cab is lifted by an electric motor(hoisting machine) -It pulls the elevated cab up and down -A counterweight is given in the other side of the pulley.
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E L E VAT O R S
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E L E VAT O R S TYPES OF LIFT
Hydraulic Elevators Travel distance-15m Travel speed- 1mps
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Machine-Room-Less (MRL) Elevators Travel distance- 165m Travel speed- 3mps
Pneumatic elevators
Electrical lift
Paternoster lift
Travel distance- 15m Travel speed- 1mps
Travel distance- 20m Travel speed- 0.8mps
Travel distance- 20m Travel speed- 0.3mps
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E S C A L AT O R S Escalators by design represents a moving staircase that transports people from a floor to another. They are electrically run by motors where the steps move on tracks. A handrail is provided for the escalators for supports along with an emergency button. Escalators were mainly built for easy access to different floors with time efficiency. P ar t s of esc alato rs:
1. Landing platforms: This platform consists of the gears and motors below them while acting as a platform. The upper portion contains the motor and the main drive gear and step return idler sprockets. 2. Truss: the hollow portion that holds the lower and upper landings 3. Tracks: It is a system that guides the step chain. There are two tracks for both the front wheels and the back wheels. 4. Steps: solid stainless steel or aluminum blocks painted with yellow on the edged for the demarcation. 5. Handrail: Providing the hand hold for the passengers.
1. Emergency stop button 2. step motion safety device 3. overload detection device 4. speed governor
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5. electromagnetic brake 6. drive chain safety device (dcs) 7. handrail speed safety device 8. steps
9. main drive sprocket 10. auxillary brake
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E S C A L AT O R S There are four main types of escalators mainly; 1. Parallel 2. Criss-cross 3. Multiple parallel 4. Curved
Parallel This type of escalators is a combination of two standard escalators placed side by side that either move in opposite directions or same direction. Commonly this type of escalators are seen in malls, metro stations, large offices, airports and other public buildings. Details: Speed: 0.5m/s Inclination : 30 or 35 Step widths : 800-1000mm Materials: Handrail : rubber/stainless steel Tread: stainless steel Landing plate: anti skid stainless steel
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E S C A L AT O R S Criss-cross They are stacked standard elevators going in only one direction per escalator facing towards each other. Commonly seen in malls and shopping centers for aesthetics. Details: Speed: 0.5m/s Step widths : 600 / 800 / 1000mm Materials: Handrail : rubber/stainless steel Tread: stainless steel Landing plate: anti skid stainless steel
Multiple parallel: This type has more than one escalator placed next to each other in one direction with the same bank that travels in the other direction. Details: Speed : 0.5m/s Step widths : 800 / 1000 Inclination 30 / 35 Materials: Handrail : rubber/stainless steel Tread: stainless steel Landing plate: anti skid stainless steel
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E S C A L AT O R S Curved As the name suggests, these escalators are turned at an angle in one direction or two directions Details: Details : Inclination : 30 Vertical rise : 3500 - 6000
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W A K A L AT O R S • • • •
Walkalator is a slow moving conveyor mechanism that transports people across a horizontal or inclined plane over a short to medium distance. Walkalators can be used by standing or walking on them. They are often installed in pairs, one for each direction. The first moving walkway in an airport was installed in 1958 at Love Field in Dallas, Texas.
Types of Moving Walkways: 1. According to Inclination Angle: Horizontal and Inclined Walkways a. Zero degrees inclination – “Horizontal” Moving Walkways b. Upto 15 degrees inclination – “Inclined” Moving Walkways
Inclined walkway
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Horizontal walkway
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W A K A L AT O R S 2. According to the Flat Moving Surface: a. Pallet Type A continuous series of flat metal plates mesh together to form a walkway. Most have a metal surface, some models have a rubber surface for extra traction. b. Moving Belt These are generally built with mesh metal belts or rubber walking surfaces over metal rollers. Both of these types have a grooved surface to mesh with comb plates at the ends. They are built with moving handrails, similar to those on escalators.
Pallet type walkway
Moving belt walkway
3. According to the Speed: a. Slow-speed Standard type The speed of these walkways is determined by the need for safety upon entry and exit, which generally limits it to approximately half normal walking speed, or 30-40m/min. b. High-speed type On entering, there is a 10m acceleration zone where the walkway is a series of metal roller. At the exit, the same technique is used to decelerate the walkway. • Moving Walkways may run horizontally or on an incline of up to 15 degrees. • The flat moving surface of the moving walkways consist of a continuous rubber belt or a series of jointed treads.
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FA S T E S T E L E VAT O R S / L I F T S I N T H E W O R L D WORLD’S FASTEST LIFT : SHANGHAI TOWER Speed Capacity People
20.5m/s 1600 kg 21 people
-The fastest installed elevator reaches speeds of 67 feet/20.5 meters per second, or 46 miles per hour (73.8 kilometers per hour) in the Shanghai Tower. -Edgett created an elevator system in which office floors are served via 4 sky lobbies each served by double-deck shuttle elevators. -It also has the record for furthest travelling single elevator in the world at 1,898 feet. -The motor in the elevators has a built-in converter that regenerates electricity. This reduces the elevator’s power consumption by more than 30%, according to Mitsubishi. -The safety gear is made up of ceramic material that can withstand high heat and friction. -A powerful permanent magnet motor and two large-capacity control panels enabled elevators to run at a speed of 20.5m/sec -Advanced acceleration and deceleration control mitigates passengers' discomfort - heavy during ascent and weightless during descent. -The car is streamlined to minimize wind noise. Additionally, the car structure is designed to shut out shaft noise.
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FA S T E S T E L E VAT O R S / L I F T S I N T H E W O R L D WORLD’S SECOND FASTEST LIFT : GUANGZHOU CTF FINANCE CENTER Speed Capacity People
20m/s 1600 kg 21 people
-It achieves this speed by means of a thin-profile, permanent magnet synchronous motor and a compact traction machine that makes the lifting system lighter. -To regulate the speed of the elevator there’s a governor, and the braking system uses high-temperature resistant materials for emergency stops. -The air pressure is adjusted in order to prevent ear blockages and the elevators have rollers to smoothen the ride
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ASSIGNMENT 5
Questionnaire
QUESTIONNAIRE HVAC: 1.What are the 4 major steps in a chiller? 2. What are the types of MERV filters? 3. What is the formula for co-efficient of performance? 4. Define latent heat source gain? 5. What is AHU? 6. Working of a condenser? 7. Types of mechanical systems? 8. Working of an FCU and its components? 9. How does the radiant flooring in humid seasons? 10. What is a heat pump? 11. What are roof handlers? 12. What is water source heat pumps? 13. How do the ducts help in various systems? 14. What are materials used in a FCU unit? 15. What are different types of hot air systems and which one of them are commonly used? 16. How does the all-air system work? Explain with diagram. 17. Different principles of a cooling tower 18. What is through the wall unit? 19. What is the principle of a CAV system? 20. How does the VAV system work? 21. How does the ductless mini-split work? 22. What are guideline for residential cooling and heating systems? 23. How do diffusers help? 24. Does the orientation of the units matter? What are the necessary dimensions depending on? 25. What is EER and SEER? 26. How are geo-exchange heat pumps better? 27. What do the economizers do? 28. How do dampers help in HVAC systems? 29. What are the most common systems used in humid area? 30. Write the formula for efficiency of cooling tower. 30/4/2021
31. Explain the role of heating plate. 32. What is by-pass air? 33. Define apparatus dew point. 34. Mention the outside and inside unit of a chiller system 35. What do you mean by sensible heating? 36. List down 5 types of cooling systems 37. Why is district cooling system used? 38. Which are the four stages of Carnot cycle? 39. What is the COP of the Carnot refrigerator? 40. What is Cooling Load? ELEVATORS/ESCALATORS: 1. Which is the world's fastest elevator? Mention any of its features. 2. What are components of an elevator? 3. What is the minimum speed for escalators and elevators? 4. What materials used in elevators and escalators? 5. How is the depth of the shaft-ways in elevators determined? 6. What are bumpers? 7. What is a Governor? 8. Mention types of elevators. 9. What is the width of an escalator? 10. Working principle of hydraulic passenger elevators
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ANSWER KEY HVAC: 1. Evaporator, compressor, condenser, expansion valve 2. MERV 6 Filter, MERV 8 Filter, MERV 11 Filter, MERV 13 Filter. 3. Co-efficient of performance = Cooling effect / Work input 4. Indirect heat (addition of water vapour) 5. AHU or Air Handling Units are devices which condition ambient air and distribute it within a building. 6. Condenser changes the hot liquid refrigerant to cold liquid refrigerant. 7. Elevators, air conditioning, escalators, cooling systems etc. 8. A Fan Coil Unit is the unit placed over the ceiling for heating or cooling purposes. It consists of ducts, filter, fan, coils and diffuser. The fresh air duct pushes the air into the unit when the filter filters the air and the air is then pushed into the coil zone by the motor fan. The air in the coil zone is either heated or cooled accordingly. There are two coils for heating and cooling both connected to the boiler and chiller respectively. The water that is provided into the coil zones cools and condenses or heats up before finally distributing through the diffuser into the room. Once the air is used, it either goes back into the ceiling to mix with fresh sir before entering the FCU or it exits through the return ducts. 9. Depending on the particular climate and system design, airflow can be reduced by up to 80% which in turn results in less ducting required to move air around the building. The panels have rapid cooling times and thus allow for a more compartmentalized approach which is extremely effective in humid climates. The radiant system offers direct thermal control of active surfaces (panels and slabs) and indirect control of temperatures of non-active surfaces.
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10. Heat pumps are an efficient system that extracts heat from a cold space (such as the outdoors during winter), and then warms and releases it into a room so as to control the temperature inside. When used for heating, heat pumps use the same refrigeration-type cycle that is used in an air conditioner, but rather than release the air outside as a cooling system would do, it pushes air in the opposite direction (i.e. back into the room to be heated). Heat pumps can also be used for cooling a room, reversing the flow of air to again expel the heated air that is brought into the system 11. Rooftop units are also often known as air handlers, and as their name suggests, they’re a large HVAC system that is placed on a rooftop in order to moderate the temperature of a large space. Inside the big boxes that you see on top of office or apartment buildings are a blower, heating and cooling elements, filter racks, and chambers and dampers. These boxes typically connect with a ductwork ventilation system, that will then distribute the air through the building before returning it to the box to either discharge or return air back into the system (depending on the model). 12. Water source heat pumps are relatively uncommon as they require proximity to a body of water; geothermal heat pumps, however, are rapidly escalating in popularity. Regardless of whether it’s a system drawing on water or the ground, these pumps offer both heating and cooling systems that transfer heat into or out of the ground by taking advantage of the more moderate temperatures of the earth to boost the efficiency of the system. 13. Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, supply air, return air, and exhaust air. Ducts commonly also deliver ventilation air as part of the supply air. 14. Box: galvanized or stainless steel, Coil: cooper, Filter: MERV 8
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ANSWER KEY 15. Forced Air Systems. A forced air heating system is the most common option that is found in a residential home Electric Systems. Geothermal Systems Radiant Heat Systems Steam Radiant Heat Systems 16. In an all-air system, air is blown across the cold evaporator coil and then delivered by ducts to the rooms that require cooling Air systems can effectively cool, heat, ventilate, filter, and dehumidify air. The main disadvantages are the bulky duct-work and large fan power required 17. Cooling tower systems work by using water to extract waste heat from a system and ejecting it into the atmosphere primarily through evaporation. The three key components of a cooling system are the cooling tower, recirculating pump, and heat exchanger. Water first passes through a heat exchanger where it absorbs heat. 18. A wall unit is a single, self-contained air conditioner that allows you to cool any room, with or without windows. It requires no ductwork. The wall air conditioning unit is installed through an exterior wall. 19. Constant air volume (CAV) is a type of heating, ventilating, and air-conditioning (HVAC) system. In a simple CAV system, the supply air flow rate is constant, but the supply air temperature is varied to meet the thermal loads of a space. Most CAV systems are small, and serve a single thermal zone. 20. VAV system is a single-duct system that can easily have many zones. A variable-volume control box is located wherever a duct enters a separate zone (Fig. 16.14h). A thermostat in each zone controls the airflow by operating a damper in the VAV control box. Thus, if more cooling is required, more cool air is allowed to enter the zone. Since VAV systems cannot heat one zone while cooling another, they are basically cooling-only systems
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21. The smallest of all systems, the ductless or mini split air conditioner is designed for small deployments such as a single large room, or multiple small rooms. They require minimal wall space, and the compressor and heat exchanger unit can be located further away from the main building, allowing greater flexibility in use. This is the main type of air conditioner you’ll find on the market, as it’s explicitly designed for home use and fits into the consumer mass-consumption model. These systems are easy to install, even as a home project, and the internal unit is aesthetically pleasing as it forms part of the furniture. The downside to ductless systems is that they can cost more to operate than central systems 22. Use 1 ton (3.5 kW) of cooling capacity for each 500 ft2 (45 m2) of a standard house. Use 1 ton (3.5 kW) of cooling capacity for each 1000 ft2 (90 m2) of a modern, well-designed, and well-built house 23. • To deliver both conditioning and ventilating air • Evenly distribute the flow of air, in the desired directions • To enhance mixing of room air into the primary air being discharged • Often to cause the air jet(s) to attach to a ceiling or other surface, taking advantage of the Coanda effect. • To create low-velocity air movement in the occupied portion of room • Accomplish the above while producing the minimum amount of noise. 24. The orientation does not matter but the placements of the units matters. For example, the space between the FCU unit and the fresh air and return ducts is a must. 25. EER- Energy Efficiency Ratio (EER) is a measure of the cooling capacity (i.e., maximum output possible) divided by the energy input. It is often used to rate residential air conditioners. SEER-Seasonal Energy Efficiency Ratio (SEER) is a measure of the total cooling output (actual output) during the whole overheated period divided by the total energy input during that same period. It is often used to rate residential air conditioners
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ANSWER KEY 26. Geo-exchange heat pumps are also known as geothermal or ground-coupled heat pumps. “Ground-coupled” is a good descriptive term, but “geothermal” is not because it is already in use to describe high-temperature heat obtained from deep within the earth. “Geo-exchange” is an excellent term, because in the summer, heat pumps move heat from indoors to the ground, which acts as a heat sink, and in the winter, the heat is moved back from the ground and pumped indoors again—a seasonal exchange with the earth (“geo”). Water is used to transfer the heat from the heat pump to and from the upper layer of the earth (less than 100 ft. [30 m]). 27. Economizers are mechanical devices intended to reduce energy consumption. They leverage favourable ambient conditions to provide cooling without using compressors and are commonly integrated into cooling systems to minimize annual compressor use. 28. A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air-handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate con 30.(Ti-To)100/(Ti- Twb) 31. Heat plates helps in transferring of heat from one system to another 32. The air which comes out from the cooling coil is called bypass air 33. Cool air coming out of the coil or the effective surface temperature of the cooling coil 34. Inside unit- expansion valve and evaporator Outside unit- compressor and condenser 35. It is the direct heat gain (ex from windows, doors etc.)
37. District cooling system is used to distributes cold refrigerant from a central part to multiple buildings. 38. Isothermal Expansion, Adiabatic Expansion, Isothermal Compression, Adiabatic Compression are the four stages of Carnot cycle. 39. COP = 0.58 40. It is the thermal energy that must be removed from the space in order to maintain the desired comfort conditions. ELEVATORS/ESCALATORS: 1. The fastest installed elevator reaches speeds of 20.5 meters per second in the Shanghai Tower. 2. Hydraulic power unit, Piston, Suspended system. 3. 0.3 m/s 4. Rubber, Stainless Steel, Anti-Skid stainless steel. 5. The depth of the shaft-ways depend on the machinery used and the size of the elevator car. 6. An elastomeric bumper is the part of the handrail in an escalator, designed for the safety of passengers. 7. It is mechanical device used to control the speed of lift on the basis of load in the lift chamber. 8. Hydraulic Elevators, Machine-Room-Less (MRL) Elevators, Pneumatic elevators, Electrical lift, Paternoster lift. 9. The escalator width should be in the range of 40cm to 102cm. 10. A hydraulic elevator is power-driven by a piston that moves within a cylinder. The piston movement can be done by pumping hydraulic oil to the cylinder. The piston lifts the lift cab easily, and the oil can be controlled by an electrical valve.
36. Chilled cooling system, radiant cooling system, ahu, district cooling system, fan coil system
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REFERENCES https://www.wbdg.org/resources/solar-ventilation-air-preheating https://www.cielowigle.com/blog/radiant-floor-heating/ https://www.wikiwand.com/en/Solar_thermal_collector https://www.wbdg.org/resources/solar-ventilation-air-preheating http://ableairheat.com/long_island_radiant_heating_systems_service_repair.html http://coolvent.mit.edu/intro-to-natural-ventilation/basics-of-natural-ventilation/ https://www.priceindustries.com/content/uploads/assets/literature/engineering-guides/fan-blower-coils-engineering-guide.pdf https://fairconditioning.org/knowledge/sustainable-cooling-technologies/radiant-cooling/ https://www.slideshare.net/akashkumar102/escalators-73662641 https://www.dimensions.com/collection/escalators https://www.dimensions.com/search?query=LIFTS https://www.slideshare.net/MitaliGondaliya/lifts-46213003 ASHRAE. (2019) Heating, Ventilating and Air-Conditioning Applications-ASHRAE Handbook [pdf] Dougharty, F. (2012) Air Side Economizer design using psychrometric analysis [pdf]
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