SCHOOL OF ARCHITECTURE, BUILDING AND DESIGNS

BACHELOR OF QUANTITY SURVEYING (HONOURS)

BUILDING SERVICES 1 (BLD60403)

Submission Date : 22/6/2015

Group Members : DAVIN YOUNG QIAO WEI (0321065) GAN JET FOONG (0315998) LAI CHOON FENG (0315898) LEE PUI SUN (0314584)

NA YEOW SING (0320385) NG JIA NAN (032059)

Lecturer : Leong Boon Tik

List of Group member’s work

No. Type of Work Name

1 Introduction NA YEOW SING

2 Type of hot water supply system NA YEOW SING

4 Installation process NG JIA NAN

5 Management system LAI CHOON FENG

6 Advantages and Disadvantages NA YEOW SING

7Case study : The Royal Orchid Sheraton Hotel, Bangkok, Thailand

DAVIN YOUNG QIAO WEI

8 Possible problems to the system LEE PUI SUN

9 Recommendations for future improvement GAN JET FOONG

10 Conclusion LEE PUI SUN

11 References LEE PUI SUN

Table of Content

No. Content Page

1 Introduction 1

2 Type of hot water supply system 3

4 Installation process 11

5 Maintenance 17

6 Advantages and Disadvantages 20

7Case study : The Royal Orchid Sheraton Hotel, Bangkok, Thailand 22

8 Possible problems to the system 26

9 Recommendations for future improvement 29

10 Conclusion 32

11 References 33

1

Introduction

An adequate supply of pure water has already become one of the prerequisite in our

daily life. Try to imagine what it would be like for you if did not have readily available supply of

water for drinking, bathing and cleaning purposes. Hence, a completed water supply system is

essential for a building.

The common water supply systems are cold water system and hot water system. The

purpose of the water supply system is to provide the enough hot and cold water to the

occupants. Before water is distributed throughout the water main systems to individual

premises, it must be treated to get rid of any water-borne bacteria, microorganisms or

suspended organic. Water companies are responsible to guard against the pollution of main

water supplies and water quality to their consumers.

In current hot water system design, multiple hot water system is the preferred approach

in hotel industry. The key advantage of multiple hot water system is isolating the guestrooms

from heavy instantaneous equipment demands, especially laundry equipment. In some hotels or

corporate buildings, they require large amount of hot water for guestrooms, laundry, kitchen

application and etc. The various types of hotel facilities have different requirements for hot water

usage. The hotel industry today recognizes essentially 11 different types of accommodations is

shown in Table 1. A review of the data at the bottom of Figure 1 reveals some interesting

information about the nature of hotel hot water consumption.

Typical Occupancy(persons per room)

Hot water characteristic

Back-of-house requirements

Deluxe 1.2Largest per capita water consumption.

Full food service, full laundry, extra towel load.

Luxury/first 1.2 to 1.3 High per capita hot water Full food service, full

Type of Facility

Table 1 – Hot water use in lodging facilities.

Figure 1 – Natural of hotel hot water consumption.

Times average flow

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class full service

consumption. laundry.

Mid-scale/full service

1.2 to 1.3High per capita hot water consumption.

Full food service, full laundry.

Convention 1.4 to 1.6Peaks during conventions. Similar to luxury.

Banquet facilities, multiple kitchens, full laundry.

Limited Service

1.1

Guestroom load dominants. No ballrooms, meeting spaces.

Limited food facilities, kitchenettes in suites, sometimes uses outside services.

Upscale all-suites

2.0Longer stays by guests. Laundry units use more water.

Limited food facilities, kitchenettes in suites, full laundry.

Economy all-suites

2.0 to 2.2Longer stays by guests. Lower consumption than upscale all-suites.

Limited food facilities, kitchenettes in suites.

Resort 1.9 to 2.4Higher consumption. More evenly distributed throughout the day.

Full food service, expanded beverage operation, full laundry, larger guest load.

Conference center

1.3 to 1.4Guestroom facilities and kitchen usage are not consistent.

Full food service, full laundry.

Casino 1.3 to 1.4

Activity peaks in evening hours. Heavy hot water usage due to multiple shower.

Full food service, extensive beverage operations, full laundry and heavier uniform laundering.

Economy 1.6 to 1.8Short stays. Low consumption/minimal services.

Limited or no food service. Many have no laundries.

Type of hot water supply system

Designing and maintaining a suitable hot water system for today’s hotel industry is

important. The consideration on desgining a hot water systems included quantity of hot water

required, cost of installation and maintenance, fuel energy required, available municipal water

pressure and safety of the user.

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Types of Hot Water Supply System

Localised

Instantaneous water heating

system

Storage water heating system

Centralised

Direct System

Electric Water Heating

Gas Storage Water Heater

Boil-Cylinder System

Instantaneous System

Indirect System

With expansion vessel

Vented storage

Unvented storage

Others

Solar Heating System

Figure 2 - System selection flow chart

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Localized hot water supply system

With this type of system, the water is heated locally to meet the requirements of the

consumer. The localized system is usually used where a long distribution piperun from stored

system would waste the time to wait for hot water to drawn off. Commonly, this system may use

gas-fired water heater or electric heater in order to save energy and reduce wastage of water. It

also helps to prevent the risk of growth of microorganisms.

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Figure 3 - Hot water supply system for high rise building usually divided into two or more zones to prevent excessive pressures on the draw-off points.

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Instantaneous water heater system :

The water heaters can be sized to generate as much hot water as is needed at

any moment in time.

This system provides hot water at a rate of 2-5 gallons (7.6-15.2liters) per

minute. Gas-fired water heaters can produce higher flow rates than electric water

heaters.

If the hot water demand is excessive in a building, it can install separate

instantaneous water heaters for appliances in order to overcome the problem of

not enough hot water supply for simultaneous uses.

Does not require too much storage space.

Storage water heater system :

The heaters can be sized to generate hot water at rates which are below the

largest demand rate.

These heaters are located near a sink and the capacity not more than 15 liters.

Use storage tanks to set up the difference between momentary demand and the

water heater’s capacity.

This systems usually be used when the buildings require large amount of water

at intervals, large fluctuation of required quantity and reliable supply.

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Pressure switch

6kW Heating element

Rod thermostat

Casing

Hot water outlet

Cold water

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Centralized hot water supply system

With this type of system, the water is heated in a boiler and the hot storage vessel and

cold water storage cistern linked by supply and circulatory pipework. The boiler usually close to

the hot water storage vessel in order to reduce pipework heat losses. Furthermore, the water

stored in a vessel until required and water temperature is controlled by a thermostat. The

temperature of the water should be stored inside the vessel at least 60°C so that it reaches a

temperature of 50 °C within one minute at the outlets. For most people, the risk of scalding at

this temperature is low.

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Figure 4 - Instantaneous gas water heater.

Hot water outlet

Cold water

Figure 5 - Instantaneous electric water heater.

Figure 6 - Details of storage water heater. Figure 7 - Storage water heater with heavy Guage copper tank.

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Direct system:

Typical water heaters found in many homes, restaurants, and hotels.

The water is heated in a boiler with oil, gas or electric and circulated to a hot

water storage cylinder.

The difficulties of this system is oxygen and fur products are constantly

introduced to the system and lead to corrosion and a boiler explosion.

An alternative to this system is indirect system.

Indirect system:

The principle of indirect system is similar to the direct system except the water

from the boiler is circulated through a coil in the vessel through the primary flow

and return pipes.

Heat is transferred from the water in the coil to the water surrounding in the

storage tank.

The object of using this system is to separate circuit in the boiler, radiators and

the water in the circuit does not mix in any way with the drawn off from the

storage vessel.

This system can avoid the build-up of fur in the boiler, primary flow or return

pipes caused by the precipitation of salts from temporary hard water.

Indirect systems can be fired by gas, oil, propane, electric, solar energy, or a

combination of any of these.

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Solar Heating System

Solar water heating system is a simple and reliable system. Solar systems belongs to

the low-temperature heat applications. A solar water heater is a combination of a solar collector

array, an energy transfer system and storage tank. Solar collector array is the major part of

solar water heater which absorbs solar radiation and converts it to heat. After that, the fluid that

passes through the collector will absorb the heat. This heat can then be stored or used directly.

Human can collect the solar energy from the sun through nature (or passive) systems or active

systems.

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Figure 8 - Direct hot water system.

Figure 10 - Indirect hot water system. Figure 11 - Indirect cylinder.

Figure 9 - Direct water cylinder.

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Passive System Active SystemThermosiphon (direct and indirect) ;

Integrated collector storage.

Direct system system ;

Indirect circulation systems, internal and

external heat exchanger ;

Air systems ;

Heat pump systems ;

Pool heating systems.

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Table 2 – Seven types of solar energy systems can be used to heat domestic and service hot water.

Figure 12 - Passive direct system. Figure 13 - Active direct system.

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Installation process

Although the hot water supply system is quite easily to be understood in theoretical

studies, but when it comes to practical, the installation process of the hot water supply is quite

complicate to be done. There are few considerations needed to be made before the starting of

installation process to achieve a well-planned installation.

First and foremost, the type of hot water system needed to be choose. There are two

types of hot water system; centralised or localised system. Different type of building required

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Figure 14 - Passive direct system

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different type of hot water system. For commercial building like hotel, it is more convenient and

effective to have a centralised hot water system. This system is suitable for hotel because of the

high water consumption of hotel. Centralised hot water system tank can store a large amount of

hot water, it shows a great contribution to the hotel during the consumption of hot water is at its

peak. For office building where the consumption of hot water is low, localised system is more

suitable to be installed.

Capacities of boilers is also one of the consideration. For hot water supply in a domestic

premises having a storage capacity of approximately 120 litres, it is usual to allow 3kW boiler

power. If the scheme is combined with space heating a suitable allowance must be added. Oil

and gas-fired boilers are generally more efficient than solid fuel. A certain amount of deposit

from the products of combustion is left on the boiler flueways but provided it is removed when

the boiler is serviced, little loss of efficiency will result. These two fuels also have the advantage

in that they can be controlled electrically and can therefore be operated automatically and can

therefore be operated automatically to a greater extent than solid fuels. They do, however,

require much more specialist attention and unlike solid fuel boilers involve the householder in an

annual maintenance charge.

The effectiveness of the boiler flue has a considerable bearing on the efficiency of any

boiler whatever type of fuel is used. Flues should be lined to prevent condensation forming, a

very important consideration when oil or gas appliances are used, owing the low temperatures

of the flue gases. The formation of the throat of a flue in the case of a solid fuel back boiler must

be carried out observing the manufacturer’s recommendations in order to obtain the maximum

efficiency from the appliance without waste of fuel. The throat is the portion of the flue which is

narrowed or reduced in size immediately above the appliance, creating a positive updraught.

The connection of the flue pipe of an independent boiler to the stack should be made as shown

in Figure 18. This method allows the flue pipe to expand and avoids cracked plaster where it

enters the chimney. A soot door should also be provided externally to enable the chimney to be

swept.

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Before fitting a boiler consideration should be given to its position in relation to the

suitability of the surrounding building fabric as a boiler support and its fire resistance. Reference

must be made to the Building Regulation for details of the requirements for hearths and flues.

Competency in gas work is very important. It should be noted that only plumbers and

fitters who are qualified in the installation and servicing of gas appliances are allowed to carry

out gas fitting, as poor-quality work and lack of knowledge can result in dangerous situations,

the only exception to this being where gas work is carried out on by certified gas fitters or DIY

enthusiasts must comply with the Gas Regulations which are enforceable by law.

Regulation 71 of the Water Ordinance,1994/ Water Supply Regulation, 1995, stated that

every hot water pressure vessel or tank shall be constructed of stainless steel, copper or other

materials approved by the State Water Authority and shall comply with the Standard listed as

Item 33, 34, 39, 40 and 42 in the First Schedule.

Hot water storage vessels. These must now comply with the updated British Standards

BS 1566 and 3198. Those labelled P are only suitable for pumped primary systems. Type G are

suitable for both pumped and gravity systems. They are usually cylindrical in shape to enable

them to withstand higher internal pressures. The maximum listed capacity is 440 liters. Vessels

of larger capacity than this would not be economically viable due to the required increase in the

thickness of copper. In commercial buildings where more storage is required, galvanized steel is

used for greater strength. Stainless steel vessels complying with BS EN 150 9002 are becoming

more popular, especially for unvented systems, as this material is stronger than copper and can

better withstand the higher internal pressures common to such installations. It is not good

practice to mix galvanised components and copper in the same system if it can be avoided

because of the possibility of electrolytic corrosion.

Storage vessels should be sited as near as possible to the boiler to reduce heat losses

from the circulating pipes and ‘dead legs’ should be as short as possible. A dead leg is a run of

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Figure 18 - Connection of flue pipe from independent boiler to chimney.

Figure 19 - Recommendations of Building Regulations Approved Document Part J: Flue pipes for solid fuel and oil appliances.

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pipe from the hot storage vessel to a drain-off point and most draw-off pipes in small domestic

properties are in face dead legs. Long dead legs will result in waste of water and heat due to the

amount of water having to be drawn off before hot water reaches the tap and the subsequent

heat losses from the hot water remaining in the pipe gradually cooling when the tap is closed. It

is important to make provision for air movement under the storage vessel by standing it on

battens. Failure to do this may result in the formation of condensation, causing damage to

wooden or chipboard flooring.

Indirect cylinders, this is to say that water heated in the boiler is circulated in the storage

vessels and will be eventually drawn off through the taps, resulting in a continuous change of

water. This is acceptable when the water is for domestic use only, but if the scheme is

combined with central heating, an indirect cylinder must be used. The object of using an indirect

cylinder is to separate the water in the boiler, radiators and associated pipework, the primary

circulation, from that actually drawn off through taps. The only reason water has to be supplied

to the primary circulation after the initial filling of the system is to replace losses due to

evaporation. The use of an indirect cylinder avoids the build-up of fur in the boiler and primary

flow and return pipes caused by the precipitation of salts from temporary hard water. It also

avoids any corrosion problems that could occur with continually changing water coming into

contact with radiators made of ferrous metals. Heat is imparted to the water in the storage

vessel by a coil or annulus, the coil being preferred owing to the higher pressures developed in

fully pumped and pressurized systems of combined hot water and heating supplies. A coiled

tube is deemed more efficient than an annulus and so less heating surface is required for the

same performance.

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Potential areas for water efficiency improvements in a typical hot water installation

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(a) cylindrical (b) combined unit

Figure 20 - Hot water storage vessel.

Figure 21 - Indirect hot water cylinder. This type of hot storage vessel is used on indirect systems of hot water supply to reduce corrosion and scale formation in hard-water areas.

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Feed cistern, this is the term given to the cistern which feeds the domestic hot water

supply system to distinguish it from the feed and expansion cisterns used in indirect hot water

supplies and from cold water storage cisterns. In most domestic properties, however, where the

cistern feeds the cold water services it also serves as a feed cistern for the hot supply. Its

minimum nominal capacity, for hot water supply only, should not be less than 114 litres plus the

amount required for cold water storage if it is used as a dual-purpose storage vessel. Hot

storage vessels are graded in relation to the thickness of the material from which they are made

and the internal pressure which they can withstand, as can be seen from Table 3.

Vessel GradeTest pressure

(kN/m²)Max working

head (m)*

Copper cylinder to BS 3198 and 1 365 251566 2 220 15

3 145 10Galvanised steel cylinders to A 483 30

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BS 417 B 276 18C 138 9

*The maximum working head if vertical distance between the base of the storage vessel and the water line of the feed cistern.

Table 4 - Hot water storage capacities for small dwellings.

No. of bedrooms Storage in litres

2 1203 1444 166

Table 4 shows suggested hot water store capacities for domestic properties based on the number of bedrooms.

All types of appliance must be fitted to comply with the manufacturer’s specification. The main

points to bear in mind are as follows:

(a) Check that sufficient air for combustion is available.

(b) Ensure all seals on the appliance are airtight, this is especially important in connection

with convector fires.

(c) The ‘throat’ of the flue with open fires must comply with the dimensions in the installation

guides. It is usually defined as the point at which the appliance actually joins the

chimney. It does not apply to appliances connected to the chimney via a flue pipe.

On completion of solid fuel installation the customer must be made aware that:

(a) The operation of any air inlet controls may vary according to wind conditions causing a

variation on the pull of the flue.

(b) It is essential that the recommended grade of fuel is used.

(c) All flueways must be kept clean.

Maintenance

Even though water systems periodic maintenance, they are generally not a major

consumer of maintenance time or cost unless they deteriorate to the point of needing major

work or replacement. The preventive maintenance activities involved with water systems include

such tasks as treating water to make it suitable to the application or need, replacing sacrificial

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Table 3 - Grading of hot storage vessels.

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anodes (which decrease pipe corrosion) in water heaters, cleaning filters and strainers,

lubricating pumps, checking hot water temperature settings, checking pressure relief valves on

water heaters for proper operation. In addition, guestroom maintenance consists of the repair of

leaking valves and general caulking and sealing around fixtures.

Besides that, in the fall and all through the warming season, facility manager and owner

likewise need to vent or cleanse radiators that don't have a programmed cleanse framework. To

vent the radiator and channel the evaporator, take after these headings: Open the valves on

radiators and convectors to let out air to keep them open until water begins turning out. Be

prepared to catch the water in a basin or holder, close the valve to deplete the evaporator to

dispose of rust and mineral stores and read the producer's directions, kill the force and water to

Instead of the old cast-iron radiators, today's units have detached or baseboard convectors.

They're less massive, more effective, and look much more pleasant than their precursors and

they give the same measure of warmth to all the rooms. The disadvantage of hydronic or hot

water heat is that, on the grounds that there is no ventilation work, you can't have focal air, stick

the end of a garden hose into the boiler drain cock, open the vent valves on a radiator situated

on the top floor of your home to this gives air access to the channels which, in turn, makes the

water drain through the framework, turn on the water supply valve so crisp water will flush

through the framework to the valve is situated on the water funnel going into the heater and

When the water quits running, close the channel chicken and vents to the water will keep

streaming into the kettle and through the framework despite the fact that they're closed.

A facility manager and owner should be conscious of the potential for corrosion and

erosion of water piping systems. Corrosion is the destruction of a metal or alloy by chemical or

electrochemical reaction with its environment, erosion is a literal wearing of a pipe’s inner

surface due to friction.

There are many types of corrosion possible such as the pH of the water, the amount of

oxygen in the water, the amount of galvanic corrosion from the use of dissimilar metals within

the piping system and the temperature of the water.

Facility managers can test the water’s pH to determine whether the supply is overly

acidic overly alkaline and requires treatment. Highly oxygenated water (recirculating fountains)

may also be quite involved, with a number of different chemicals contributing to the water’s

corrosive potential. Salts are corrosive; managers and others involved with maintaining

swimming pools recognize the corrosive potential of the chlorinated water used in pools.

Galvanic corrosion occurs when different metals come in contact with each other. Finally, any

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corrosion will occur at a faster rate as the temperature of the water increases. Corrosion is also

possible on the exterior of pipes, particularly those that are buried underground. In these

instances, there may be a reaction between the pope and the soil/ fill around the pipe, or there

may be a leakage of ground water into the soil/fill around the pipe (especially troublesome is the

salt-laden runoff from streets and parking areas that have been salted to clear them of snow

and ice).

Erosion of the piping system is another concern. Turbulence in water systems (resulting

from water flowing at high velocity, pipe turns, and obstacles) causes a wearing of pipe surfaces

and of protective oxides produced on the inside of copper piping. Water velocities in excess of

four feet (1.22 meters) per second should be avoided. A factor that can accelerate pipe erosion

is the presence of particulates (sand, metals filings, and so on) in the water itself. Adequate

filtering of the water should help to keep these at a minimum.

The flame of fossil-fueled water heating appliances should be inspected periodically to ensure

that proper combustion is taking place. The flue should also be checked for blockage. All water

heating units should be inspected regularly for water-side mineral buildup and periodically

cleaned and drained to reduce this buildup. If this is not done, the unit’s efficiency and lifetime

will be reduced.

Wastewater systems may require periodic clearing to reduce the chances of blockages

ad resulting backups. Traps may require periodic filling with water at some locations (such as

floor drains in generally dry areas). Gutters, roof drains, and site drainage, all of which enter the

storm sewer system, should be inspected and cleaned of debris. This can be particularly

important before times of the year when heavy rains occur and when debris, such as aerating

faucets (that is, faucets that spray water through a screen that spreads the flow). When

problems occur, clogged drains need to be cleared either chemically or mechanically. When

maintenance staff work on plumbing in guestrooms, they should also inspect the tile and caulk

around the plumbing fixtures and perform any necessary repairs.

Emergency and breakdown maintenance of water systems requires knowledge of the

key water shutoff valves, the piping layout for both potable and waste water, and the appropriate

cleanup equipment. Such equipment includes, at a minimum, a wet/dry vacuum and usually a

pump as well.

Furthermore, there are numerous methods for counteractive action of erosion

channeling. A few strategies for minimizing disintegration erosion incorporate enhancing the

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stream lines inside of the funnel by deburring (i.e. - smoothing out anomalies), permitting twists

to have bigger points, and changing funnel distances across progressively as opposed to

unexpectedly. Different routines incorporate moderating the stream rate (minimizing turbulence),

diminishing the measure of disintegrated oxygen, changing the pH, and exchanging the funnel

material to an alternate metal or amalgam. Notwithstanding the liquid way material utilized, it is

additionally critical to consider your liquid's temperature. At higher temperatures, stream rates

ought to be brought down to minimize disintegration erosion. The most ideal approach to battle

erosion is to anticipate it as adequately as could be expected under the circumstances. The

conditions that permit consumption to happen can be controlled and erosion lessened by the

correct usage of steam traps, air vents, and operational systems – particularly amid shutdown -

to keep air and water from responding. Legitimate water treatment and close checking of

condensate pH levels are likewise basically vital variables to help anticipate consumption.

Ultimately, it is critical to fare thee well in selecting funneling and traps in view of the particular

conditions and requirements for your framework. In frameworks that frequently shutdown,

paying little mind to what extent the shutdown period commonly keeps going, condensate may

stay in the framework and blend with air, taking into consideration the progression of erosion. By

totally depleting the arrangement of condensate at shutdown time, the movement of erosion can

be significantly reduced.

Advantages and Disadvantages

In the hotel industry, hot water is used for ranging from guest showers to laundry. The

cost to heat water always exceeds the cost of the water that is heated. Depending on the fuel

sources used for water heating, the cost of the heat can range from 4 to 20 times the cost of the

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water. So nowadays, solar water heating systems are becoming increasingly popular in the

hotel industry. There are some advantages and disadvantages about this system.

Advantages Disadvantages

Solar energy is produced by conducting the sun’s radiation so it can reduce the use of fuels and achieve environmental friendly.

This system is not suitable for the places where a lot of rains and cloudy for example Paris and Portland.

Cost effective.The initial cost is higher than others conventional hot water heaters.

The installation of this system is simple and require low maintenance.

Large area of rooftop is required to capture the sun energy.

It is clean energy source and renewable. Require overheating and freeze protection.

Having long life and gives value for your investment. A solar water heater can be used up to 20 years.

Require a larger storage tank than conventional hot water heaters because the temperature of the solar collector is lower than a typical gas hot water heater.

Comparison between the centralized systems and localized systems.

Centralized systems Localized systems

Require large storage space. Fitted close to fittings.

Long length of secondary pipework will cause large heat losses.

If the number of heaters is added means more connection point.

One central plant implies simpler and less maintenance.

Reduce the size of boiler and fuel storage.

Better control in energy consumption. The risk of fire will increase.

Reduction in flue construction.Structural or architectural aspects may restrict the use of cheaper fuel.

Advantages and disadvantages of instantaneous water heater system.

Advantages Disadvantages

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Does not require too much space. It can be placed almost anywhere in the house.

The heaters must be sized carefully. If the heater is undersized, the water temperature and water flow will be affected.

Unlimited hot water supply, as long as fuel is present.

High energy-demand cost.

Having long life and gives value for your investment.

High initial cost. This type of water heaters will cost you twice as much as conventional storage tanks.

Reduced risk of water damage. Need to wait longer to obtain hot water.

Advantages and disadvantages of storage water heater system.

Advantages Disadvantages

Smaller demand on the gas/power.Occupy more space. When the hot water demand is high, as additional storage tanks may be required to meet that demand.

Low maintenance cost.During high usage times, it is possible of running out of water.

Simple installation and replacement.Limited hot water supply. You can supply only as much hot water as your storage capacity.

Less risk of being without supply. Risk of pipes freezing in winter.

Case Study, The Royal Orchid Sheraton Hotel, Bangkok, Thailand

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Brief Summary of Hotel

The Royal Orchid

Sheraton Hotel has

more than 30 years of remarkable history after Her Majesty Queen Sirikit graciously agreed to

lead over the hotel’s opening on July 22, 1983. This hotel is the first Sheraton hotel in Thailand

with 726 guest rooms and suites. The Royal Orchid Hotel is considered one of the finest hotel in

Bangkok making them tourists’ top priority when it comes to accommodation.

Old Hot Water Supply System

Since the operation began in 1983, the hotel’s hot water supply system adopts a water

heating system which is powered using fuel oil. The system had 2 boilers, one which is on

stand-by. Each boiler has the capability to produce 5 tons of hot water per hour and the average

fuel consumption is approximately 2,000 litter per day. The system also consist of 5 hot water

generator which uses steam as the only heat source. Moreover, the hot water supplied for

domestic usage is about 55°C and the average consumption is roughly 95 m3 per day at 70%

occupancy.

The old hot water supply system is very inefficient and has many disadvantages, among

them includes the price of fuel oil increasing from time to time. This does not just increases the

cost of the hotel but could also be a long term burden to the business.

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In addition, using fuel oil as source of energy is very non eco-friendly as we all know that

burning of fuel releases carbon monoxide and carbon dioxide. Besides that, fuel oil is non-

renewable and non-energy efficient source.

Current Hot Water Supply System

When the price of fuel oil increased to more than 25 Baht per litter (approx. US$0.7/litter)

in 2008, it was very clear that using the old system is very non-economical and a burden to their

business. Hence, the management of the hotel decided to switch to solar water heating system.

This does not just save cost but in addition there was an incentive from the Department of

Alternative Energy Development and Efficiency (DEDE) which awarded the hotel with a subsidy

of 4,500 Baht/m2 of solar collected area.

In 2008, DEDE launched a solar heater subsidy programme. This programme is only

applicable commercial hybrid system where the government will award incentives to companies

which has a minimum of 40m2 of solar collector area per project with the use of waste heat from

air conditioners, boilers, etc. Thailand’s solar heater subsidy programme aims to promote a

greener and better Thailand and this programme will continue until 2021.The programme

launched by DEDE was also another main factor that the hotel decided to switch to solar

heating system.

The current Solar Heating system used by Royal Sheraton Hotel is by SETatWork and

this system consists of 360m2 of flat plate solar collectors, 2 hot water storage tanks with a

capacity of 23,000 litters, circulation pumps, and control system. The system can produce hot

water about 24,000 litters/day at an average temperature of 55°C.

How it works?

Since this system is solar powered, it has every reason to be placed on the concrete roof

top and operates automatically using differential thermostat. When the temperature of the solar

collector is being heated to about 10°C higher than the storage tanks, the circulation pumps are

turned on and are turned off when the temperature difference drops to 5°C. Hot water from the

storage tanks flows to the heat exchangers where the water will heated using solar energy and

discharged to the existing hot water piping system. The figures below Figure 22 and 23

illustrates a schematic diagram of the system and photo of the installation respectively.

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The hotel also installed 5 units of heat pump

to produce additional hot water to meet the demand

as shown in figure 24. Each unit has a capacity of

1,500-2,000/hour at 20-30°C/unit. The heat pump

will only function when the temperature of the solar

heated water falls below a certain point which is

usually during dusk and night time. This way, there

will always be sufficient hot water in the storage

tank ready to be used by the hotel customers. Each

pump is capable of producing about 2,000 litter

/hour at 50°C and consuming a rated power of 18.8kw.

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Figure 22 –Schematic diagram of solar water heating system.

Figure 23 – Flat plat solar collectors on the roof top of Royal Orchid Sheraton Hotel.

Figure 24 –Heat pump on the roof top.

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Safety Feature

Like most industrial water heating system, this particular system has an expansion tank

(figure 1). An expansion tank is relatively important as water expands when is gets heated and

thus increasing the pressure of water. In extreme cases, the pressure might just be too high for

the pipe to contain which results in the pipe bursting. The expansion tank is filled with

pressurised air and it will absorb any excess water pressure. As water fills the tank it will

compress the compressed air.

Comparison between old water heating system (fuel powered water heater) and current water heating system (solar water heater).

Solar Fuel oil

Cheaper annual cost There is limited use of electricity

hence electrical bill is cheap. The only time electricity is used is during night time when there is no sunlight.

It does not just safe cost but incentive is given from the Department of Alternative Energy Development and Efficiency (DEDE) which awarded the hotel with a subsidy of 4,500 Baht/m2

of solar collected area.

Higher annual cost. Bill on fuel supply is higher The price of fuel increases every year

as it gets scarce as time goes on.

Eco-friendly Does not emit any pollutants such as

CO2

Solar energy is reusable hence no natural resources is wasted.

Non eco-friendly Fuel oil is non-reusable Non energy efficient Emits CO2 & CO

Suitable for large quantity usage More consumption more cost

Large storage is needed Less storage space is needed

Verdict

The current solar heating system does not just save on cost but the hotel also get

incentive in return. Solar heating system is super eco-friendly, does not use a single bit of

earth’s resources and does almost no harm to the environment. In addition, the solar heating

system can produce hot water more efficiently and it is suitable for large quantity usage such as

hotels.

In conclusion, Royal Sheraton Orchid Hotel invested their money well on SETatWork

solar heating system which is much better than the water heating system they had before.

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Problems occur having hot water supply in hotel/corporate building

Hot water supply is important to everyone in every buildings, especially in hotels and

corporate buildings. However, problems of hot water supply always occur in the buildings such

as the absence of hot water, water is too hot, noises appear while using hot water, having

backpressure backflow and leakage of water.

Insufficient Hot Water

Water leakage is one of the reason the hot water supply system does not have enough

hot water. Natural minerals are consisting in the water. They can be calcified into sediments and

remain still in the water tank. The sediments can create cracks in the water tank and causing

the water to flow out. Apart from this, water expansion due to being over heated can cause

pressure in the tank and making cracks. Sometimes, the pressure occur in the tank can be

caused by the faulty of Temperature & Pressure Relief Valve (T&P Valve) since this valve is a

safety device that keep out from excessive temperature and pressure levels.

Damaged dip tube is also a fault of insufficient hot water supply. Dip tube placed inside

the water heater. Its function is to send the cold water to the bottom of the tank, where it heated

the cold water up. Defective dip tubes will fall to pieces into the tank and create effect on acidity

levels of water and temperature settings, which make the hot water to only lukewarm.

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Figure 25 - Cross section water heater.

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Water Being Too Hot

If the water is too hot, temperature setting may be the problem of it. A dial indicator

exists at the water heater thermostat that controls the temperature of water. The higher setting

on dial indicator will cause the temperature of water being too high, so it is best to check the dial

indicator and make an adjustment on it. Besides that, the formation of minerals from the water

that cannot be removed from purification process sank to the bottom of the tank or cover of the

water heater elements. This problem causes the water tank hard to heat water. Overheated

elements will also release the heat into the water and create overheated water.

Thermostat can goes wrong as a red reset button set off id the thermostat has been shut

off power to the elements during routine cycling. Thermostat works to manage the on and off

cycle of water heater elements. The elements in the water heater will keep on heating the water

if the thermostat has been broke down and this cause the water temperature rise over a safe

level.

Noises can be heard

Ticking and creaking sounds can be heard from the water. The reason of these noises

are due to the cold metal pipes like copper tend to expand and rub against its surrounding items

when the hot water flows through the pipes. To stop the noises, the copper pipes should be cool

off and then they will start to shrink if the hot water stops flowing through the pipes.

Besides that, popping noise also can be heard with a reason of formations of minerals in

the water. The minerals produce a coarse coating inside the pipes, and causes air bubbles to be

form and burst once the water being heated up. Apart from this, the flowing of water through the

pipes generate pressure and this issue creates the vibration from loosely attached water pipes.

Therefore, rattling noise has been produced when the pipes vibrate against the surrounded solid

objects.

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Backpressure backflow

Backpressure backflow occurs when the water supply has connected to a high pressure

system. The temperature of the water will surely increase very much if the pressure of the

system is higher and causes the water being forced to flow backwards. Contaminated or

polluted water can be flowed in to the pipes in the building; people in the building also do not

know that the water is not clean and caused health issues.

To prevent backpressure backflow happened, backflow preventer is used as air gap get

rid of a cross-connection or supplies barrier to backflow. An air gap is “a vertical, physical

separation between water supply outlet and floor-level rim of a receiving vessel” (Lincoln Water

System in USA). The length of the separation has to be at least twice the diameter of the water

supply passage, although there is a risk that air gap can easily be bypassed.

Water Leaking

Hot water supply can also have the problem of water leaking. The leakage of water

happened due to the corrosion of piping system where the pH value in the water supply is lower

than 8. The acidity of the water supply dissolves the copper oxide film, which copper oxide film

is on the pipe walls. Copper oxide film acts as a barrier to reduce the corrosion of the copper

pipes. When the copper oxide film dissolves, the barrier disappears from the pipe walls and

changes the water to corrosive ones.

Excessive pressure in the water tank will cause the water heater starts to leak. To be

precise, the Temperature and Pressure Relief Valve (T&P valve) leaks, and it relieve the excess

pressure in the water heater. The water in the tank expands when heated up, and being pushed

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Figure 26 - Backflow preventer.

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back out of the house. The water that has been heated up gets trapped and formed pressure in

a closed system. The T&P Valve then leaks out water due to the pressure being piled up in it.

Recommendation for Future Improvement

Use mainly heat pump water heating

A heat pump is highly efficient because it does not produce the heat it distributes.

Instead, it transfers the heat from the air outside to the water stored inside the heater through a

heat exchange system. It is safe, efficient, and also eco-friendly. It can produce same volume of

hot water while the running cost of heat pump water heaters is only 1/2 of solar water heaters,

1/4 of electric water heaters and 1/3 of gas water heaters. Therefore, this makes heat pump

systems much more efficient than solar, electric and gas water heaters.

Benefits

• A system that uses less energy than standard electric cylinders.

• Heat pump water heaters can function in places that have less or no sunlight.

• Can take advantage of cheaper night-rate electricity based on Economy 7 tariff that

charge night costs less than the electricity during the day.

How does it works?

Heat pump extracts heat from surrounding air and optimized to add heat to water. The

actual efficiency of a heat pump water heater depends on the quality of the installation,

the temperature of the place and the location of the compressor unit.

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Types

There are 2 types of heat pump water heater:

• Split systems

Split systems have the compressor unit outside and the hot water tank generally inside although

the tank can also be located outside the house separate from the compressor.

• All-in-one units

All-in-one units have the compressor and tank together. However, the whole system is usually

sits outside.

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Advantages

• Suitable for a hot climate country because the hotter the outside air, the better the heat pump

functions.

• The tanks of heat pump water heaters can be customized according to requirements

• Heat pump water heaters only required heat energy from ambient air

• Heat pump water heaters do not get affected much by rainy days and cloudy days

• Easy operation and hot water keeping constant temperature.

• The source of energy is always available, safe and eco-friendly. There are no burning and gas

emission.

• Heat pump water heaters can be installed indoors and outdoors, makes it convenient to install.

• Heat pump water heaters also can controlled remotely.

• Long lifespans and low cost of maintenance.

Disadvantages

• The upfront cost of heat pump water heating is relatively expensive. This is because the global

heat pump water heater industries are still in the early stage, so the qualities of heat pump water

heaters are various.

• Initiate costs are higher than other water heaters.

Return on Investment

A 180 kW capacity heat-pump installation that produces 100 m3 (100,000 liters) of hot water per

day would require an investment of approximately US$160,000 (5.4 million Baht).

If the average hot water consumption of the hotel is about 95 m³/day at 70% occupancy, the

daily use of hot water would cost US$ 232 (7,813 Baht) per day or US$ 6,960 (234,416 Baht)

per month with heat pumps.

Conclusion

A heat pump doesn’t need solar panels, thus able to save large amount of installation

and maintenance cost. Using heat pumps also save considerable amount of cash on hot water

bills because it use approximately half of solar water heaters

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Heat pumps can replace fuel boilers that are used in the hotel to provide steam to the

laundry. After replacing the fuel usage for hot water, it can be considered to replace that last bit

of fuel usage with leaner, cleaner and cheaper electrical steam boilers or small gas-fired boilers.

In the end, choosing the right system that use less hot water helps reduce your energy

costs and make a real difference.

Conclusion

Throughout this assignment, we learnt a lot about the details of hot water supply and the

sources of water heated in hotels or corporate buildings. There are different types of common

energies for water heating. Besides that, we also studied that two systems of hot water supply

existed, Electrical Heating System and Solar Heating System. In the category of Electrical

Heating System, there are also two types of it, Instantaneous Water Heater (as known as Tank-

less Heater) and Storage System. The two types of Electrical Heating System have their own

benefits and shortcomings, which we do not know much about them. We search a lot of the

installation process by websites and books in library to get more information and understand

more of it, as well as the management system of hot water supply.

Not only these, we too found out the problems occur when having hot water supply and

reasons of these problems. The problems we learnt from our resources are more to our

knowledge, but the curing or prevention methods are less to our expectations. To recognize

more about hot water supply, our group done a case study of The Royal Orchid Sheraton Hotel

in Bangkok. We stated out the recommendations for future improvements if we think the

buildings are needed to do so. We also received some advices or slight changes from our

lecturer, Mr. Leong to improve our assignment. Words of advice can make a better changes for

this assignment.

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References

Books:

Stipanuk, D. M. (2002). Hospitality facilities management and design. 2nd ed. East

Lansing, Mich. : Educational Institute, American Hotel & Lodging Association, c2002.

Blower, G. J. (2002). 4th ed. Plumbing : mechanical services. Book 1. Harlow, England :

Pearson / Prentice Hall, 2002.

Blower, G. J. (2002). 5th ed. Plumbing : mechanical services. Book 2. Harlow, England :

Pearson / Prentice Hall, 2002.

Websites:

GreenMatch (2014). 5 Advantages and 5 Disadvantages of Solar Energy. [Website]

Retrieved from http://www.greenmatch.co.uk/blog/2014/08/5-advantages-and-5-

disadvantages-of-solar-energy

The Building Engineer (2009). Tank-type vs. Tankless Water Heaters. [Website]

Retrieved from https://buildingengineer.wordpress.com/2009/10/08/tank-type-vs-

tankless-water-heaters/

The National Board of Boiler and Pressure Vessel Inspectors (1998). Boiler/Burner

Combustion Air Supply Requirements and Maintenance. [Website] Retrieved from

http://www.nationalboard.org/index.aspx?pageID=164&ID=236

Reflex (n.d). Hot Water Storage Tanks & Heat Exchangers. [Website] Retrieved from

http://www.reflex.pl/admin/wyswig/pliki/esklep1/pliki/PI1309en_9571358_Warmwassersp

eicher-Waermeuebertrager.pdf

Home Guides (n.d). Troubleshooting an Overheating Electric Hot Water Heater.

[Website] Retrieved from http://homeguides.sfgate.com/troubleshooting-overheating-

electric-hot-water-heater-73980.html

Ace Plumbing (2014). What Causes a Leaking Water Heater? [Website] Retrieved from

http://www.aceplumbing.com/plumbing-faq/What_Causes_a_Leaking_Water_Heater

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Websites (cont’d):

Energy and Environment Cabinet (2011). Division of Water- Backflow and

Backsiphonage [Website] Retrieved from

http://water.ky.gov/DrinkingWater/Pages/BackflowBacksiphonage.aspx

Home Guides (n.d). Causes of Noisy Hot Water Pipes. [Website] Retrieved from

http://homeguides.sfgate.com/causes-noisy-hot-water-pipes-89095.html

RedBeacon (2015). How to Fix a Leaking Water Heater Guide. [Website] Retrieved from

http://www.redbeacon.com/hg/how-fix-leaking-water-heater-guide/

Global Solar Thermal Energy Council (2014). Thailand: Ministry of Energy Extends

Incentive Programme until 2021. [Website] Retrieved from

http://www.solarthermalworld.org/content/thailand-ministry-energy-extends-incentive-

programme-until-2021

SET at Work – Sustainable Energy Technology at Work (2010). Good Practice: Solar

Water Heating System, Royal Orchid Sheraton Hotel, Thailand. [Website] Retrieved from

http://www.setatwork.eu/database/products/R165.htm

NORTHERN IRELAND COAL ADVISORY SERVICE (n.d). Your Guide To Curing

Chimney Troubles. [Website] Retrieved from

http://www.coaladvisoryservice.com/resources/files/yourguidetocuringchimneytroubles_l

ow_res.pdf

Hot Water Supply (n.d). [Website] Retrieved from

http://www.angelfire.com/co4/pfnotes/Hot_Water_Notes.pdf

HotWater 101: Installing a Thermal Expansion Tank (n.d). [Website] Retrieved from

http://www.whirlpoolwaterheaters.com/media/32672/st-gas-elect-

thermalexpansiontankinstall.pdf

Martin, A. (2013). Heat Pump Water Heating. [Website] Retrieved from

http://www.energywise.govt.nz/products-and-appliances/water-heating/heat-pump

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Tan, L. (2012). Advantages and Drawbacks of Heat Pump Water Heaters. [Website]

Retrieved from http://www.heat-pump-industry.info/advantages-and-drawbacks-of-heat-

pump-water-heaters.html

Websites (cont’d):

Hedstrom, G., Hedstrom, P., and Tremore, J. O. (2013). How To Maintain Hot Water

Heating System. [Website] Retrieved from

http://www.dummies.com/how-to/content/how-to-maintain-hot-water-heating-

systems.html

TLV – A Steam Specialist Company (2015). Erosion in Steam and Condensate Piping.

[Website] Retrieved from http://www.tlv.com/global/TI/steam-theory/piping-erosion.html

LYTRON – Total Thermal Solutions (2015). Erosion-Corrosion in Cooling System.

[Website] Retrieved from

http://www.lytron.com/Tools-and-Technical-Reference/Application-Notes/Erosion-

Corrosion-in-Cooling-Systems

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