UNIT 2 & 3 - FUELS AND GAS

INTRODUCTION

What is a fuel?

• A fuel is a substance that reacts chemically with another substance to produce heat.
• Any source of heat energy is called fuel.
• The term fuel is limited to those substances that burn readily in air emitting large amount of heat.
• When a fuel is burnt, it combines with oxygen in the air to form carbon dioxide and water vapor.
•  A lot of energy (heat and sometimes light) is also produced during this process.
• The heat generated is used for purpose of heating which can be used for various applications.

Various terms and definitions associated with Heat

• Heat – it is a form of energy which can be converted to other forms. It is measured in terms of calorie or BTU (British Thermal Unit = 0.252 kCal).
• Temperature – it indicates hotness or coldness . It is measured in terms of degree Celsius or degree Fahrenheit (10 C = 33.8 0 F).
• Sensible heat – Heat which causes a change in temperature in a substance is called sensible heat.
• Specific Heat Capacity - is the amount of heat energy required to raise the temperature of a substance per unit of mass.
• Latent heat - is the energy absorbed by or released from a substance during a phase change from a gas to a liquid or a solid or vice versa.
• Ignition Point - the lowest temperature at which a combustible substance in air will ignite and continue to burn.

CLASSIFICATION OF FUELS

Types of Fuel

Calorific value of a fuel

• Quantity of heat liberated when a unit mass of solid fuel, or a liquid fuel or a gaseous fuel is burnt completely, is known as the calorific value of the fuel.
• The combustion process also generates water vapour.
• Gross Calorific value (GCV) / Higher Calorific Value (HCV) –is the quantity of heat produced by combustion when the water produced by combustion is allowed to return to the liquid state.
• Net Calorific Value (NCV) / Lower Calorific Value (LCV) – is the quantity of heat produced by combustion when the water produced by combustion remains gaseous.
• Calorific value of a fuel is given in Kcl / Kg in case of solid and liquid fuels and Kcal / m3 in case of gaseous fuels.

PROPERTIES  OF IDEAL FUEL

• Low ignition point and high calorific value.
• Produces minimum amount of smoke, ash and soot i.e. least pollutants.
• Should be easy to store and convenient for transportation and should be economical.
• Should have moderate rate of combustion.
• Should have low content of non-volatile material.
• Should be readily available in plenty.
• Should produce no poisonous products on combustion.
• Should be measurable as accurately as possible.
• Should be user – friendly.
• Should not be subjected to any legal regulation.

FUELS AVAILABLE FOR THE CATERING INDUSTRY

Solid fuel 
Coal: It is used in boilers to produce steam.
Coal/ Coke / Wood: It is charcoal used in tandoor to make Indian breads, kebabs.
Liquid fuel
Kerosene: Rarely used in case of emergency to supplement main fuel.
High Speed Diesel: is used in oil fired boilers and water heaters.
Gaseous fuel
LPG: It is used in most of the cooking ovens in hotel industry.
PNG : It is used in countries where available.
Coal Gas: Coal gas is the cheapest to use if available.
Electricity
An expensive option.

COMPARISON OF DIFFERENT FUELS

ADVANTAGES OF SOLID FUEL:

• Low production cost.
• Easily available in plenty.
• Easy to transport.
• No expertise required to operate.
• Not subjected to any inspection by regulatory authority.
• Convenient to store without any risk of spontaneous explosion.
• Have moderate ignition temperature. 

Disadvantages of Solid Fuel

• Storage space required.
• Heat cannot be controlled.
• Pollutes the atmosphere.
• Poses heat hazard.
• Ignition time high.
• More labour required to operate.
• Not eco-friendly.
• Not allowed in city hotels.
• Not available instantly.

Advantages of Liquid Fuel

• Flow can be regulated.
• Production of energy is instant.
• Readily available.
• Not as dirty as solid fuel.
• Limited storage space required.
• More user friendly.
• Higher calorific value.
• Easy to transport.
• Require less air for combustion.

Disadvantages of Liquid Fuel

• Requires storage space.
• Lot of care is required during use.
• Releases pollutants on combustion. 
• Sources not liable in terms of purity.
• Bad odour.
• Subject to regulatory checks by authorities.
• May not be available instantly.
• Cost is high.

Advantages of Gaseous Fuels

• Easy to handle
• Once installed, saves a lot of labour.
• Flow can be controlled through regulators.
• Very little pollution.
• Instantly available.
• In some city hotels, only this fuel is allowed.
• High calorific value.
• Clean fuel.
• Supply of fuels is by govt. Agencies.
• Supply through a pipe network.
• No storage space required.

Disadvantages of Gaseous Fuels

• Transportation cost is very high because it is volatile.
• Regular check of equipment and supply line is required.
• Lot of care is required in operation.
• Dependence on supply agency for availability.

Advantages of Electricity

• Instant fuel when electricity is available.
• No pollution.
• No storage space required.
• Eco – friendly.
• Very easy to operate.

Disadvantages of Electricity

• It is costly.
• Cost of maintenance is high.
• Chances of short circuit and hence could lead to fire.
• Equipments need to be handled with care.

Methods of Heat Transfer

Heat transfer is important in cooking appliances as the food items receive heat from heat sources.
Cooking as an important activity in hotels.
Cooking methods make use of the following methods of heat transfer.

• Conduction
• Convection
• Radiation

Conduction

• This is the heat transfer method in which heat is transmitted from a hotter part of a body to its colder part without any actual movement of the material.
• The movement of heat is through direct  contact.
• The rate of heat transfer through the body is called thermal conductivity of the material.

Convection

• This is the heat transfer method in which heat is transmitted from the hotter part of the body to its colder part by actual movement of the material particles.
• It is possible in liquids not in solids.
• There are two types of Convection:
• Natural Convection 
• Mechanical or forced Convection

Radiation

• The process in which heat is transmitted from one place to another without the help of any material medium or without heating the intermediate medium.
• It does not require any physical contact between heat source and the food being cooked.
• Heat energy is transferred by electromagnetic waves or heat waves.
• This mode of heat transfer is very efficient and very fast.
• Used in microwave cooking.

MOST COMMON GASEOUS FUELS IN HOTELS

Two most commonly used fuels in hotels all over the world are:

• LPG (Liquid Petroleum Gas)
• PNG (Piped Natural Gas)

LPG (Liquefied Petroleum Gas)

• It is a mixture of hydrocarbons – Propane (C3H8) and Butane (C4H10) with larger percentage of propane.
• It is derived from the fractional distillation of crude oil in oil refineries.
• LPG is gaseous at normal atmospheric pressure, but may be condensed to the liquid state at normal temperature by the application of moderate pressure.
• It is stored and transported as liquid under pressure for convenience and ease of handling.
• MoPNG

Properties of LPG

• Combustion of LPG produces carbon dioxide (CO2) and water vapours and requires sufficient air, otherwise carbon monoxide (CO) is produced which is toxic.
• Its calorific value is approximately 11,000 Kcal / kg.
• It is stored as liquid under high pressure.
• The auto ignition temperature of LPG is 500oC.
• Detection of leakage of LPG is very important and cannot be ignored as the vapours of LPG evaporates to produce 250 times volume of gas. 
• Due to this reason it can be ignited at a considerable distance from the source of leakage leading to  hazards.
• Since it is a colourless and odourless gas, an odourant called ethyl mercaptan is added to LPG  for easy detection in case of a leakage.

ADVANTAGES OF LPG AS A HOTEL FUEL

• High efficiency and heating rate.
• High calorific value – approx. 11,000 Kcal/kg.
• Complete combustion and no smoke.
• Clean fuel.
• Portable.
• Cheaper than electricity.
• Quantity can be verified at the delivery point.
• No expertise required.
• From a single cylinder multiple stoves can be operated.
• The price of LPG is fixed by the Govt. of India.
• Non – toxic and eco – friendly.

SAFETY IN USE OF LPG

• Always use BIS (Bureau of Indian Standards) – approved appliances, regulators and Suraksha rubber tubes from authentic sources.
• Check that the cylinder has the company seal and safety cap intact.
• The equipment should be cleaned regularly, as the gas corrodes metal.
• Always keep the cylinder in upright position at ground level in a well ventilated place.
• The gas cylinder should not be titled to an inclined position while being used, in order to completely utilize the gas.
• Inflammable  material should not be kept very close to the gas bank.
• The flexible metal hose connecting the gas valve and oven should be checked at regular intervals, for crack or damage.
• The burner knobs and cylinder regulator must be switched off after work is done.
• Burner heads should be cleaned daily.
• Never keep kerosene or other stoves on the floor where an LPG cylinder is in use.
• Check the cylinder valve to ensure that the rubber ‘O’ ring is present inside.
• Use only soap solution to check gas leaks; never use lighted match sticks for checking leaks.
• Retain the safety cap with a thread attached to the cylinder. Fix the cap on to the valve to stop leaks, if any.
• Do not store inflammable material like rubber mats, coir etc., inside the kitchen or above the stove.

STEPS IN CASE OF LPG LEAK

• Close the regulator and burner knobs.
• Do not operate electrical switches or appliances in the room.
• Switch off the main power supply.
• Open all doors and windows for ventilation.
• Put off all flames, lamps, incense sticks etc.
• Put the safety cap on the cylinder.
• Call your distributor or emergency service cell for help. 

GAS BANK

• All hospitality units have large kitchens for daily servie of food items.
• Instead of having individual gas supply to the ovens, a gas bank is often installed in a centralized arrangement usually outside the kitchen.
• When  more than one cylinder is connected together through a common header(manifold) it is called a Gas Bank. 
• Short pipelines connect each individual oven to this common supply line.
• Depending on the number of burners or total consumption the size of the Manifold is decided. 
• Gas banks usually have a primary cylinder bank and a secondary cylinder bank.
• In  fully automatic gas bank, the installed system automatically switches to the reserve bank when the primary bank is depleted.
• A LED indicator would indicate an empty bank by turning red.
• An alarm buzzer will also sound to indicate an empty bank.
• The indicator turns green as soon as the system is reset by replacing the depleted cylinder.
• The buzzer also stops.
• The output from the Manifold is regulated through Pressure Regulator and then suitable Gas pipe line is extended in the Kitchen area.

SAFETY PRECAUTIONS WHILE SETTING UP A GAS BANK

• Non – return valves are provided for individual cylinders.
• Flame arrestor is installed to work as safety device

• Cylinders and manifolds are connected through high pressure pig tails and adaptors.
• The operating pressure of the supply gas can be set by primary and secondary regulators.
• Pressure gauges are installed to indicate the gas pressure in the cylinder and the manifold lines.
• An LED indicator and an alarm buzzer are used to indicate the depletion of the primary bank.
• Manually operated shutoff valves are installed on the left and right of the header bar.

Gas Burners

• Gas burners can be classified as Low Pressure burners (approx. 0.15 Kgf/cm2) and High Pressure Burners(approx. 4.22 Kgf/cm2).
• The burner has a mixer head (venturi) , throat and burner head.

• The mixer head carries an air shutter and a hole for the gas orifice, which is the opening through which the gas flows and by means of which the flow is controlled.
• There are openings in the form of small holes in the burner through which gas air mixture comes out and burns into gas flames.
• These openings are called ports, which are distributed horizontally in series of rows from inner to outer portion of the burner.

LPG Burner

UNIT 12 - AUDIO VISUAL EQUIPMENT'S

INTRODUCTION

Hotels have a large number and variety of audio visual equipments, detectors and sensors.
The actual variety and number of such equipments depend upon the type of business being carried out by a particular property.
Eg. A convention hotel will have less of such equipments, while a primarily lodging hotel will have less of such equipments.

TYPES OF AV EQUIPMENTS USED IN HOTELS

Although  hotels widely differ in the types and number of AV equipments, the following are mostly included in standard hotels.

qVideo  Players and Recorders	qFollow Spot Lights
qKaraoke System	qLoudspeaker
qMicrophone	qOverhead Projectors
qPortable Screens	qFixed Projector Screens
qLCD/LED	qCCTV
qDesktop/Laptop Computers	qWireless Keyboards and Mouse

CARE AND MAINTENANCE OF AV DEVICES

Audio- Visual equipments are mostly sophisticated electronic equipments, and as such they must be handled with proper care and maintained regularly to ensure their proper functioning.
Usually, the sound systems are maintained regularly to ensure their proper functioning. Usually, the sound systems are maintained by outsourcing to contract maintenance.
The video units, LCD monitors, computer systems, projectors, cameras etc. usually have some kind of warranty and service contract.
However, there must be some care in operating them and regular routine of cleaning them that greatly enhances the life and performance of the equipments.

LCD/ VIDEO PROJECTORS - Care and Maintenance

These projectors work with computers and have become extremely popular for making presentation on screen that were earlier done with overhead projectors(OHP) and slide projectors.
Projectors are very sophisticated equipments and great care is needed in operating them.
The start procedures are controlled through various control buttons on the projector and they need to be strictly followed in accordance to the instructions.
They produce a lot of heat ranging from 400 to 500 degrees. To remove this heat, cooling fans are installed within which contain filters. These filters need to be cleaned or changed through regular maintenance. If not done so, any dust particles in the projector can cause visual anomalies.

LCD/ VIDEO PROJECTORS - Care and Maintenance 

Projector lens should be cleaned with isopropyl alcohol or a photographic lens cleaning solution. Apply the cleaning solution to cloth and wipe the lens. Never apply the cleaning solution to the lens directly.
LCD projectors must be used at temperatures between 5 and 35 degrees Celsius.
Dust should be regularly blown off from the lens by means of a blower but from a safe distance.

Care and Maintenance of Computers and its peripherals

Computers and their peripherals are quite robust and reliable.
However, casual use of different components, may lead to serious problems ranging from faulty and unreliable operations to complete stoppage of operation.
A few routine care and maintenance schedule can ensure trouble free operation for a reasonable period of time.
But in case of serious problems, professional help should also be taken.

Care and Cleaning of LCD screens

Utmost care must be taken while dealing with LCD screens.
THE DO’S

• To remove stains on the screen, properly clean the display surface by gently wiping it with a lint free cloth and glass cleaning agent.
• Avoid strong shocks and vibrations.
• Be sure to use and store LCD monitors within the specified temperature and humidity range.
• The screen should be turned off or brightness should be reduced to prevent ‘burn-in’, which is a permanent damage to certain pixels in the LCD due to overheating.

THE DONT’S

• Do not place any heavy object on the laptop.
• Do not scratch, twist or hit the surface of the LCD screen.
• Do not spray cleaning  liquid directly on to the screen.
• Do not let moisture accumulate .
• Never disassemble the LCD monitor, as the internal backlight assembly can retain a charge of 1000 V and may prove fatal.
• LCD screens should not be subjected to sudden temperature change.

Care and Maintenance of Printers

The most common problems faced while using a printer are: poor print quality, streaking print, white lines through prints, no print etc.
Most of these problems originate from ink drying up at the print head or nozzle and clogging them during printing operation.

• Running the printer at least once a week helps avoid these problem.
• Use the printer at least on a weekly basis with both black and white and colour text printing.
• Always use printer switch rather than the UPS or Power switch to shut down the unit.
• Refilling for colour cartridge must be done with proper ink in the proper chamber.
• It is always better to refill an inkjet cartridge before it is empty as the ink of dried up cartridges, if left for too long will clog the print head.
• Laser printers should be kept in a dust free area.

UPS – Maintenance and Care

A UPS (Uninterruptible Power Supply) provides instant emergency power to connected equipments by supplying power from a separate source (battery) in case of a failure of the main power supply.
The battery is the most important part of the UPS. A periodic maintenance program extends the life of the battery.
The following steps can help establish a good maintenance program for he UPS battery.
UPS – Maintenance and Care (contd..)
Inspection: Periodic inspection should be carried out .
Periodic measurements: of the voltage, temperature, resistance etc. should be measured to ensure that the battery is operating to its optimum.
Load testing: When the battery can no longer supply 80 % of its rated current, the aging process begins and the battery is considered for replacement. Individual cells of the battery should be monitored, so that only the weak or bad cells can be identified and scheduled for replacement.
Record Keeping: All data collected through the above maintenance program should be documented to track the performance of the battery over time.

A Few Good Maintenance Practices for Reliable Operation of Computer Systems

Computer systems are now a part and parcel of modern organizations.
Smooth and efficient functioning of the organization nowadays depend a lot on continuous and reliable functioning of the systems.

•  Switch off computers only after the operating system has properly shut down the computer.
• Always use a UPS.
• Keep the operating system software and other important utility software in a secured place.
• Run scandisk and defragment the file system once a month.
• Take regular data backup.
• Keep at least 250 MB of C: drive free.
•  Do not let many programs load up in the computer memory or RAM when the computer starts.
• Avoid storing files on the desktop.
• Run system file checker twice a month.
• Remove all unnecessary files and folders from ‘My Documents’ directory and empty ‘Recycle Bin’ once a month.
• Get all critical windows update.
• Scan the computer with antivirus at least once a week.
• Install firewall protection for Internet access
• Clean computer and its accessories on regular basis.

Sensors and Detectors

The hotel industry, because of its very special nature of business, requires a host of sensors and detectors for reliable, efficient and safe functioning. A number of them are listed below:

Different Types of Detectors

Smoke Detectors	Heat Detectors
Occupancy Detectors	CCTV
Gas leak Detectors	Photo sensors
Flame Detectors	pH detectors
Gas detectors	Flame Monitoring System
Carbon monoxide level detector

Smoke Detector - A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial security devices issue a signal to a fire alarm control panel as part of a fire alarm system.
Heat Detector – A heat detector is a device that detects sudden change in temperature in the place where it is installed. If the rise in temperature is above a predetermined level it issues a signal to the water sprinkler system.
Occupancy detector – Occupancy or motion detectors are devices that turn lights and other equipments on or off in response to the presence or absence of people in a specific area in the field view on the sensor.
pH Detector – They are used to monitor the pH value of water in  certain areas of the hotel like, Water Treatment Plant, Boiler, Swimming Pool, Sewage Treatment Plant.
Gas Leak Detectors  - They are used to detect LPG  leaks from Gas banks.
Gas Detectors – They are used to detect the presence of various gases within an area that might be harmful. They are used to detect combustible, toxic and CO2 gases.
Flame Detector – A flame detector uses optical sensors to detect flames.
Carbon Monoxide Level Detector – It detects the presence of carbon monoxide and sets in some kind of alarm so that the situation can be controlled by measures such as improved ventilation of the area and/or evacuation of occupants from the affected area.
Photo Sensors - These sensors are used to detect the amount of daylight available and accordingly vary the light output  of illumination bulb and tubes and also switches on and off the lights in the premises in a property. It helps in energy conservation and reducing the power consumption bill of the property.
Close-circuit TV or CCTV
CCTV is an arrangement that uses electronic eyes of video cameras to transmit a signal related to human activities in some specific place to some storage space or to a limited set of cameras.
They are the most commonly used type of surveillance equipments.

Objectives of Installing CCTV in Hotels

• To protect customers
• To protect assets from pilferage and theft, such as in a liquor storage room.
• To prevent loss by way of legal compensation by identifying false claims by customers.
• To help get insurance claims in case of property damage due to fire etc.
• To gain control over activities of employees.
• To monitor various activities in the hotel.
• To identify offenders.

UNIT 10 - HOTEL SECURITY

Security

Security as a condition is the degree of resistance to, or protection from, harm.
 It applies to any vulnerable and valuable asset, such as a person, dwelling, community, nation, or organization.
Establishing or maintaining a sufficient degree of security is the aim of the work, structures, and processes called "security."

Concept in Hotel

It is the moral and legal responsibility of a hotel to protect its guests and their property against threats posed by human beings with a conscious intent to harm them.
The security department of the hotel is responsible for the overall security of the building, in-house guests, visitors, day users, and employees of the hotel.

Security? Why?

Hotel guests want to feel safe and secure in their temporary home. Hotels have a duty to protect them. After all, the business depends upon them.
 Apart from the possibility of death or injury and destruction, the adverse publicity from an incident, can result in ruined reputations, failing business and knock-on effects to tourism in the country or region.
Hotel staff may not even become aware of risks that some guests may bring with them. Consequently a hotel must be vigilant at all times.

What are the risks?

Examples of Risk

•  Terrorism 
•  Kidnapping 
•  Robbery by organized crime 
•  Opportunist robbery 
•  Burglary from rooms  
•  Baggage theft 
•  Invasion of guest privacy, by locals, press, interest groups 
•  Blackmail of staff

Poor Hotel Security

The use of technology, has greatly impacted how criminals can target hotels. 

For instance, instead of visiting a hotel to collect many pieces of information, a criminal can now scan the Internet pulling up specifics about room numbers, location to other areas of interest, the leadership team and photos of critical areas in the property.
 Using applications like Google Earth, a criminal can diagram the structure and their escape routes.

Consequences

• Possibility of death 
• Injury
• Destruction
• The adverse publicity from an incident
• Result in ruined reputations
• Failing business and knock-on 
• Effects to tourism in the country or region. 
• The risk to hotels can also increase because of the identity  of an individual guest or his or her family. 
• VIP’s,  celebrities or the infamous can present special difficulties.
• Easy terrorist attacks

Effective Hotel Security

Now since we know what could be the consequences, it is always better to prevent it than curing it.
Sometimes some things may be irreplaceable and it is always preferable to avoid such circumstances.
In order to avoid such circumstances, an effective hotel security program is formulated in the hotel organization.

Effective Hotel Security Programs

An effective hotel security programs enables the hotel to avoid preventable incidents and react to a quick, appropriate manner.
Three basic elements should be included in the program.

1. People
2. Procedure
3. Equipments

People
No matter which department or post everyone can contribute in making the hotel a safe place for all.
This is not only the concern of the security department.
Procedure
Every property needs to have procedures for the staff to follow. The staffs should be well informed about the emergency procedures as well as any unusual events.
Equipments
Simple safety equipments to state-of-the-art security surveillance system all help make today's hotels a safer and better place to be.

Types of Security Providers

Depending upon the various factors such as the company profile, structure, capacity, location, safety requirements as well as feasibility and economy of the hotel, a hotel chooses one of the following types of security service providers:

1. Proprietary/ In- House Security
2. Contract Security

Proprietary security and contract security companies are responsible for protecting companies and businesses and ensuring the safety of employees and consumers.
A proprietary security company is controlled entirely by a particular company(hotel itself in this case) and is responsible for the hiring, firing and management of personnel.

 A contract security company is operated by a professional security company and contracts its services to different companies.
Cost
Proprietary security is more expensive because your company is in charge of paying for benefits and higher wages for experienced personnel.
Because the status of proprietary security is considered higher, it usually attracts a higher quality of guard.
The wages tend to be lower with a contract security company because uniforms, sick leave and training benefits are all covered by the service.

Control
Proprietary security employees often feel more loyal to a particular company, because they feel a camaraderie with fellow employees and have an opportunity for growth and promotions.
There may be periods of time when a company may have to add or lay off workers, which can create a security problem within a company.
 By using a contract security service, companies have the opportunity to deal with staffing problems easily and quickly.

Categories of Security Equipments

They can be broadly divided into 5 categories:

1. Equipment for Physical Security and perimeter control.
2. Equipment for Surveillance
3. Communication System
4. Alarm System
5. Equipments for Guest Room Security

Physical Security and Perimeter Control

Physical security involves the protection of the hotel buildings, its ground and the assets within the building.
Perimeter control is concerned with restricting access to a property.
What are the equipments used in physical security and perimeter control?

• Access control systems allow authorized personnel and material to move through normal access routes while detecting and delaying movement of unauthorized personnel and material.
• Access control adds little, if any, enhancement to a structure’s physical barriers. The use of electrically operated locks and strikes with access control systems may actually reduce penetration delay times for doors.
• Thus, access control systems must be integrated with other components of the overall physical security system to be effective. This will ensure that personnel seeking entry to the protected area are queued at the control point(s).
• There are many different types of access control systems and they vary extensively in their complexity and capabilities.

Equipments for Physical Security and Perimeter Control

• Computer security equipment
• Locks
• Safes
• Safety deposit centers
• Security doors
• Security fencing
• X-ray machines, free standing metal detectors, hand held metal detector
• Shutters and grilles
• Explosive detectors
• Steel office storage and furniture
• Vacant property protection: concrete, temporary fencing, barb wire

Equipments for Surveillance

Surveillance is the monitoring of the behavior, activities, or other changing information, usually of people for the purpose of influencing, managing, directing, or protecting.
The word surveillance is the French word for "watching over"; "sur" means "from above" and "veiller" means "to watch“
In simple terms it can be defined as the “careful watching of someone or something.

Equipments of Surveillance

Apart from other sophisticated surveillance equipments such as Biometric Reader- retina recognition, voice recognition, finger print recognition or the surveillance from the satellite, hotel surveillance is done either personally or by the help of Closed Circuit Television Cameras which not only helps us to see what is going on but also record it at the same time on your PC, Laptops or smart phones as well.

HOW HOTEL VIDEO SURVEILLANCE CAN BE BENEFICIAL

1. Security – Hotel video surveillance can help keep your guests safe from theft and other criminals by helping you track your visitors and prevent break-ins on your property.
2. Prevent theft – Hotel security cameras can help keep intruders out of exclusive hotel areas like swimming pools and gyms, where theft is common. A surveillance system in your store room and other maintenance areas can uncover potential employee theft.
3. Remain competitive – Along with providing security, a professional video surveillance system gives your guests peace of mind while staying at your hotel, and can help you increase your return business and remain competitive in an aggressive market.
4. Flexible – Modern security cameras are easy to install and can be adjusted at anytime to fit your needs. Unlike analog CCTV cameras, wireless IP cameras don't require technicians, power tools, or miles of wiring. All you do is mount the cameras and start recording.
5. Remote monitoring – Adding an NVR (Network Video Recorder) to your security camera system gives you the ability to broadcast your surveillance footage over the internet. This breakthrough in surveillance technology allows you to monitor any of your cameras at any time from any internet connection, giving you instant security updates

Alarm System

A burglar alarm is a system designed to detect intrusion – unauthorized entry – into a building or area. They are also called security alarms, security systems, alarm systems, intrusion detection systems, perimeter detection systems, and similar terms.
Burglar alarms are used in residential, commercial, industrial, and military properties for protection against burglary (theft) or property damage, as well as personal protection against intruders. Car alarms likewise protect vehicles and their contents. Prisons also use security systems for control of inmates.

Types of Sensors on alarm

In hotel alarm systems are often used for monitor the many entrances and emergency exits found throughout a hotel.
There are various type of sensors used in the alarm according to its different functions – fire, burglary, heat, smoke etc.

Equipments for Guest Room Security

When we travel to different places, the main reason that we choose a good hotel is the assurance of a safe, clean and comfortable room.
Different security equipments installed in the room makes the guest feel safe and comfortable even when they are travelling away from their own safe dwellings.
 Hotel guest room security may be enhanced by the use of security equipment such as hotel/motel function locks, safety chains, and similar devices.
Secondary access limiting devices on sliding glass, balcony, and connecting room doors, access limiting devices for operational windows, a guestroom telephone or other communication device available for use 24 hours a day, a peephole in or window next to the guestroom door etc.

Biometrics

A new and highly technical access control system involves biometrics. Such a system utilizes human characteristics which are unique to a specific individual. No two Fingerprints are same anywhere in the world , the retina or iris of an eye, and the size, shape, and even the  print of a hand.
In Future biometric applications  there would be the possibility to include a person's voice being recorded at check-in and immediately being transmitted to the door accessing a restricted guestroom corridor, guestroom, health club, point-of-sales locations throughout the premises which is only limited to guest access.

View ports

Consider the need for the guest to be able to identify a caller before opening the door. A view port [door viewer or peephole] is one device that can serve this purpose.
A wide-angle view port maximizes the view of the corridor adjacent to the guestroom door.

Other Necessary Equipments

Smoke Detectors
Smoke or heat detection units are required by an increasing number of local jurisdictions. Regulations vary from those only requiring smoke and/or heat detectors in corridors, storerooms, and under stairways to those requiring full systems that provide protection in every guestroom, guest bathroom, public area, and back-of-the-house location.

Carbon Monoxide Detectors:-
Carbon monoxide is a dangerous by-product of a malfunctioning water heater, kerosene heater, coal boiler, or any other wood, coal, or petroleum product unit. (It is also the most critical toxic gas generated in any structural fire).
There have been tragic incidents in which carbon monoxide from such units has resulted in the death of a guest or staff. Since carbon monoxide is invisible and has no smell, it cannot be detected by natural means.

Accident Prevention Signs:-
OSHA(Occupational Safety and Health Administration) classifies accident prevention signs into three categories:
1) Danger signs.
2) Caution signs and,
3) Safety instruction signs.
Danger signs: which indicate immediate danger, should be posted to warn of specific dangers and to warn that special precautions may be necessary.
 Red should be the basic color for identification of all danger signs, which include restricted area, in case of fire, do not enter, and emergency exit signs.

Accident Prevention Signs:-
Caution signs: should only be used to warn against potential hazards or to caution against unsafe practices.
The color yellow has been used to advantage for marking physical hazards on stairs in both back-of-the-house stairways and fire stairwells.
 Areas of construction or remodeling should have caution signs. Floor stand signs could warn guests of wet floors and to watch their step.
Safety instruction signs: should be used only where there is a need for general instructions relative to safety measures.
These signs are typically green with white lettering. Signs with green arrows, for example, could be used to note the path to follow between buildings or on trails.

Security Procedures

A hotel may be subject to numerous amount of threats. Some are foreseeable and some are not. It is always wise to be prepared and have a set of procedures laid down so that at the time of emergency, with appropriate in advance training, such procedures may not only help but reduce the risk level and casualties at emergency situations.
Nowadays, almost every hotel has a set of security procedures laid down for such emergency situations. Some of them are discussed in this chapter.

Surveillance and Access control

It is important that hotel security should know who are in the building and the purpose of their visit.
If the public is invited to patronize certain areas, such as bars, restaurant, banquet room, etc, it does not mean that other areas which are designated for guests, are also available to the public.
Anybody disguised as guest can get into the hotel property and remember always to keep on eye on suspected behaviour.

Precautions

There are certain precautions that are needed to be considered in monitoring access through non- public areas:

• Supervision of entrances E.g employee entrance, delivery entrances and service entrances.
• The hotel will have many different entrances which have to be taken special care of.
• Back-gate entrance of employee should be practiced.
• Delivery entrance scanning, proper checking and proper time allocation should be kept in mind while receiving deliveries like food material, maintenance parts, guest room supplies.

Routine Patrolling of guest corridor.

Security personnel, guards or even elevator operators should have an eye on the corridors as these are accessible to only guest and any suspicious person with bags, or harmful arms, or equipments should be immediately informed or taken required action.
Apart from CCTV surveillance, patrolling from time to time will help increase the security perimeters as well as stop crime on time.

Conclusion

Safety and Security is, thus seen to be a critical issue for the guest comfort and secured stay.
Guest must be able to have a secured stay and the employees should have a tension free working environment.

UNIT 9 - HOTEL SAFETY

SAFETY

ACCIDENTS

• Accidents:  can occur anywhere and at any time and in a hotel, the likelihood of accidents occurring is even higher because of the amount of human traffic that moves through it. These accidents may involve guest or staff. 
•  All accidents have to be dealt quickly without panic and keeping the interests of the hotel management in mind. 
•  The housekeeping department is normally responsible for dealing with First Aid and must maintain a first-aid box for dealing with such incidents. 
• It also makes sense to maintain first-aid facilities or box in areas more prone to accidents such as the kitchens and the maintenance departments. 
•  The services of a (house) doctor should be available whenever required. 

COMMON CAUSES OF ACCIDENTS

• Falls -  these may be due to: 
•  Objects and equipment left in the corridors, etc.-- so, remove potential hazards out of the way. Store idle equipment properly in a safe, designated place. 
•  Spillage on the floors: wipe up all spills at once. 
• Poor floor maintenance procedures: cordon off or segregate the area where floor maintenance is being carried out –such as lobby cleaning in the night shift- and use warning signs. Also, highly polished floors cause slipping.
•  Climbing on unsafe ladders: Ensure that the ladder is in good condition and placed safely and securely against the wall. 
• Loose carpet threads, banisters, etc. : repair these as they occur.  
• Unsafe surfaces: avoid climbing on furniture and ledges.
•  Over-reaching: Use safety precautions and equipment when reaching high access areas or out-of- reach spots.
•  Back Strain: This may be due to incorrect carrying of heavy loads; pushing of heavy loads; overloading of trolleys; etc. Check and maintain trolley equipment, never overload it. Train staff in correct methods of lifting and carrying of heavy articles. 
•  Cuts and bumps: These occur due to opening of doors, overloading of trolleys, careless handling of sharp material- knives, scissors, broken glass, etc. Dangerous equipment should be stored carefully and used carefully. Wear gloves when handling dangerous waste.
•  Burns, scalds, inhalation of gases and fumes: occur when hot liquids are handled without adequate precautions. When using chemicals, work in an open ventilated area, wear protective gloves, etc. Do not mix chemicals and label and store them safely. 
• Falling objects: Equipment falling from a height such as ladders and staircases can be very dangerous. So, all equipments used at higher levels should be secured carefully. On staircases keep all equipment near the wall, away from the banister area. Warning signs must be placed on the floor below an area being repaired or cleaned, etc. 
• Electric shocks: This is due to use of faulty equipment and unsafe practices when handling any equipment. Turn off the appliances before disconnecting. Do not pull on wires. Use correct fuses and never overload equipment or electrical outlets. Immediately report and repair faulty equipment and follow a regular maintenance schedule. 

PRECAUTIONS TO AVOID ACCIDENTS

• Kitchen floor areas should always be grease free- avoids slipping and fires. 
•  All staircases, especially fire exit areas, should be free from storage articles- ladders, stools, etc. 
• All corridors, corners should be well-lit. 
• In all depts. every item should have a designated storage place. Things left around cause accidents. 
• Light switches should be located at the entrances for easy accessibility. 
•  Staff should be instructed and checked to always follow all procedures and safety precautions. 
• Staff should also be trained periodically in first-aid procedures and only trained first-aiders should handle an injured person. 

GUEST ACCIDENT PREVENTION

•  Guest safety is of great importance for the hotel management and efforts must be made to keep these to a minimum. 
• Safety in the bathrooms and & guestrooms: these are more prone to accidents because of the presence of slippery, wet surfaces.
•  Keep bathtubs very clean- do not allow build-up of scum (soap) deposits
• Place rubber or anti-slip mats in the bathtub
• Provide grab bars in tubs and shower cubicles
• Keep tiles dry
• Hair dryers should be wall mounted to prevent falling into water in the sinks
• Clear broken glass as quickly as possible
•  Windows should be kept locked to avoid falls
• Wipe up all spillages on the floor as quickly as possible
• Place warning signage wherever housekeeping may be working, especially on floor maintenance

PROCEDURE IN CASE OF AN ACCIDENT

•  If possible remove the accident victim from the site of accident as soon as possible to a quiet secluded place. Make him comfortable, use a stretcher in case it is needed. 
• Preferably, take someone with you to the accident site and to help in handling the person. 
• Call the hotel doctor if the need is felt. 
• Handling of the accident victim should preferably be done by a trained first aider till the arrival of a doctor. Never try to move an accident victim who seems to have suffered a fracture- seeing an unnatural angle of the limbs, or if guest is in too much of pain, etc. 
• Keep calm, but don’t take too much time to decide on any action, time lost may be important. 
• Try to protect your establishment against any false allegations later. 
• Making a full report when the event is recent and fresh helps here. This record needs to be maintained by management in case of any queries later on or if the guest blames the hotel later on. 

ACCIDENT REPORT FORM OR ACCIDENT BOOK 

• Also referred to as the Incident Form should be available at the front desk and should contain the following information: 
•  Date and time of accident/incident 
•  Who reported the accident 
•  Room number of guest 
•  Site of accident 
•  Action taken (first-aid and doctor’s treatment and if person was removed to hospital 
• Names and statements of witnesses 
• Your own comments as to the reason of accident and how it could be prevented and what actions can be taken for future prevention of the same. 

SAFETY & SECURITY WITH RESPECT TO HOTELS IN GENERAL

• Every floor should have at least two exits. 
• The emergency staircase should connect at least 3-4 outlets in a hotel. 
• Directional sign boards (visible) should be placed at each entry and exit point. 
• Every guestroom should have a visible emergency exit map or plan behind the door and this should never be concealed with any kind of decoration. 
• Fire extinguishers should be placed at all convenient points. 
• Water sprinklers and smoke detectors or a well planned fire plan should be a part of every hotel design. 
• Metal detectors or baggage scanners can be placed at the main entrance to prevent entry of unauthorized material. 
• Each and every room door should have a ‘peephole’/ eye hole for the occupant in a convenient location. 
• Every exit area should open into an open area. 

SAFETY & SECURITY WITH RESPECT TO HOTELS IN GENERAL 

• Concierge and reception should be located at strategic points- a location from where the receptionist is able to view the movement from the main entrance. For this reason reception is located between the main entrance and the guest elevators. 
•  The hotel’s parking lot should preferably be adjacent to the main building rather than in the basement. If this is unavoidable, the hotel parking lot should require the guest to cross the lobby and the reception area in order to reach the car park. CCTV surveillance is recommended for the car park area especially if in the basement. 
• Valet service should be suggested to single lady guests .
• At the main entry of the hotel a rear view mirror may be placed in order to keep a check on the vehicles moving in and out of the hotel premises. Also, boom barriers may be installed to prevent unauthorized entry and exit of vehicles. 
• After the attack of 26/11, many hotels have started scanning and searching the underneath of cars and the car bonnets and car boot (luggage box at the rear). 
• Many hotels follow the policy of not sending their lady service staff- housekeeping and room service – to service rooms if the guest is inside the room. 
• A house maid should make sure to place the maids trolley at the entrance of the room to avoid any unauthorized or unsuspected entry of anyone while busy in cleaning. 
• CCTVs should be installed wherever necessary, especially at vulnerable points of the hotel. 

UNIT 7 - FIRE PREVENTION AND FIRE FIGHTING SYSTEM

What is Fire?

The rapid oxidation of a fuel evolving heat, particulates, gases and radiation.

FIRE TRIANGLE

There are four elements that must be present for a fire to exist.
There must be oxygen to sustain combustion, heat to raise the material to its ignition temperature, fuel to support the combustion and a chemical reaction between the other three elements.
Remove any one of the four elements to extinguish the fire.
The concept of Fire Protection is based upon keeping these four elements separate.

Sources of Ignition

Smoking
Electrical equipment
Heaters
Process machinery
Contractors tools and equipment
Arson

Fuels

Paper and boxes etc
Packaging (polystyrene beads etc)
Plastics
Solvents
Soft furnishings (Mattresses, cushions)
Furniture
Waste materials (rubbish, old pallets)

Classes of Fire

Class A – Fire in ordinary combustible materials such as wood, paper, clothing, plastics, trash etc. Here quenching and cooling effects of water or of solutions containing large percentage of water are of prime importance.

Class B – Fire in flammable liquids, like petrol, gasoline, paints etc. This category also includes liquids, such as propane and butane, but does not include fires involving cooking oil and grease.

Class C – Fires in flammable gases, methane, hydrogen, LPG etc.

Class D – Fires in combustible metals such as potassium, sodium, magnesium etc. Special extinguishing agents and techniques are needed for fires of this type.

Class E – Fires involving electrical equipment's – fires in or near live electrical equipments .

Class F – Fires involving cooking oils and fats. High efficiency deep fat fryers have necessitated the introduction of this class of fire separately. Class F fires differ from conventional liquid fires due to high temperatures involved. Carbon di oxide and multi purpose powder extinguishers are effective in extinguishing such fires.

Do Not Fight a Fire if

• It is bigger than a waste paper bin
• One extinguisher is not enough
• Smoke is affecting your breathing
• You cannot see the way out
• Gas cylinders or chemicals are involved
• Your efforts are not reducing the size of the fire
• There is any risk to yourself

Basic Fire Prevention

• Be mindful of Fire Safety
• Don’t block fire exits, call points or  extinguishers, know your exits
• No smoking policy
• Take care with any hot process, follow manufacturers instructions
• Maintain any machinery
• Observe good security
• Don’t wedge Fire Doors 
• On Hearing the Alarm
• This may include providing assistance to other persons and
• evacuating area by area 

Extinguishing Fire

• To extinguish a fire, one or more of the following steps should be taken.
• Removing / limiting the supply of oxygen by-
• Preventing air from entering the fire zone
• Putting foam to prevent entry of fresh air.
• Diluting air with a non-oxidizing gas such as carbon dioxide, nitrogen, etc.
• Stopping the supply of fuel.
• Removing heat.
• Interrupting the chemical chain reaction of the fire by using dry chemical agents.

Types of Extinguisher-Water

• Red body
• Suitable for use on Class A Fires, wood and paper etc
• Not suitable for combustible liquids, cooking fats etc
• Not safe to use on fires involving electricity
• Extinguishes by cooling

Types of Extinguisher-Foam

• Red Body with Cream label 
• Suitable for Class A and B Fires (paper, wood and non-cooking fat flammable liquids)
• Not suitable for use on fires involving electricity
• Extinguishes by cooling and sealing the surface of a burning liquid

Types of Extinguisher-Powder

• Red body with blue label
• Best on Class B (non-cooking fat flammable liquids) fires but safe to use on any type of fire
• Works by chemically interfering with the combustion reaction.

Types of Extinguisher-Carbon Dioxide

• Red body with black label
• Best on Class B (non-cooking fat flammable liquids) and Class C (flammable gases) fires but safe to use on any type of fire including those involving electricity
• Extinguishes by reducing oxygen levels and cooling
• Beware handle can become very cold (avoid touching in use)

Types of Extinguisher-Wet Chemical

• Red body with Yellow Label
• Suitable for class F cooking oil  fires
• Not suitable for class B fires
• Sprays foam as a fine mist to    form a layer over the oil
• Extinguishes by cooling and converting the oil into a soap
• Misting action prevents splashing of the oil
• Requires specialist training to use

Types of Extinguisher-Fire Blanket

Any colour body or label but they are usually red or white
For use on any type of fire but best on small contained class B (flammable liquids, may include small cooking pans) fires and people on fire
Can be used on microwaves
Extinguishes by asphyxiating

How to Use an Extinguisher

Pull the pin this will allow you to discharge the extinguisher
Get the hose or nozzle ready for
use
Aim at the base of the fire to
hit the fuel…if you aim at the
flames the extinguishing agent
will pass through and do no
good

Squeeze the top handle, this
depresses a button that releases
the pressurised extinguishing
agent

Care and Maintenance of Fire Control Equipments

Lack of maintenance can lead to extinguishers not discharging when required, or rupturing when pressurised.
They should also be available and fully functional in case of emergency.
Proper testing and maintenance schedule must be followed to have all these effective at all time.
Comprehensive Maintenance programme includes 1. Inspection 2. Testing 3. Maintenance.

INSPECTION:
A visual inspection of a water based fire system is carried out to verify that it appears to be in operating condition and is free of physical damage.
The frequency of inspection varies based on specific needs.
TESTING:
It is a procedure to determine the status of as system by conducting physical checks on water based fire protection systems such as water flow test, fire pump tests, alarm test etc.
Care and Maintenance of Fire Control Equipments
MAINTENANCE:
It is the work performed to keep equipment in operable condition by making repairs or replacing, if required. Fire extinguishers should be maintained at regular intervals, at least once a year.

Fire control equipments

Fire extinguisher

• Is an active fire protection device used to extinguish or control small fires, often in emergency situation

Hydrant and fire hose reel

• A Fire Hydrant System in an effective and efficient means of extinguishing large fires, which can otherwise cause devastation.
• Hydrant System enables the fire fighter to attack the seat of the fire from a distance.

Smoke detector and heat detector

• Is a device that senses smoke, and heat typically as an indicator of fire.
• Be signal to a fire alarm control panel

Fire alarm

• Is a set of equipment working together to detect and alert people through visual and audio appliances when smoke or fire is present
• Active from smoke , heat detector, water flow sensors which are automatic or from manual fire alarm pull station

Water sprinkler

• Is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected

Fire blanket

• Fire blankets can be used to extinguish small fires in the home, caravan, boat or garage.
• Also be used to wrap around a person whose clothes have caught alight.

STEPS TO MAKE HOTEL FIRE SAFE

1. To install appropriate fire fighting system in hotel.
2. To provide fire extinguishers in kitchens.
3. To provide sprinkler systems in required areas.
4. To provide smoke detectors and fire signals.
5. To have flame proof motors in pumps and other such motor operated equipment located in the basement adjacent to control room.
6. To provide very good electric system.
7. Regular maintenance of water boilers, geysers, AC plants etc.
8. Staff should be trained to handle fire hazards.
9. Ensure that the valves of the gas bank are shut off after the kitchen closes.
10. Regular scheduled maintenance of all fire fighting equipments.

LEGAL REQUIREMENTS

• Every hotel has to obtain fire safety certificate from local  fire services authorities.
• The restaurants and hotels with seating capacity of 50 or more persons are required to ensure fire safety measures in place irrespective of the height of the building.
• The restaurants are required to have a minimum fire safety device as specified by the local fire services department as follows:
• An underground water tank of 50,000 liters capacity.
• A terrace water tank of 5000 liters capacity for hose reel and 10,000 liters capacity if sprinklers are not provided.
• If the covered area is more than 1500 sq. m or seating capacity is more than 1000 persons there should be a sprinkler system.
• The fire water pump and fire water line have to be painted red.
• The telephone numbers of the nearby Fire Stations are to be displayed in the reception area.

UNIT 6 - REFRIGERATION AND AIR CONDITIONING SYSTEM

REFRIGERATION

Need for refrigeration

• In hotels and households, food items, both cooked and uncooked, can be preserved for a long time in low temperatures.
• Storage of fruits and vegetables makes it possible to add fresh salads to the menu all year round.
• Storage of fish, meat and other perishables items safely for longer periods is possible due to refrigeration.
• Seasonal food items can be bought from the market in bulk quantity at relatively cheaper price, stored in refrigerated conditions and later used during off season.
• Cooling of desserts and drinks.

What is refrigeration? And useful definitions

Refrigeration is the science of producing and maintaining a temperature condition in a closed space lower than the surrounding ambiance by removing heat from the space and transferring that heat to another space or substance.

TERMS USED IN REFRIGERATION:

• REFRIGERANT – It is the substance used for heat transfer in a refrigeration system. It takes up heat from inside the refrigerator cabinet and releases it to outside atmosphere.
• SENSIBLE HEAT – The heat which is used to raise or lower the temperature of a substance.
• LATENT HEAT – Latent heat is the energy absorbed or released when a substance changes its physical state. Latent heat is absorbed upon evaporation, and released upon condensation to liquid (as in clouds). 
• EVAPORATION – It  is the process of a substance in a liquid state changing to a gaseous state due to an increase in temperature and/or pressure. 
• CONDENSATION - It is the change of the physical state of matter from gas phase into liquid phase, and is the reverse of evaporation. 
• ONE TON OF REFRIGERATION – It means cooling by extracting heat at the rate of 50Kcal/minute or 3000 Kcal/hr.

Types of refrigerants and usage

Desirable properties of refrigerants

• It should be non poisonous and non irritant.
• It should be non flammable.
• It should be chemically stable.
• It should be non corrosive and should not react with the parts / components of the system.
• It should have no objectionable odour or smell.
• It should be easily and reliably detectable in case of leakage.
• Its LH of vapourisation should be high so that quantity of high refrigerant can be minimized.
• Its cost should be low.
• It should be easily available.

REFRIGERATION PROCESS

The main components of a refrigeration process are:

1. Evaporator
2. Compressor
3. Condenser
4. Expansion Valve

EVAPORATOR: In the evaporator the Refrigerant absorbs the heat from the object to be cooled and itself gets heated up. The heat absorbed is the latent heat of vapourisation of the liquid refrigerant and therefore the  refrigerant under goes a change of state i.e. from liquid to vapours without any change in temperature. The vapour refrigerant then returns to the compressor.

COMPRESSOR: The vapour refrigerant is compressed at a very high pressure and temperature. It than passes through the condenser coil.

CONDENSER: While passing through the condenser the refrigerant rejects heat either to air or to surrounding water which gets heated up. The refrigerant condenses to cold liquid state but at high pressure. This high pressure colder refrigerant then passes through the expansion valve.

EXPANSION VALVE: The expansion valve cools down the refrigerant to a low temperature and also reduces the pressure.
     It can be adjusted to control the temperature and pressure to which the refrigerant goes to the evaporator.
     The cool refrigerant is now ready to absorb heat from the hot objects while passes through the evaporator.
* Efficiency of Refrigeration System is expressed as Coefficient of Performance (COP) and is defined as the ratio of refrigeration effect produced to the mechanical work done.


REFRIGERATION CYCLE

To avoid continuous running 

of electric motor (motor required to run the compressor) and unnecessary work of compression, thermostatic control is used which senses the set interior temperature and stops the motor from running and when the temperature rises again, the motor restarts and the Compressor starts working 

again.

Compressor is the most expensive part of the refrigeration cycle and its repair is difficult. An inefficient or defective compressor is generally replaced with a new one.

Vapour compression refrigeration system

Part 1: Compression:    In this stage, the refrigerant enters the compressor as a gas under low pressure and having a low temperature.  Then, the refrigerant is compressed, so the fluid leaves the compressor under high pressure and with a high temperature.

Part 2: Condensation:    The high pressure, high temperature gas releases heat energy and condenses inside the "condenser" portion of the system.  The condenser is in contact with the hot reservoir of the refrigeration system.  (The gas releases heat into the hot reservoir because of the external work added to the gas.)  The refrigerant leaves as a high pressure liquid.
Vapour compression refrigeration system

Part 3: Throttling or Expansion Valve :   The liquid refrigerant is pushed through a throttling valve, which causes it to expand.  As a result, the refrigerant now has low pressure and lower temperature, while still in the liquid phase.  (The throttling valve can be either a thin slit or some sort of plug with holes in it. When the refrigerant is forced through the throttle, its pressure is reduced, causing the liquid to expand.)

Part 4: Evaporation:   The low pressure, low temperature refrigerant enters the evaporator, which is in contact with the cold reservoir.  Because a low pressure is maintained, the refrigerant is able to boil at a low temperature.  So, the liquid absorbs heat from the cold reservoir and evaporates.  The refrigerant leaves the evaporator as a low temperature, low pressure gas and is taken into the compressor again, back at the beginning of the cycle.

Vapour compression refrigeration system

Vapour absorption refrigeration cycle

Part 1. Absorption: Low pressure vapour of ammonia from evaporator is absorbed in a weak solution of aqua (liquid) ammonia in the absorber and thus gets converted into a strong solution. Strong solution of water and ammonia is pumped into a generator, while a weak solution returns to the absorber from the generator.

Part 2. Generation of High Pressure vapour: Strong solution pumped into the generator from the absorber is heated inside the generator. Ammonia separates in the form of vapour ammonia from the solution as the absorption of ammonia in water is at a lesser higher temperature. The weak solution is send back to the absorber. The high pressure, high temperature, ammonia vapours are then led to the condenser.

Part 3. Condensation:  High pressure hot ammonia vapours from the generator, are condensed in the condenser and high pressure liquid ammonia so formed is stored in the receiver.

Part 4. Expansion: High pressure liquid ammonia on its way to the evaporator passes through the expansion valve which reduces its pressure and temperature.

Part 5. Evaporation: The low pressure liquid refrigerant from the expansion valve, while passing through the evaporator, absorbs latent heat and converts it into low pressure vapour ammonia. Thus it produces a refrigerating effect in the space around the evaporator. From the evaporator the low pressure ammonia goes to the absorber and this way it completes one cycle of working.

Vapour absorption refrigeration cycle

TYPES OF REFRIGERATING UNITS IN HOTEL INDUSTRY

The usual categories of refrigerating units employed in the hotel industry are:

• Reach – in Units
• Counter – top or table – top Units
• Walk – in Units
• Special – purpose Units

Each of the above mentioned units can have both cooler and freezer sections in them. Some refrigerators are now divided into four zones to store different types of food. They are as follows:
Subzero (up to –18 degree Celsius) - Freezer Section
0 degree Celsius - Meat preservation Section
5 degree Celsius - Refrigerator
10 degree Celsius - Vegetables Section

Reach – in refrigerators

Coolers & Freezers – Capacities of such units are usually expressed in terms of the internal space volume (cubic metre) or in mass (Kg) of material being stored in it.
Typical interior temperature range for  cooler should be 4.4 degree Celsius to 7 degree Celsius and for a freezer should be -15 degree Celsius to -23 degree Celsius.

Counter top units

Small counter top refrigerators are frequently used to facilitate service.
They are usually coolers and have features similar to those of reach-in coolers but of much smaller size usually up to a size of 100 litres only.

Walk – in refrigeration system

As the name suggests, food operators can directly move into such units.
They are much bigger in size and height than walk – in refrigerators.
A typical size would be 4 X 5 X 3 m, or even more, or as lass as having a floor area of 2 sq. m..
They are normally custom built.

Special purpose units

Ice Cream Conservator and frozen food conservator: They are usually “well type” and open vertically through a lid. This minimizes heat loss as cool and heavy air inside cannot escape upward. They are usually maintained at temperatures between -23 to -18 degree Celsius.

Wet Fish Cabinets: They contain deep galvanized drawers in which fish can be embedded in ice. They keep moist storage conditions necessary for maintaining the quality of fish. They are usually maintained at temperatures between 0 to -2 degree Celsius.

Special purpose units

Display Cabinets: In many hotels, there is a refrigerated display cabinet kept in the dinning for the customers to choose varieties of meats for grilling. They are also used to display bakery products and desserts.
Bottle Coolers: They are used in dinning and are usually in bars. They are constructed in two ways. One is open refrigerated through type and the other is glass front cabinet type with hinged doors or sliding doors.
Ice makers:  Modern ice making machines need only to be connected to a cold water supply line. Water flows over a refrigerated plate and gets converted into a slab of ice. This slab of ice passes over a wire net which is electrically heated and the slab melts along the wire mesh and falls through the square holes as separate small cubes of ice.

CARE AND MAINTENANCE OF REFRIGERATING UNITS

Regular cleaning and maintenance not only makes your equipment work more efficiently, but it also helps it last longer. When parts are worn and dirty, the unit runs more frequently causing more wear and tear on the parts. Eventually, the unit breaks down for good long before it should have.
Preventing these issues is simpler than you think. Call in a qualified refrigeration service company at least twice a year and up to once a month, depending on the load and usage of your equipment, to do the following tasks:

• Clean evaporator and condenser coils
• Check lines for condensation
• Clean fan blades and inspect the fan motor
• Check integrity of insulation
• Check for air leaks through cracks, holes, and worn parts like gaskets and seals
• Lubricate door hinges and handles
• Check for loose electrical connections
• Clear drain lines of debris
• Check temperature and defrost settings and calibrate thermometers
• Check filters on ice makers
• Thoroughly clean all ice maker components

AIR CONDITIONING SYSTEM

What is Air Conditioning?
Any type of conditioning of air which includes circulating air in a room, filtering air, cooling or heating air, humidifying or dehumidifying air.
Complete air conditioning would mean all such processes being carried on air.
Refrigeration plant is necessary for such air – conditioning system.

Terminologies used in Air Conditioning

• Psychrometry – The study and measurement of the properties of air and water vapour mixture is known as psychrometry.
• Dry Air – Atmospheric air  consisting of a mixture of gases excluding its water vapour content is known as dry air.
• Moisture – The water vapour contained in air is called moisture.
• Moist Air – Atmospheric air along with gases and water vapour is known as moist air.
• Unsaturated Air – The moist air which does not contain the maximum amount of water vapour that it can hold at a given temperature is known as unsaturated air.
• Saturated Air – The mist air which contains the maximum amount of water vapour that it can hold at a given temperature, is known as saturated air.
• Dry Bulb Temperature (DBT) – The reading of temperature of air given by an ordinary mercury thermometer, having its bulb dry and not under the sun or other heat radiating objects.
• Dew Point Temperature (DPT) – At atmospheric temperature atmospheric air always contains water in form of vapours .If this air is cooled down, the water vapour is turned into water droplets. This temperature at which the water vapours turns into water droplets is called dew point temperature.
• Wet Bulb Temperature (WBT) – Temperature of air indicated by a mercury thermometer whose bulb is covered by a piece of wet muslin is known as wet bulb temperature.
• Specific Humidity (SH) -  It is defined as the total quantity of water vapour in the moist air.
• Relative Humidity (RH) – it is defined as the ratio of actual moist air content of a given volume at a particular temperature to the maximum amount of water vapour if the air is saturated at the same temperature.

PRINCIPLES OF AIR-CONDITIONING

The goal is to keep it more comfortable inside the house than it is outside.

Types of Air Conditioning Plants

• Centralized air – conditioning System

Unit air Conditioners

• Window type units
• Split type units

Centralised Air Conditioning Plant
The central air conditioning plants or the systems are used when large buildings, hotels, theaters, airports, shopping malls etc. are to be air conditioned completely.
The air conditioning system operates essentially in a closed cycle.
Return air from different spaces in the property such as lodging rooms, dinning areas, stores, banquet halls, kitchen etc. comes back through the return duct drawn by what is known as an extraction fan or exhauster.
This return air although a little stale is still cold/hot and relatively free from dirt and other contaminants present in fresh air.
Instead of exhausting the entire return gas out and sucking in fresh air only, it is returned to the circuit to minimize energy requirement for cooling/heating  and filtration.

Components of Centralised Air Conditioning Plant

1. FRESH AIR INLET – It admits fresh air through a louver/grille situated on an outside wall very much away from the kitchen, boiler house and water closet (WC) outlets.
2. FILTERS – It is employed to arrest suspended particulate matter such as dirt and dust from inlet air.
3. AIR WASHERS – This is the air – conditioning section which comprises of the pre-heater coil, refrigerating coil and banks of water sprays. The functions of air washers are to control humidity and clean air.
4. SCRUBBER PLATES – These are a series of zigzag plates with a stream of water running down them and are used to catch the dirt-laden water droplets coming out from the water spray section in the air washer.
5. WATER ELIMINATOR PLATES – These are a series of dry zigzag plates to remove any remaining free moisture in the air stream.
6. MIST ELIMINATOR – It is a metallic / non-metallic bed through which air is flown upwards. Fine mist is trapped in the bed and fall down as they coalesce (combine) to bigger size.
7. AIR HEATER -  This is composed of heating coils to bring the air up to the desirable room temperature, if necessary.
8. INLET FAN – It is a fan for drawing air through the inlet, ducting and forcing it into the various spaces in the building.
9. FRESH AIR INLET/LOUVERS – They are fitted in the inlet of the fresh air for uniform entry of fresh air and hence smooth mixing with return air before entry to the air – conditioning  section.
10. ROOM INLET GRILLES – One or more grilles in each room for the controlled inflow of air.
11. ROOM EXTRACTION GRILLES – One or more grilles in each room for the outflow of air. One to discharge outside into the atmosphere and another leading back to the AC plant inlet for the re-circulation.
12. EXTRACTION FAN – It is the fan for extracting air in the return path of the air ducting coming back from rooms and spaces.
13. CENTRAL EXTRACTION DAMPER – In case where complete central control is exercised a part of the return air from all spaces is discharged to the atmosphere through a control damper valve in the delivery side of the extractor fan.
14. DUCTING – Ducting is a term used to denote the passage for flow of air from the AC plant through various passages in the building opening into the closed space to be cooled and return to the inlet ducting in the AC plant. This also includes the ducting for exhaust to atmosphere.

Unit Air Conditioners – Window Type AC

• This is a completely self contained unit with the compressor, condenser, evaporator, refrigerant piping and air filter all assembled in a very compact manner.
• The window AC is usually 0.5 to 5 tons in capacity.
• Latest practice is to use sealed type compressor units so that possibility of leakage of refrigerant is eliminated.
• There is provision to control the fresh air intake.
• It is easy to install, operate and maintain.
• Its running cost is high.
• It requires at least one wall of the room free and open to atmosphere, so that the air is discharged in the open.

Unit Air Conditioners –Split Type AC

In this system, the cold side of the unit ( such as expansion valve, evaporator coil) is physically separated from the hot side (compressor, condenser).
The refrigerant flows through a long pipeline connecting the hot side and the cold side.
The cold part inside the room and the hot part outside the building.
The main advantages of split type air conditioners are:
Low cost for relatively larger size units
Absence of noise as the compressor is placed outside the building.

Building Transport System

Most multi storied hotels have many floors above the ground floor and also  one/two floors below the ground floor.
Hence appropriate and efficient building transport systems are not only important but necessary also for operation.
The systems should be a mix of manual and automatic operations.
There are two types of building transport system namely  Vertical Transport System and Horizontal Transport System.

Vertical Transport System

• Stairs
• Elevators / Lifts
• Escalators (Moving Stairs)
• Gravity Chutes (for goods)

Stairs
This is the most common and essential for vertical movement of people and goods.
It is also mandatory as it is an escape route in case of fire in buildings.
In case of power failure, lifts do not operate and hence stair case is the only alternative for vertical movement.
It must be fire proof so that guests can safely exit to upper and lower building floors.
Provision of hand rails and non-slip steps are recommended for safety purpose.

Elevators
An elevator is a transportation device used to transport people and goods vertically.
Elevators are generally automatic safety units for up and down transport purpose.
It consists of a platform travelling in vertical guides in a shaft with hoisting and lowering mechanism and a source of power.
The enclosure moving up and down in the guides is known as car.
There are two types of lift systems.

Cable elevators – They are more common because they are fast, smooth and quite.

Hydraulic elevators - are elevators which are powered by a piston that travels inside a cylinder. An electric motor pumps hydraulic oil into the cylinder to move the piston. The piston smoothly lifts the elevator cab/car. They are used when the number of floors to be serviced is less.
The elevators require regular inspection and maintenance and generally have a life of 20 years.

Escalators
The term escalator is a combination of elevator and “scala” the latin word for steps.
Escalators are the moving step type lifts operating at constant speed between two levels in an inclined course for moving large number of people in a short time.
It consists of a staircase whose steps move up and down on tracks which keep them horizontal.
Most escalators also have a moving handrail which approximately keeps pace with the movement of the steps.
The direction of movement (up and down) can be permanently the same or can be controlled by operators according to the requirement.
Generally two units are required side-by-side at each level, one moving upward and the other downward.


Gravity Chutes
Gravity chutes are used by hotels for transporting soiled linen, garbage and waste from different floors of the hotel to an outlet point (generally kept on the ground floor).
It is an efficient system as minimum power is involved in operating it.
Gravity chutes save workers motion, time and increase their productivity.

Horizontal Transport System

• Conveyor belts (moving sidewalk, moving walk way or travellator)
• Electric cars
• Manual trolley for transportation of luggage.

Travellators (Moving pavements)
Travellators also known as horizontal moving sidewalks, moving walkways is a slow speed conveyor belt to transport people, they can walk along or stand on it.
They are often installed in pairs, for movement in opposite direction.
Travellators may be used when there is substantial distance between the hotel entry point and the reception point.

Electric Cars
Electric car is an electrically operated open car with 6 to 8 seats.
This is an alternative to travellators and particularly very useful for disabled persons.

Manual Trolley
Manual trolley is used for transportation of luggage of guest.