Topic Wise Notes: Hotel Engineering
Please note: The answers provided below, are just for reference. Always consult your college professor if you have any queries.
Q.1. (a) Mention ten important duties and responsibilities of Chief Engineer of a hotel.
Duties & Responsibility of chief engineer
Planning of manpower requirements
Selection, training and job delegation of maintenance staff
Planning of duty roasters
Planning of smooth distribution of resources such as water, electricity, LPG etc
Planning and maintaining all the equipments and machinery of hotel
Reducing breakdown maintenance time
Improve preventive maintenance procedures
Implement and maintain energy saving plans of hotel
Preparing budget for maintenance department
Preparing work plans in co coordinating with other departments
(b) Describe briefly the complaint register-cum-work order system of fault rectification.
A Computerized Maintenance Management System (CMMS) Work Order may be a request for repair, restoration or replacement of equipment or asset. A Work Order request for a job that needs to be done can be scheduled or directly assigned to a technician. Work Orders can be generated by a customer request, internally within an organization, as part of a regularly scheduled maintenance program, or created as a follow-up to Inspections or Audits.
Q.2. Calculate the amount of electricity bill for the month of April 2013 for the following electric load, if the cost of electric energy is `3/- per kilowatt hour.
100 W electric lamps 80 Nos. 6 hrs./day 1.5 KW electric heater 2 Nos. 8 hrs./day 3 KW air conditioner 8 Nos. 8 hrs./day 5 KW boiler 1 No. 6 hrs./day
Energy used by lamos in one day= 100w*80*6= 48 kwh
Energy used by heater in one day= 1500w*2*8= 24 kwh
Energy used by boiler in one day= 5000w*1*6= 30 kwh
Energy used by Ac in one day= 3000w*8*8= 192 kwh
Total energy used in one day = 48 + 24 + 30 + 192 = 294 kwh
Total energy used in 30 days ( because April has 30 days) = 294 x 30 = 8820 kwh
1 kwh = 1 unit Cost per unit = Rs 3
Therefore, the bill for the entire month = 8820*3 = Rs. 26460
OR (a) Discuss the role of fuse in a circuit.
It is an over-current protective device with a circuit-opening fusible part that is heated and severed by the passage of over-current through it. A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented. Over current protection devices are essential in electrical systems to limit threats to human life and property damage. Fuses are selected to allow passage of normal current and of excessive current only for short periods. A fuse (Kit-Kat fuse) consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non- conducting and non-combustible housing. The fuse is arranged in series to carry all the current passing through the protected circuit. The resistance of the element generates heat due to the current flow. If too high a current flows, the element rises to a higher temperature and either directly melts, or else melts a soldered joint within the fuse, opening the circuit. Fuses act as a weak link in a circuit. They reliably rupture and isolate the faulty circuit so that equipment and personnel are protected. Following fault clearance they must be manually replaced before that circuit may be put back into operation.
(b) Discuss why earthing is important for an electrical appliance?
Earthing is an important component of electrical systems because of the following reasons: It keeps people safe by preventing electric shocks. It prevents damage to electrical appliances and devices by preventing excessive current from running through the circuit.
Q.3. State two scientific principles used in refrigeration. With the help of a neat sketch, explain the vapour compression cycle of refrigeration.
Vapour Absorption Refrigeration Systems: (VARS) belong to the class of vapor cycles similar to vapor compression refrigeration systems. However, unlike vapor compression refrigeration systems, the required input to absorption systems is in the form of heat. Hence these systems are also called heat operated or thermal energy-driven systems. Since conventional absorption systems use liquids for the absorption of refrigerant, these are also called as wet absorption systems. Since these systems run on low-grade thermal energy, they are preferred when low-grade energy such as waste heat or solar energy is available. As absorption systems use natural refrigerants such as water or ammonia they are environment-friendly. In the absorption refrigeration system, the refrigeration effect is produced mainly by the use of energy as heat. In such a system, the refrigerant is usually dissolved in a liquid. A concentrated solution of ammonia is boiled in a vapor generator producing ammonia vapor at high pressure. The high-pressure ammonia vapor is fed to a condenser where it is condensed to liquid ammonia by rejecting energy as heat to the surroundings. Then, the liquid ammonia is throttled through a valve to low pressure. During throttling, ammonia is partially vaporized and its temperature decreases. This low-temperature ammonia is fed to an evaporator where it is vaporized removing energy from the evaporator. Then this low-pressure ammonia vapor is absorbed in the weak solution of ammonia. The resulting strong ammonia solution is pumped back to the vapor generator and the cycle is completed. The COP of the absorption system can be evaluated by considering it as a combination of a heat pump and a heat engine
The job of the refrigeration cycle is to remove unwanted heat from one place and discharge it into another. To accomplish this, the refrigerant is pumped through a closed refrigeration system. If the system was not closed, it would be using up the refrigerant by dissipating it into the surrounding media; because it is closed, the same refrigerant is used over and over again, as it passes through the cycle removing some heat and discharging it. The closed cycle serves other purposes as well; it keeps the refrigerant from becoming contaminated and controls its flow, for it is a liquid in some parts of the cycle and a gas or vapor in other phases.
The metering device is a point where we will start the trip through the cycle. This may be a thermal expansion valve, a capillary tube, or any other device to control the flow of refrigerant into the evaporator, or cooling coil, as a low-pressure, low-temperature refrigerant. The expanding refrigerant evaporates (changes state) as it goes through the evaporator, where it removes the heat from the substance or space in which the evaporator is located.
The heat will travel from the warmer substance to the evaporator cooled by the evaporation of the refrigerant within the system, causing the refrigerant to “boil” and evaporate, changing it to a vapor. This is similar to the change that occurs when a pail of water is boiled on the stove and the water changes to steam, except that the refrigerant boils at a much lower temperature.
Now, this low-pressure, low-temperature vapor is drawn to the compressor where it is compressed into a high-temperature, high-pressure vapor. The compressor discharges it to the condenser so that it can give up the heat that it picked up in the evaporator. The refrigerant vapor is at a higher temperature than the air passing across the condenser (air-cooled type), or water passing through the condenser (water-cooled type); therefore that is transferred from the warmer refrigerant vapor to the cooler air or water.
In this process, as heat is removed from the vapor, a change of state takes place and the vapor is condensed back into a liquid, at a high-pressure and high-temperature.
The liquid refrigerant travels now to the metering device where it passes through a small opening or orifice where a drop in pressure and temperature occurs, and then it enters into the evaporator or cooling coil. As the refrigerant makes its way into the large opening of the evaporator tubing or coil, it vaporizes, ready to start another cycle through the system.
The refrigeration system requires some means of connecting the basic major components – evaporator, compressor, condenser, and metering device – just as roads connect communities. Tubing or “lines” make the system completely so that the refrigerant will not leak out into the atmosphere. The suction line connects the evaporator or cooling coil to the compressor, the hot gas or discharge line connects the compressor to the condenser, and the liquid line is the connecting tubing between the condenser and the metering device (Thermal expansion valve). Some systems will have a receiver immediately after the condenser and before the metering device, where the refrigerant is stored until it is needed for heat removal in the evaporator.
There are many different kinds and variations of the refrigeration cycle components. For example, there are at least a half dozen different types of compressor, from the reciprocating, piston through a screw, scroll and centrifugal impeller design, but the function is the same in all cases – that of compressing the heat laden vapor into a high-temperature vapor.
There are a number of different types of metering devices to regulate the liquid refrigerant into the evaporator, depending on the size of equipment, a refrigerant used, and its application.
The mechanical refrigeration system described above is essentially the same whether the system is a domestic refrigerator, a low-temperature freezer, comfort air conditioning system, industrial chiller, or commercial cooling equipment. Refrigerants will be different and the size of the equipment will vary greatly, but the principle of operation and the refrigeration cycle remains the same. Thus, once you understand the simple actions that are taking place within the refrigeration mechanical cycle you should have a good understanding of how a refrigeration system works.
OR Describe the installation, commissioning, proper use and care of an airconditioner.
Installation
If your local government requires permitting for the HVAC work, your contractor will either obtain the permit or inform you that you need to take care of it. In most cases, your contractor will do this for you.
The contractor will take apart and remove the existing air conditioner.
The contractor will install new duct systems or perform duct repairs.
Preparing the installation site. This may involve setting a concrete pad outside to support the air conditioner or installing rooftop supports for a packaged system installation.
Your new outdoor unit will be positioned correctly. The contractor will install it and secure it to the site.
If you are also replacing your air handler, install the indoor unit. While it’s a smart idea to replace both indoor and outdoor units at the same time, in some cases you may elect not to replace the air handler when you have a new outdoor unit installed.
Connecting the indoor and outdoor units. The contractor will determine the appropriate size for refrigerant lines, drain piping, and electrical lines. Some of these components link the parts of the split system.
Connecting the thermostat to the central air conditioner. You may have a new thermostat installed or continue to use your existing unit.
The vacuum will be pulled to remove contaminants from the refrigerant lines and charge the new central air conditioner with refrigerant.
The new cooling system will start and run.
The contractor will perform an installation inspection to ensure the installation was done correctly and the system functions properly.
Commissioning
The commissioning process begins with a thorough check of the HVAC equipment after it has been installed. A thorough check involves verifying the correct equipment and material has been installed and installed in the proper location. Then, we verify that installation meets construction details and manufacturer’s requirements. A custom checklist along with documentation of the installed equipment must be created.
After verifying the correct equipment and material has been installed, witnessing equipment operation is the next step. It is necessary to verify and document proper operation which includes the startup, shut down, and sequence of operation. Noting any issues of improper sequence of operations or start and shut down issues must be reported to the necessary contractors immediately. After the equipment has been verified to operate properly, the HVAC equipment can be tested, adjusted, and balanced (TAB).
Use and care
Inspect, Clean, or Change Air Filters Once a Month
Change your filters often in your central air conditioner, furnace, and/or heat pump. A dirty filter can increase energy costs and damage your equipment, leading to early failure
Schedule Seasonal HVAC Maintenance
Have annual system maintenance service performed one to two months before the summer season begins. Research shows that keeping your system clean and running effectively can save you over 20% on your heating and cooling costs
Clear the area around your HVAC system
Keep the condensing unit free of debris. Trim shrubs and plants near your air conditioning unit to ensure proper air flow and circulation
Clean Evaporator and Condenser Coils (once or twice a year)
The U.S. Department of Energy says that “a dirty condenser coil can increase energy consumption by 30%
Maximize Air Flow
Clean your vents and registers at least annually to help them circulate air as effeciently as possible
Install a Programmable Thermostat
Programmable thermostats can be programmed to change the temperature while you’re away or sleeping and can cut an energy bill by at least 10%
Q.4. (a) Mention ten steps that should be taken to make a hotel more fire-safe.
Provide adequate means of escape : The first rule of fire management requires sufficient escape routes out of the building, in accordance with its scale and occupancy. The number, size and location of exits are specified in the National Building Code (NBC) 2005, a detailed set of guidelines for constructing, maintaining and operating buildings of all types. Office occupiers must additionally ensure that staircases, stairwells and corridors are well-maintained, ventilated and free of obstacles in order to be effective in an emergency. Open spaces in buildings play a crucial role in fire management. As P.D. Karguppikar, joint chief fire officer of the Mumbai Fire Brigade, remarked after the terrorist attacks on 26/11: “The atrium in the old wing of the Taj (hotel) allowed heat to dissipate, and prevented collateral damage to other floors from the fire on the sixth floor.”
Outline clear pathways to exit doors : Getting to exits is as important as providing enough exits. NBC guidelines specify the maximum distance a person must travel in order to access a fire exit, and the importance of photo-luminescent signage to enable evacuation at night. Refuge areas such as terraces are critical for high-rises where people can safely congregate, when asked to leave the building in phases.
Install smoke detection systems : The first few minutes of a fire are crucial in containing it. Automatic fire alarm systems such as smoke and heat detectors are mandatory elements in international building codes, and particularly useful in spotting fires during times when occupancy in the building is low.
Maintain smoke suppression systems : Fire extinguishers are only useful if they work, so check them regularly. High-rise buildings, which are harder to access and evacuate, should consider installing automatic sprinkler systems. The National Fire Protection Association (NFPA), a US-based non-profit body, estimates that automatic suppression systems lower the cost of damage by 60%. Karguppikar endorses their use, admitting that “the fire in one of the rooms on the 18th floor of the Oberoi was extinguished by its sprinkler system and it was an eye-opener for all of us”.
Conduct regular fire drills : Preventing panic in an emergency is as important as staying away from flames and fumes. Regular fire drills familiarize people with emergency evacuation methods at little cost. Nominate a fire safety officer in every building to ensure that this becomes standard operating procedure.
Use flame-retardant materials in interiors : Materials used in the interiors can save or endanger lives. The combination of wood, paper and textiles makes workstations highly combustible. Fabrics can be made flame-retardant, however, so that they self-extinguish when lit. An increasing number of companies, especially multinationals, request such fabrics despite their price premium, according to data from Indian office furniture manufacturer BP Ergo. Stringent fire regulations abroad make it necessary for US furniture makers such as Herman Miller to provide only fire-tested fabrics. Doors are also assigned a fire-resistance rating, measuring how long they can remain resistant to excessive temperatures and flames without collapsing. Karguppikar lauds the construction of the fire-treated doors in the Taj, which allowed several rooms to stay insulated for hours despite a raging fire just outside.
Make your office accessible to firefighters : Grilled windows are a widespread urban phenomenon, and Jairaj Phatak, commissioner, Brihanmumbai Municipal Corporation (BMC), wittily observes that “residents who have grills on their windows presume that only thieves are kept out, and not firefighters”. Occupants of offices in residential buildings with few exits should be wary of locking themselves into confined spaces.
Keep the building plans handy : The tragedy at the Taj was heightened by the lack of buildings plans to guide rescue agencies. It is imperative to make multiple copies of your building plan available, especially during an emergency.
Ask the local fire brigade to assess safety : Fire departments, for a nominal fee, will independently assess your building’s level of fire safety. Storage of hazardous or inflammable materials, old and unstable structures, inadequate escape routes or electricity overloads are potential death traps that are best assessed by professionals.
Comply with National Building Code : “Green buildings” are in vogue but safe structures are sadly not. Both the Mumbai Fire Brigade and BMC commissioner concede that 80% of buildings likely violate accepted codes of building safety, with ignorance and personal whims leading to illegal modifications after gaining requisite occupancy permission.
(b) Classify different fires. Prepare a table showing different extinguishers used for different types of fire.
Class A | Wood, paper, textile, rubbish, grass etc. | Water is the best extinguishing medium for Class A. Some Dry Chemical Powder (DCP) are also used. |
|---|---|---|
Class B | Flammable liquids. (Oils, petrol, varnishes, paints, solvents, grease.) | Foam is the best extinguishing medium for Class B fires. Its reactivity should be ensured in case of Chemical fires. |
Class C | Flammable gases | Dry Chemical Powder is widely used for extinguishing gaseous fires. Its ability to cut the chain reaction in the combustion process makes it suitable for the purpose. |
Class D | Burning metal viz. Magnesium, Aluminium, Zinc, | Steam, Dry Chemical Powder be used against metal fires. |
Class E | Fires of electrical origin involving transformers, circuit breakers, switchgears | Dry sand may be used. CO2 type extinguisher to be used. DO NOT USE WATER. |
Class F | Cooking oil, fats (animal and vegetable) | Wet Chemicals to cool and emulsify. |
Q.5. Discuss the types of hardness of water. State the disadvantages of using hard water in hotels.
Temporary Hardness of Water:
The presence of magnesium and calcium carbonates in water makes it temporarily hard. In this case, the hardness in water can be removed by boiling the water. When we boil water the soluble salts of Mg(HCO3)2 is converted to Mg(OH)2 which is insoluble and hence gets precipitated and is removed. After filtration, the water we get is soft water.
Permanent Hardness of Water:
When the soluble salts of magnesium and calcium are present in the form of chlorides and sulfides in water, we call it permanent hardness because this hardness cannot be removed by boiling. We can remove this hardness by treating the water with washing soda. Insoluble carbonates are formed when washing soda reacts with the sulfide and chloride salts of magnesium and calcium and thus hard water is converted to soft water.
Disadvantages Of Hard Water
(i) Washing: Hard water, when used for washing purposes, does not lather freely with soap. On the other hand, it produces sticky precipitates of calcium and magnesium soaps. The formation of such insoluble, sticky precipitated continues, till all calcium and magnesium salts present in water are precipitated. After that, the soap (e.g., sodium stearate) gives lather with water. This causes wastage of soap being used. Moreover, the sticky precipitate (of calcium and magnesium soaps) adheres on the fabric/cloth giving spots and streaks. Also presence of iron salts may cause staining of cloth.
(ii) Bathing: Hard water does not lather freely with soap solution, but produces sticky scum on the bath-tub and body. Thus, the cleansing quality of soap is depressed and a lot of it is wasted.
(iii) Cooking: Due to the presence of dissolved hardness-producing salts, the boiling point of water is elevated. Consequently, more fuel and time are required for cooking certain foods such as pulses, beans and peas do not cook soft in hard water. Also tea or coffee, prepared in hard water, has an unpleasant taste and muddy-looking extract. Moreover, the dissolved salts are deposited as carbonates on the inner walls of the water heating utensils.
(iv) Drinking: Hard water causes bad effect on our digestive system. Moreover, the possibility of forming calcium oxalate crystals in urinary tracks is increased.
Q.6. Discuss different types of pollution related to a hotel.
Hotels and Water Pollution
Rampant discharge of wastewater and effluents into water bodies has played havoc with hygiene and ecology.
Wastewater disposal without proper treatment has severely affected marine life and living of downstream people using the water bodies for economic as well as day to day use of water.
Discharge of hot water also produces pollution in changing the aquatic environment of water bodies.
Hotels produce a lot of wastewater and many of them have now installed their own STP, which contributes greatly to reducing pollution as well as gaining economy by way of reuse of clear water.
This pollution can be minimized at the source by restricting chemicals that mix with water.
Hotels and Air Pollution
Hotels liberate gases and contaminated air from various utilities, such as kitchen gas and firewood ovens, fume from materials being cooked, boiler and diesel generating set exhausts, and release of refrigerant CFC, if there is any leakage.
If the boiler is fired with pulverized (powdered) coal, the exhaust gas will have a lot of dust particles leading to air pollution.
Diesel engines also produce pollutants such as carbon dioxide, carbon mono oxide and oxides of nitrogen.
Hotels and Soil Pollution
Hotels contribute to soil pollution by dumping their solid waste and sludge into the soil.
Excessive dumping of untreated or semi treated sewage and sludge may lead to contamination of soil and also produce a foul odor.
Hotels and Noise Pollution
Hotels have quite a few noises generating sources such as engines, pumps, motors, etc. And sound produced in banquet halls.
Liquid Waste (Sewage) its treatment and disposal
Hotels produce a lot of wastewater and usually, the wastewater is disposed of in water bodies such as river, sea, lake or as landfill.
But acc. to the norms of the PCB (Pollution Control Board), sewage needs to be properly treated before it is disposed of.
Q.7. Write short notes (any two): (a) Precautions for installation of gas bank.
Regular Maintenance: The gas bank must be regularly inspected by trained and certified engineers to avoid any malfunctioning of gas meters, pressure values or any other leakages.
Regulate Security Mechanism: Gas bank must have a state of the art security structure which must be covered by surveillance cameras linked to the security office of the apartment complex. Only the people associated with the gas bank maintenance team must be allowed entry into the gas bank.
Adopt Auto Shut off Operations: Auto shut off is a relatively new protective feature that must be embedded in housing complexes using old gas banks. Auto shut of features in this security tool work with sensors and can auto shut down the gas bank detecting any volumetric or pressure issues in gas supply to any part of the society. An auto shut down system can help have lives in case of an emergency of possible malfunctioning of the gas bank mechanism system
No Mobile Phones in Gas Bank: Mobile phones must be strictly restricted to not less than 10 meters radius from the gas bank as it can act as a catalyst leading to spiking of fire in the gas bank. The gas bank operatives must be certified professionals with prior experience in handling and maintaining such sensitive banks.
Restrict Unauthorized Entry: A lot of housing societies allow resident members to check the gas bank for their supplies in case the gas bank manager in not available. Allowing unauthorized entry of even residents can lead to a potentially dangerous situation. The housing society needs to make sure that the gas bank has at least one operational manager present 24/7.
Avoid Unnecessary Wiring: Gas bank must have very sensitive wiring and insulation. Any unnecessary wiring or loose connections must be avoided as it can lead to a possible explosion and fire. The best recommended to avoid any contact of electricity in the gas bank is to develop the gas bank as per the security protocols with proper insulation rather than using any other room or empty section in the building as a gas bank.
(b) Discuss types of fuels used in catering industry.
In form of its Geological existence:
Primary Fuel– fuels which occur naturally such as coal, crude petroleum and natural gas. Coal and crude petroleum
Secondary Fuel– fuels which are derived from naturally occurring ones by a treatment process such as coke, gasoline, coal gas etc.
In form of its state:
Solid Fuel– Commonly used solid fuels are firewood, coal and coke. Coal is used in broilers to produce heat. Coal/ coke/ wood is used in tandoor. Common solid fuels used in industry
Bituminous Coal
Anthracite
Lignite
Coke (Produced by heating coal in a closed oven unit)
Liquid Fuel– It is not widely used and may supplement main fuel in case of deficiency. They are majorly derived from petroleum. Commonly used liquid fuels are:
Kerosene
Light diesel oil (LDO)
High speed diesel (HSD)
Petrol
Furnace Oil
Gaseous Fuel– Commonly used gaseous fuels are:
LPG: used in cooking oven. It is liquefied petroleum gas comprising mainly butane (C4H10) and propane gas (C3H8). A small percentage of hydrocarbons is also present. It is aproduct of petroleum refinery. Traces of organic sulphide known as beta – mercaptan (C2H5SH) to trace leakage.
Natural gas: Methane (CH4) is the main constituent for natural gas and accounts for 95% by volume. Readily mingles with air and does not require any storage space
Producer gas or coal gas : obtained as a by product during production of coke
(c) Preventive measures for slips & falls.
cleaning all spills immediately
marking spills and wet areas
mopping or sweeping debris from floors
removing obstacles from walkways and always keeping walkways free of clutter
securing (tacking, taping, etc.) mats, rugs and carpets that do not lay flat
always closing file cabinet or storage drawers
covering cables that cross walkways
keeping working areas and walkways well lit
replacing used light bulbs and faulty switches
(d) Necessity for contract maintenance.
While contract maintenance may cover all possible types of maintenance including routine, preventive an corrective maintenance, some specific areas or circumstances might require contract maintenance as mentioned below.
Contract Maintenance may handle special needs of a property involving special equipment’s or when such needs are infrequent in nature.
E.g.: Fire Extinguishers, Lifts, Fire Alarm Systems, Detectors, Sensors etc.
Contract Maintenance may be called upon for routine services such as janitorial services for all sorts of building interior cleaning.
Ground maintenance and special maintenance needs like pest control activities (needing license from IPCA) are generally awarded to contract maintenance.
In many properties, operation and maintenance of water treatment, sewage treatment and swimming pool maintenance are left to contract service owing to their very sophisticated nature.
At small establishments, air – conditioning and refrigeration units are also maintained through contract service.
Special equipment’s are often needed for cleaning kitchen ducting, grease trap, grease filters etc., and their maintenance is also often contracted out.
Q.8. Explain in brief (any five):
(a) B.T.U. : The British thermal unit is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units.
(b) Open circuit : an electrical circuit that is not complete.
(c) Methods of heat transfer :
Convection: The process in which heat is transmitted from a hotter part of a body to a colder part by the actual movement of the material of the body is called convection.
Conduction: The process in which heat is transmitted from a hotter part of a body to a colder part without any visible movement of the material of the body is called conduction.
Radiation: the process by which heat is transmitted from one place to another without the help of any material medium or without heating the intervening medium is called radiation.
(d) Fluorescent lamp : A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow.
(e) Solid & liquid waste : Solid, liquid, or gaseous by-products resulting from human biological processes, manufacturing, materials processing, comsumption of goods, or any other human activity.
(f) Automatic fire detector : The basic purpose of an automatic fire alarm system is to detect a fire in its early stages, notify the building occupants that there is a fire emergency and report the emergency to first responders.
(g) Group replacement :
There are certain categories of equipment that normally do not require maintenance activities while in service.
During their lifetime, they operate and give service more or less to the design level and then fail suddenly.
Eg: Electric lamps, MCB’s, sensors, detectors, washers, valves, etc.
Q.9. A Choose the appropriate option:
(i) Measurement of light is given in: (a) Joules (b) Volts (iii) Lumens (iv) Ampere (ii) In chilled water air conditioning applications, the temperature of chilled water is maintained at: (a) 0ºC (b) 7-20ºC (iii) 15ºC (iv) 5-5ºC (iii) Paying money one time to repair 10 faulty water taps is a: (a) Lumpsum contract (b) Annual contract (c) Monthly contract (d) Cost plus contract (iv) Heat is absorbed by a refrigerator during refrigeration cycle in: (a) Condenser (b) Compressor (c) Evaporator (d) Throttle valve (v) In India the single phase voltage for domestic supply is: (a) 220-240 Volt (b) 110-130 Volt (c) 380-415 Volt (d) 415-460 Volt
B Explain: (a) AC and DC
Alternating current is defined as the flow of charge that changes direction periodically. The result obtained will be, the voltage level also reverses along with the current. Basically, AC is used to deliver power to industries, houses, office buildings, etc.
In a DC circuit, electrons emerge from the minus or negative pole and move towards the plus or positive pole. Some of the physicists define DC as it travels from plus to minus.
(b) Calorific value of fuel
The calorific value of a fuel is defined as the quantity of heat (expressed in calories or kilo calories) liberated by the complete combustion of unit weight (1 gm or 1 kg) of the fuel in air or oxygen, with subsequent cooling of the products of combustion to the initial temperature of the fuel. The calorific value of a fuel depends upon the nature of the fuel and the relative proportions of the elements present, increasing with increasing amounts of hydrogen. moisture if present, considerably reduces the calorific value of a fuel. the calorific value may be theoretically calculated from the chemical composition of the fuel.
(c) One ton of refrigeration
A ton of refrigeration, also called a refrigeration ton, is a unit of power used in some countries to describe the heat-extraction capacity of refrigeration and air conditioning equipment. It is defined as the rate of heat transfer that results in the freezing or melting of 1 short ton of pure ice at 0 °C in 24 hours.
(d) Preventive maintenance
Any activity which is carried out on the machinery or the equipment when any default is noticed and it seems that because of that fault the machine is not functioning well and may go out of order in the future is termed as a preventive maintenance.
(e) MCB
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected.
Q.10. List and explain use of security equipment in hotel industry.
1. 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 guest room, guest bathroom, public area, and back-of-the-house location.
Smoke and heat detection units also vary in their characteristics; some have the ability to report a heat buildup prior to evidence of smoke or flame, while others respond only to smoke and other products of combustion.
Automated systems, which integrate all smoke detectors in each location with a master panel, permit staff to immediately determine where a smoke detector has activated and to respond accordingly.
Many local jurisdictions enacted regulations requiring fully automated smoke detector systems in all new construction and the retrofitting of smoke detectors for all lodging establishments.
2. Fire Extinguishers:
There are four classes of fires that a lodging property should be prepared for
1) Class A fires involve ordinary combustibles,
2) Class B fires involve flammable liquids,
3) Class C fires involve electrical equipment, and
4) Class K fires involve cooking oils and fats.
Tips: Although some jurisdictions will permit the elimination of fire extinguishers in a facility with a full sprinkler system, consideration should still be given to the use of extinguishers as they would permit the fighting of incipient fires rather than waiting for a fire to generate enough heat to activate an automatic sprinkler system.
3. 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.
4. Sprinkler Systems:
Sprinkler systems are now mandated in an establishment four stories or higher, adhering to the Hotel and Fire Safety laws on each country. This requires a system covering back-of-the-house, public, and all guestroom locations.
Most jurisdictions now require full sprinkler systems in the new construction of any commercial occupancy regardless of the height of the structure.
5. Accident Prevention Signs:
OSHA 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 colour for identification of all danger signs, which include restricted area, in case of fire, do not enter, and emergency exit signs.
Caution signs: should only be used to warn against potential hazards or to caution against unsafe practices. The colour 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 remodelling 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.
OR Explain the reason under which equipment are replaced.
1. Demand for more number of equipments: This situation arises when the existing number of a particular type of equipment cannot meet the full demand of the hotel. Eg: A bigger DG Set is to be installed as the small DG sets installed earlier cannot meet the full demand and there is no physical space for an additional DG set. Hence the only option is to go in for a bigger DG set.
2. Excessive and frequent maintenance: When the equipment and devices become old, they need frequent maintenance. The frequency of maintenance becomes more and more with the passage of time and more money is spent. Sometimes non availability of spare parts makes maintenance impossible. In such situations, replacement becomes the only option.
3. Advanced Technology Technological advancement is a continuous process and in a short span, we get improved version of the equipment with new technology. Latest technology equipments become an added attraction for guests and customers. Hotels also replace equipments to remain in business competition.
4. Decreasing Efficiency Sometimes with time, old equipments do not give the required efficiency. No amount of maintenance work helps to improve their efficiency.
5. Due to failure Some equipments breakdown all of a sudden.
6. To maintain symmetry Some equipment needs to be replaced to maintain the symmetry.
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