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Unit 11 Managing Building Services within the Construction Environment
 



Introduction

Section 1. Organising and Managing Services

Section 2. Essential Services

Section 3. Specialist Services


 
 

 

Information and Guidance is available on how you should study

 

Study Guide
 


 


Assignment for Unit 11



Before Sunmitting your assignment you MUST read 
 

Instructions for

Submitting Assignments



 

Additional Learning Resourses

Constructionsite

 


 






 
Additional Information

You should relate your responses to any of the tasks set in this unit to the documents listed below; these will provide information about the type and size of the project.  











































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Section 2







































































































































































































































































































































































































































































































 
 

































































































































 


































































































































































































































































































































































 
Section 3

















































































































 
 
 
Unit aim: This unit is designed to meet the needs of Construction Managers, to give them knowledge of managing building services.
 


This unit has an Introduction and is divided into 3 study sections.

Introduction

Section 1 Organising and Managing Services

11.1.1 Site Requirement for Services
11.1.2 Function of Building Services
11.1.3 Design of Service Systems
11.1.4 Building Information Modelling (BIM)
11.1.5 Manage Building Services on Site
11.1.6 Testing and Hand-Over
 

Section 2 Essential Services

11.2.1 Low and High Pressure Water Systems
11.2.2 Drainage and Sanitation
11.2.3 Electrical Lighting and Power
11.2.4 Heating
11.2.5 Gas Installations


Section 3 Specialist Services
 
11.3.1 Mechanical Ventilation and Air Conditioning
11.3.2 Fire Prevention Systems
11.3.3 Security Systems
11.3.4 Communication Systems
11.3.5 Transportation Systems


Unit Recommended Reading

Hall, F & Greeno, R, (2009) Building Services Handbook; Oxford: Elsevier


Books can be ordered from most bookshops or online from Amazon.


Studying
 
Before starting you should read the ‘Study Guide’ accessible from the link on the left.
 


Introduction

In order to manage building services you will need to understand the main factors relating to them.  You will need to understand the different services that can be installed in buildings, the purpose of each, their design aspects and how they function.  In this unit you will be introduced to these factors, the systems and how they are installed.

The aim of services is to make life more comfortable and convenient for the buildings occupiers and users. It will create and maintain a desired standard of comfort of a physical environment. It will therefore ensure that the occupants have hot and cold water, the removal of waste products and a level of comfort with regard to warmth. It will also provide means of transportation around a building and in the protection for the building and its occupants. This will entail the consideration of safety and ensuring that the building services do not present a risk to the buildings and anyone who uses it. Consequently each service will have a raft of legislation to ensure that it is installed in a manner which ensures that it does not present any form of danger or risk and these must be adhered to. They are part of the regulations involved with the installation of each service.

This unit is not designed to teach the regulations for each service merely to provide an introduction to the services. For more details the student should consult the Building Regulations or specific books related to each service. Additional guidance can be obtained from the constructionsite which is accessible from the Resource page.

We start this unit by looking at Organising and Managing Services which can be reached by clicking on the link below.
 
                  

Please Note

All information contained in this Study Unit was considered correct at the time of writing but Students must not rely on information contained in the Study Unit and/or references for any purposes other than use within this CIOB qualification aim as legislation and working practices are constantly being revised and updated. Students are advised therefore to continually up-date themselves as to current legislation and construction practice and must not to rely on information contained within the Study Unit and/or references for practical applications in the workplace. Where legislation or construction practice has been superseded to that contained in the Study Unit Students should note this within their responses to the tasks.
 


Section 1. Organising Services

Learning outcome: On completion the learner will know how to determine the service requirements for a project.


Contents

11.1.1 Site Requirement for Services
11.1.2 Function of Building Services
11.1.3 Design of Service Systems
11.1.4  Building Information Modelling (BIM)
11.1.5 Manage Building Services on Site
11.1.6 Testing and Hand-Over


 
11.1.1 Site Requirement for Services

During the construction phase there will be a need for services to enable the process of construction to take place; this will include Water, electricity and telephone and is something the site manager will need to consider. During the planning of the site it is worth considering these requirements in order that the siting of the service provision takes into consideration the positioning of the buildings requirements in order to utilize these and to save in the temporary service installations. It is always better to lay the service for the building which can then be tapped into on a temporary basis where ever possible. 

 

11.1.2 Function of Building Services

The main function of the services system is to create and maintain a desired standard of comfort of a physical environment. This will, therefore, ensure that the occupants have hot and cold water, the removal of waste products and a level of comfort with regard to warmth. It will also provide any additional services such as power, communications and a means of transport around a building should that be required.

The purpose of the utility provision within a building is to provide these utilities at the point of use. It must deliver the required service at the required point and be able to provide sufficient capacity for the requirements of users. These must be delivered in a safe and convenient manner taking into account the likely requirements of other users of the building in order to ensure that sufficient is always available. The design of any system must therefore consider:
  • The utilities that are required or might be required
  • Size of the building
  • Use of the building and the activities which are to be undertaken requiring utilities
  • Loading Requirements – what it is needed for and for what time duration, are the requirements spaced evenly over the day or at specific periods.

The design requirements are set out according to the Building Regulations, Codes of Practice, British and European Standards. The Building Regulations can be accessed from the website listed below.

In determining the requirements the designer should also be aware of the costs of the utilities in order to appraise the factors in deciding which utilities will be used i.e. should heating be provided by gas, electricity or oil.

Prior to the design it will be necessary to understand the basic needs for the comfort of the building users and the measures which will provide those needs. If you are unclear on this you can visit the constructionsite unit Thermal Comfort and the Transfer of Heat.

The type and number of services will vary according to the type of building and its use. Generally some form of fire protection will be needed either as a warning system or to deal with a fire should it occur. Security systems are now part of a building’s design and dependent on the type and building layout. Some form of transportation system may be required; this may be an elevator or escalator. For specialist buildings such as hospitals or communication centres specific services will also be needed.

The design of any system must consider that rising demand, water pollution and climate change has an important influence on the environment so the designer must implement measures to reduce the environmental effects that the building will have.

Another factor which must be considered is the integration of the services into the building and the design to allow for this, the way that this is done is shown in Chapter 15 of the unit recommended book.

 


Task 11.1.1 Site Managers' Role

Discuss the role of the site manager in the planning and installation of site services.

Word Guide:  300 – 400

 

11.1.3 Design of Service Systems

The building services will be designed by the Building Services Engineer who will work with the client and the architect to ensure that the client’s requirements for the building are met. In order to do this it is essential that the client’s needs for the building are analysed.

 

Analysing Clients Needs

Before any system can be designed it is necessary to understand the function of the building and analyse the requirements of the building owner and the occupants. The size will also have an effect on the design of the systems required as it will dictate the size and layout of system being used.

You will need to understand the factors with regard to the building environment so you should start by reading the Chapter 1 of the Building Services Engineering book specified for this unit.

The next step is to ensure that you understand the basics relating to the provision of services and their requirements, something that we will do in the next two sections of this unit.

 
 


Task 11.1.2 Design of Services

Produce a list of the types of information that will be needed to enable the Building Services Engineer to design the services for a building.

Word Guide:  300 – 400

 

 
11.1.4  Building Information Modelling (BIM)

 
BIM is an acronym for Building Information Modelling, or Building Information Model. It is a system used to describe the process of designing a building by the use of computer models rather than as separate sets of drawings and is produced collaboratively by all those involved in the process of construction.
 
BIM combines technology and a set of work processes. A process which must mean everyone who is involved working together. The process involves data capture, information modelling and information management in a collaborative environment, where all teams involved work together to the same standards. The graphical information is shown in the form of a 3D model. It also shows non-graphical such as programmes, cost and facilities and asset management. It also enables components within a model to be tagged with relevant data.
 
BIM brings together all of the information about every component of a building, in one place. It makes it possible for anyone to access that information for any purpose, e.g. to integrate different aspects of the design more effectively. In this way, the risk of mistakes or discrepancies is reduced, and abortive costs minimized. It offers gains in saving in cost and time, much greater accuracy in estimation, and the avoidance of error, alterations and rework due to information loss. 
 
The use of BIM goes beyond the planning and design phase of the project, as it extends throughout the building life cycle and supporting processes, including cost management, construction management, project management, and facility operation.
 
BIM was brought to the industry’s attention in 2011 by the publication of the UK Government Construction Strategy.  Take up of BIM is slow but more development work is being undertaken. 
 
 
 


Task 11.1.3 BIM

Discuss the advantages and disadvantages of using BIM 

Word Guide: 300-400 
 
 

11.1.5 Manage Building Services on Site

The building services installations are in most cases carried out by a specialist sub-contractor, although the main contractor’s site manager will be responsible for ensuring that they are on site according to the programme and that the work is carried out as specified.

One way of ensuring that the work is carried out correctly is to have a checklist to confirm it is acceptable.

 


Task 11.1.4 Check List

Prepare and use a check list to monitor the progress of installation work for an aspect of building services for your company.

Word Guide: 100 – 300

 

 
11.1.6 Testing and Hand Over

Prior to handing over the work it will need to be tested to ensure it is safe, functional and meets all requirements. Each type of service will have its own requirements with regard to testing and these must be complied with. The site manager must ensure that all tests are carried out by a competent person according to the requirements and are recorded prior to hand over.

 
 


Task 11.1.5 Testing

Using an installation of your choice, explain how this would be commissioned and tested and how the results would be recorded. Explain the handover process to the client.

Word Guide:  200 – 300

 
 

 
 
Section 2. Essential Services

Learning outcome: On completion the learner will know the essential services for a building.


Contents
 
11.2.1 Low and High Pressure Water Systems
11.2.2 Drainage and Sanitation
11.2.3 Electrical Lighting and Power
11.2.4 Heating
11.2.5 Gas Installations
 


11.2.1 Low and High Pressure Water Systems

Design

The design of the system to be incorporated into a building will depend on the:
  • Number and type of fittings to be supplied
  • Maximum water flow
  • Spacing and location of fittings
These will depend on the type of building and their frequency of use; it will also depend on the likelihood of the number of fittings being used simultaneously and the demand required by these.

In order to calculate this requirement a unit loading rating is used together with a recommended minimum rate of flow for each type of appliance.

 

Pipe Sizing and Lengths

In order to meet the required flow rate at the appliance a number of factors need to be considered, these are:
  • Head of water available
  • Length of the pipe
  • Diameter of the pipe
  • Smoothness of the internal bore of the pipe
An allowance is also made for any frictional resistance caused by fittings such as elbows and tees.

The diameter of the pipe is determined for the required flow rate and the maximum length which is allowable. Details relating to these are found in the Hall & Greeno book recommended for this unit.

Water used direct from the main is required for each unit (dwelling, rented unit) in order to provide drinking water. In large buildings and in some areas of the country the remaining water requirements are provided by storage. In high rise buildings water will be stored at various levels which will reduce the static water pressure.

In order to ensure the distribution of drinking water this too is stored though in order to reduce the risk of contamination sealed storage tanks are used. Details regarding requirements for potable water in low pressure systems can be found in the book Building Services Engineering listed below.

 

Low Pressure System

A low pressure system works on the basis of storing water which is used to provide the appliances. This requires a storage facility to provide sufficient water for a 24 hour period. There is a requirement that water in storage tanks is of a similar quality to that provided from the mains so they need to ensure that contamination does not occur they also need to ensure that there is stagnation within the system.

In tall buildings the tanks may be situated at a level above the height that the pressure in the mains can lift it to, in such a case it will be necessary to install a pressure boosting system in order to lift the water.

 

Mains Connection

Individual dwellings connect to the water main by a Goose neck and communication pipe. The pipes may be of lead (found in old building), copper or plastic. Lead will become brittle with age and is liable to crack.

Certain soil conditions are likely to cause corrosion in metal pipes, ie. wet ashes, decomposing matter particularly if drainage is bad and there is a high sulphate or chloride content. In such case pipes will need protecting.

Pipes must be at a minimum depth of 750mm for frost protection.

 

Stop Taps

Stop taps should be fitted at the point of entry of the water supply into the building, in addition to the Water Authorities onto the cartilage and to enable each appliance to be isolated.

 

Types of Cold Water Distribution Systems

Direct or Non-storage

All the plumbing fittings are supplied with cold water direct from the mains. A cold water cistern is normally used to feed the hot water supply system though water heaters are available which can be fitted direct from the mains.
 Figure_11
Figure 11.2.1 Direct System of Cold Water Supply

Key:
1,2, 4, – Stopcocks used to cut off the water to various parts of the system that are under high pressure.
3 – Draincock – allows the raising main and parts of the system to be drained of water.
5, 6 – Gate valves – isolate water supply to and from water heater
7 – Mains pressure water heater
8 – Inline valves for isolating a washing machine or dish washer.
9 – Overflow pipe from WC system
 

Advantages
  • Less pipe work, smaller or no cistern make it cheaper to install.
  • Drinking water is available at all draw of points.
  • Smaller cistern can be sited below the ceiling.
  • In systems without a cistern there is less risk of water pollution.
 
 

 

Indirect or Storage

All plumbing fittings except the kitchen sink is supplied with cold water via a storage cistern, which can also be used to supply the hot water supply system.

 
Figure_11.2
Figure 11.2.2 Indirect System for Cold Water Supply

Key:
1,2,4, – Stopcocks used to cut off the water to various parts of the system that are under high pressure.
3 – Draincock – allows the raising main and parts of the system to be drained of water.
5 – Cold water storage tank – situated at the highest part in the building it is controlled with a ball valve which allows the tank to be topped up when water is drawn off.
6, 9 – Gate valves – isolate water supply to parts of the system which are fed under low pressure.
8 – Hot water cylinder
10 – Overflow pipe from storage tank to direct any water outside the building.
11 – Overflow pipe from WC system
12 – Inline valves for isolating a washing machine or dish washer.
 
 

High Rise Buildings

For high rise buildings it will be necessary to position storage tanks every few floors and to pump the water from the mains to the tanks, an example of this is shown below. A more detailed explanation is provided in Chapter 2 of the unit book.
 Figure_11
Figure 11.2.3     High Rise System for Cold Water

 

 


Task 11.2.1 Facilities for Water Supply

Produce a line drawing showing the layout of the water facilities for a four storey office building with ladies and gents toilets and a kitchen on each floor.


 

11.2.2 Drainage and Sanitation

For the benefit of peoples’ health and comfort it is necessary to remove all water and waste products from a dwelling in a safe and efficient manner. The method of doing this is done in two stages:
  1. Removing it from the appliance in the building by the use of pipework and depositing it into the drains - known as above ground drainage.
  2. Removing it from the curtilage and taking it by underground pipes to be treated and disposed of – known as below ground drainage.


Systems

The systems that we have to remove waste fall into the following categories:
  • Above Ground Drainage – deals with the system of pipework which carries soil and waste water from the appliances in the building to the below ground drainage.
  • Below Ground Drainage – the pipework which carries soil and waste away from the building to a source of treatment or disposal.
  • Rainwater Drainage – this can be a system which is combined with the soil and waste system or a separate system carrying rainwater away from a property to a safe place for disposal.
 

Above Ground Drainage

The purpose of this is to remove all waste water and soil from the building in a safe and efficient manner. The Approved Document H of the Building Regulations provides details of how this should be done and the precautions that must be taken.

The system consists of pipe work running from each appliance into a central stack with a means of preventing odours from entering the building from the drainage system. The size and material of the pipes will depend on the size of the building, the number of appliances. The system must include the ability to access all parts of the pipe work in order to release any blockages should they occur.

Part 9 of the book listed above provides a general introduction to the requirements.

 

Below Ground Drainage

When the stack pipe carrying the waste and soil from the appliances enters the ground it connects to the drain pipe.  It then becomes known as the below drainage. It is this which will take it from the building and deposit it into the public sewer. Like the above ground system it will be necessary to ensure that all parts of the system are accessible for clearing in the event of a blockage, this can be done through a rodding point or inspection chamber: Part 8 of the recommended book deals with these aspects.

 


Task 11.2.2 Soil and Waste Removal

Produce a line drawing of a typical dwelling showing how the soil and waste is removed from the appliances and deposited into the public sewer. This should show the location of all traps and the means of access to both the above and below drainage system.

 

 
11.2.3 Electrical Lighting and Power


Electricity

Electricity is brought into the dwelling from the supply cable. On entry it goes into the Power company’s fuse which allows the supply to be disconnected by the provider. From there leads are taken to the power companies meter and then to the consumer unit which provides protection to the wiring within the building and enables the power to be switched off by the property owner/occupier.

 

Wiring Circuits

The electricity is carried by the means of cables and is formed into circuits with their own protection (ie fuse, circuit breaker). These are described as either radial or ring.

 
Radial Circuit

This is where power is transmitted from point to point by a single length of cable linking each point to the next. There are a number of options for the wiring which can be a loop-in or junction box system. It runs from the consumer unit and finishes at the last connected device: This system is normally used for lighting.
Figure_11
Figure 11.2.4  Radial Circuit

 

Ring Circuit

A ring circuit (often referred to as a ring main) provides two independent conductors for live, neutral and earth which travel around the building from the consumer unit and connect to each load or socket as seen in the illustration below. The use of the two connectors enables the use of smaller-diameter wire than would be used in a radial circuit.
 
Figure_11.2
Figure 11.2.5 Ring Circuit

 
 


Task 11.2.3 Electricity

With the use of an illustration explain the layout of the electricity provision for a single storey 1 bed roomed dwelling.

 

11.2.4 Heating

Heating Design

A building is made up of a number of components called elements such as walls, roof, floors, windows and doors, etc. These elements enclose the spaces but also help to protect from the cold outside temperatures. These are made of various materials each having different thermal properties. In colder climates, we have to ensure that heat does not escape and is retained within a building. We design and construct the building elements to ensure that these do not loose heat.

Buildings also gain heat from a number of sources such solar radiations, people working inside a building, machinery and equipment.

We can determine how much heat the building is losing and how much it is gaining. The net result will tell us about the heating requirements of a building and the amount of energy required to maintain the building at a comfortable environment for the occupiers.  

 

Factors Affecting the Internal Environment

Many factors affect the internal environment and consequently the amount of heat required to be put into a room to achieve the thermal comfort of the occupants, these are:
  • External Weather Conditions - Consider degree days; heat will pass from a warm material to a cold one, from the warm side of a wall to the cool side.
  • Exposure - cold winds blowing over a building will take heat away, heat loss is affected by air movement.
  • Materials of Construction - type and thickness. Heat will pass through a material according to its thermal conductivity; dense materials conduct heat better than less dense (these being used for insulation ie rockwool, fibre glass).

If insulation is placed on the inside of the building the building will heat up quicker because it will not have to heat up the fabric, just the air. If insulation is on the outside it will take longer as the walls themselves will have to be heated, however, once the heat has been turned off the building with internal insulation will cool down quicker, whereas the heat in the walls of the externally insulated building will radiate heat back into the room. The thicker the walls the greater effect this has, and the longer it takes to heat up, or the heat to work its way through ie. Churches being cool in summer.

 

Solar Gain - the intensity of this can be controlled by the orientation of the building, and the direction, size and shape of the windows. It is not a good idea to reduce their size as this will reduce the levels of illumination.

Heat gain from windows can be reduced by:
  • Internal blinds.
  • External blinds and shades.
  • Recessed windows.
  • Heat reflecting/absorbing glass.
The time of year is also relevant as shades can be used in summer to reduce solar gain but will allow sunshine to enter in winter when the sun is low.

 

Air Changes - as the air changes, either by natural or mechanical ventilation, it removes heat with it. (Building Regulations specifies a minimum number of air changes per hour)

In a balanced system of mechanical ventilation a heat exchange unit is incorporated to use this heat to heat incoming air. Another advantage of mechanical ventilation is that it removes smells and moisture vapour thus reducing condensation and mould growth.

 

Shape and Type of Building - a semi-detached house will lose less heat than a detached, while a terrace will lose even less as it is not exposed on two of its’ sides.

 

Heat Loss

Heat will be lost from a building through the following ways:
  • Draughts
  • Conduction of heat through the building materials
  • Radiation of heat from the building as a whole
  • Convection of heat by the air in contact with the outside of the building.
In order to ensure the comfort of the occupants all heat losses must be allowed for and an appropriate amount of heat put into the building to maintain the temperature at a comfortable level.

 

Heating Requirements

The most important factor in determining the heating requirements of a building is the heat loss which depends upon a number of factors as below:
  • How well the building is insulated externally. The exterior part of a building can be called as a Shell, Fabric or an Envelope.
  • What is the area of the building exposed externally? For example a terraced house is less ‘exposed’ than a detached one and hence will loose less heat.
  • What is the temperature difference between inside and outside of a building? If the difference is large, heat loss will be more, for example, when you open a door or a window.
  • What is the air change rate? Air can move out of a building taking heat with it. This movement can be through cracks and gaps in construction or through opening doors and windows.
  • How a building is used? Whether whole building is occupied all the time or there are different ‘patterns’ for various areas.
 

Heat Loss

As described earlier, the building can lose heat through its external elements or ‘fabric’ as well as through ventilation. Add the two together and you will find the total heat loss from a building.

Fabric heat loss is calculated by considering individual elements and their respective areas. Ventilation heat loss is calculated by considering volume of the room and number of air changes. Both also take into account the temperature difference between inside and outside of a building.

 

Heat Gains

A building gains heat through: solar radiations; internal heat gains; and ventilation and infiltration.

Solar radiations strike the buildings at a certain angle and intensity depending upon the location of the building. This heat is transferred inside through walls, roof and windows.

Solar heat gain can be calculated by using reference tables and computer software.

Internal heat gains are a result of number of a people in the building, what they are doing and what kind of lighting, machinery and equipment is there.

Total heat gain of a building is the sum of all the individual heat gains.

 

Thermal Comfort

The thermal comfort of the occupants is related to the thermal functions of the body, which must be controlled within certain limits depending on the type of use of the building, and the age and activities of the occupants.

The greatest degree of thermal comfort exists when:
  • Air temperature is between 16 - 22oC. Temperature difference between head and feet is no more than 3oC.
  • Surface temperature is at or above air temperature.
  • Air movement is preferably variable between 0.1 and 0.25 m/s, if more draughts are experienced with the angles and necks most venerable.
  • Humidity is between 40 - 60%.
 

Heating Systems

Types of Heating
  • Direct – this is where an appliance provides a source of heating direct to a room ie an electric fan heater.
  • Central – in this case some form of medium i.e. water or air is heated at a centrally located position. The medium is then transmitted around a building where it provides heats to each room, i.e. via a radiator.

Types of Fuel

The means of providing heat can be by:
  • Solid Fuel - coal, coke, biofuel
  • Oil
  • Gas
  • Electricity

Types of Central Heating Systems
  • Hot water circulatory Systems
  • Ducted warm-air Systems
  • Fabric-borne Systems (heated ceiling panels, under floor heating).
 

Hot Water Systems

Water is generally used as it is able to convey more heat per diameter of pipe than any other commonly found media. The higher the temperature of the water the smaller the pipes and the emitters required. When low pressure hot water is used for heating systems the temperature of the water is below boiling point, usually 80oC on the flow.

The water may circulate by either natural convection or by the use of a pump. The pump allows a quicker response time and smaller pipes to be used.

Systems may be open, which requires a feed and expansion cistern, or sealed which uses a flexible membrane expansion vessel.

With the other exception of the different way that is used to allow for the expansion of the water when it becomes hot, the layout of the systems is the same.

Various configurations are available for the layout of the pipe work carrying the water to and from the heat emitters, though these are generally classed as one or two pipe systems.

 

One-pipe System

These require less pipe work and are cheaper to install, although they are not as efficient as the two-pipe system due to all water passing through each radiator, the radiator at the end of the system receives water which is cooler than that received by the first radiator. Also, although the pump forces water round the pipe work it does not force it round the radiator which relies on natural convection.

 
Figure_11.2
Figure 11.2.6  One-pipe System


 
Two-pipe System
 
When water passes through a radiator it is returned directly back to the boiler for re-heating, this ensures a better balance of heat to each emitter. If pumped the water is forced through each emitter.
 
 
Figure_11.2
Figure 11.2.7 Two-piped System


Part 4 of the recommended book deals with this subject in more detail.
 
 


Task 11.2.4 Heating Systems

Look at the main types of heating systems and explain the advantages and disadvantages of each.

Word Guide:  300 – 400

 

 
11.2.5 Gas

Regulations

All work relating to gas must be carried out in compliance to the Gas Safety (installation and use) Regulations 1994. These cover the safe installation, maintenance and use of gas systems and appliances in domestic and commercial premises

The requirements and regulations can be found in Part 10 of the book specified above, it explains the way that gas is brought into a building and the requirements for its safe use.

 
 

 

Section 3.  Specialist Services

Learning outcome: On completion the learner will know some of the specialist services for a building.


 Contents
 
11.3.1 Mechanical Ventilation and Air Conditioning
11.3.2 Fire Prevention Systems
11.3.3 Security Systems
11.3.4 Communication Systems
11.3.5 Transportation Systems
 

 

11.3.1 Mechanical Ventilation and Air Conditioning

Determining Heating, Ventilation and Air Conditioning Requirements

In order to be able to determine the requirements for the heating, ventilation and air conditioning system for a building it is essential that you are aware of the factors listed below as they affect the choices available in determining the system to be employed.
  • The analysis and interpretation of client and building operational requirements,
  • The design standards with regard to these services as they relate to the different types of buildings ie commercial, industrial etc.
  • The balance between clients needs, commercial constraints, health and safety, aesthetic and energy efficiency considerations.
  • Use and effect of natural ventilation.
  • The Inter-relationship between ventilation and air conditioning and other mechanical and electrical building services
  • It is also essential that you know the factors which will affect the requirements. This relates not only to the building and its’ use but also the environment in which it will be situated.

The main factors which will need to be known are:
  • Climate
  • Building envelope
  • Occupancy and Use
 

Climate

The climate and weather conditions will have an effect on the amount of energy that is required in a building in order to maintain a comfortable living/working environment for the occupants.

If the weather is particularly cold there will be a greater need for energy to heat the building, conversely, if there is a heat wave more energy will be required to maintain the air conditioning. Consequently the weather is a major factor in determining the requirements in a building. This will be affected by the location that the building is to be constructed as a building in the Middle East will need more energy to cool the building while one in Norway will require it for heating.

Exposure is also relevant as a building situated in an unprotected location overlooking the North Sea will have a different requirement to one build in the centre of a city.

 

Building Envelope

The design of the services should be integral to that of the building envelope as this has an influence on the energy requirements and also the ability to maintain or repair any system installed in it. The requirements with regard to energy efficiency of the building envelope are specified within EU directives and the Building Regulations. More details with regard to this can be found in the constructionsite unit ‘Sustainable Legislation’ a link to which is provided below.

The building envelope will also have an influence on the amount of heat loss and the thermal properties of the materials used. You must be familiar with the principles involved with this so you should go to the constructionsite unit Thermal Studies a link to which is provided below.

 

Occupancy and Use

The improved quality of thermal properties of buildings due to improved energy regulations is having a reduction in the overall energy use making the role of the occupant more important. Though at the design stage consideration must be given to the occupants as the temperature requirements for a hospital may be greater to maintain a comfortable environment than that for a sports centre. The processes carried out or equipment used in a building will also influence the ventilation requirements and air conditioning.

 

Energy Costs

Considering the above will enable the potential energy costs to be calculated. Further details on this can be obtained from the Building Services Engineering book indicated below.

 

Ventilation and Air Conditioning Systems

Ventilation is the intentional movement of air from outside a building to the inside. The movement of air between indoor spaces, and not the outside, is called transfer air.

When people or animals are present in buildings, ventilation air is necessary to dilute odours and limit the concentration of carbon dioxide and airborne pollutants such as dust, smoke and volatile organic compounds (VOCs). Ventilation air is often delivered to spaces by mechanical systems which may also heat, cool, humidify and dehumidify the space. Air movement into buildings can occur due to uncontrolled infiltration of outside air through the building fabric or the use of deliberate natural ventilation strategies. Advanced air filtration and treatment processes such as scrubbing, can provide ventilation air by cleaning and re-circulating a proportion of the air inside a building.

Air Conditioning is a system or process for controlling the temperature and sometimes the humidity and purity of the air in a building.

 

Evaluating Ventilation and Air Conditioning Systems

There are a number of types of ventilation system that can be selected according to the building and processes that are carried out within it and you will need to understand these and where they are used in order. These can be:
  • Natural - occurs when the air in a space is changed with outdoor air without the use mechanical systems, such as a fan. Most often natural ventilation is assured through operable windows but it can also be achieved through temperature and pressure differences between spaces. Natural ventilation is generally impractical for larger buildings, as they tend to be large, sealed and climate controlled.
  • Mechanical – this occurs through an air handling unit or direct injection to a space by a fan. A local exhaust fan can enhance infiltration or natural ventilation, thus increasing the ventilation air flow rate.
  • Mixed flow - Details of this and Displacement ventilation can be found by visiting the 'Displaced v Mixed Flow Ventilation' at the website below.
  • Displacement ventilation.
  • Combination of ventilation and air conditioning systems – This works on the premise that temperature humidity, air movement and solar intensity define the internal climate of a building and need to be in balance in order to ensure optimum comfort and productivity.
 

Selection

The selection of an air conditioning system will depend on:
  • The relative needs.
  • Sizing and selection of plant, ductwork and pipework,
  • Design implications on space, maintenance and commissioning requirements,
  • Capital and operating costs.
  • Comparisons between centralized and packaged equipment.
 

Air Conditioning

An air conditioning system conditions the air to create a comfortable environment for the occupants of a building. The system does so by cooling the air, keeping it at the right humidity and by ventilation.

To cool the air, we have to remove heat. This is the basic principle an air conditioning system follows. Heat removal is done with the help of a refrigeration cycle.

In this section, we will discuss the characteristics of an air conditioning system.

 

Refrigerants

Refrigeration is required in an air conditioning system. We will discuss how it works. First, consider how your refrigerator at home gets rid of heat. It takes heat from your refrigerator and dissipates it through pipe work at the back.

To understand how this works, consider if by accident you get a little amount of petrol on your skin. After a while, the petrol evaporates and you feel cold on that area because petrol has removed heat from the skin. This is the principle of refrigeration.

Any substance which evaporates quickly, such as petrol, is called volatile. We use a highly volatile liquid in refrigerators to take the heat way. This highly volatile liquid is called a Refrigerant. Common examples are ammonia, methane and carbon dioxide.

 

Evaporator

Consider a system in which we wish to let warm water in and get cold water out. We can do so if we pass a highly volatile liquid in the system which will take the heat from the warm water, we will be able to have cold water out of the system. The liquid after taking the heat will evaporate. Such systems generally fall under the category of Heat Exchangers. The heat exchanger in this example is called an Evaporator.

 

Condenser

In the previous example, we will have to replace the highly volatile liquid each time we require cold water.

To let the cycle run continuously so that no replacement is required, we can condense the vapourised liquid back to the liquid state. In this case, we will let the vapours pass onto something cold so that it is condensed back to liquid. Such a system is called a Condenser.

 

Refrigeration cycle

If we develop a system with a condenser and an evaporator where a refrigerant is passed through the system, we will have a simple and continuous refrigeration cycle. The highly volatile substance or refrigerant is passed through the system by using either a pump or a compressor.

 

Air conditioning systems

If we have one central source of conditioned air and supply it to the whole building through ducts, it is called the central plant system. We can also have systems for individual rooms as well as which can condition the air in that particular space.

We have discussed condensers and evaporators. An air conditioning system keeps the humidity at the correct level. If it is required to add moisture to dry air, a humidifier is used. In UK, humidification is hardly used though it is required in dry regions throughout the year. In tropical climates, the system should be able to remove moisture for which a de-humidifier is used.

In a central plant, Dampers are used to control the amount of air that goes into each duct. Filters are used to trap dust and pollution.

 

Systems

A number of system of air conditioning exist, these are explained in Part 7 of the specified book for this unit. They include Variable Air Volume, Induction systems, Fan-coil unit and the Duel Duct System.

 
 


Task 11.3.1 Air Conditioning

Briefly explain the air conditioning systems that are available.

Word Guide: 300 – 400
 
 
 

11.3.2 Fire Prevention Systems


Fire Fighting

Fire fighting systems are referred to as active systems, examples of these are water sprinkler and spray systems while the measures used to protect materials are known as passive which will generally consists of a coating of fire resistant insulating material applied to the structure. In this unit we will look just at the active systems though explanations of the passive, as well as the active, can be found on the HSE website linked to below.
 

Sprinkler Systems

Sprinkler systems are designed to protect life and/or property and may be regarded as a cost-effective solution for reducing the risks created by fire as they can be very effective in controlling fires. A sprinkler system is usually part of a package of fire precautions in a building and may form an integral part of the fire strategy for the building.

Sprinkler protection could give additional benefits, such as a reduction in the amount of portable fire-fighting equipment necessary, and the relaxation of restrictions in the design of buildings. 


Wet and Dry Risers

Wet and Dry risers are intended for the use of the Fire Service to provide a readily available means of delivering considerable quantities of water.

Dry risers are vertical mains fitted into staircase enclosures or other suitable positions, constructed of 4'' galvanized steel pipe with outlet valves on each floor and an inlet fitted at ground level to enable the fire brigade to connect to the water supply.

Wet risers are pipes kept permanently charged with water either from a storage tank (via a booster pump) or direct from the town's main water supply.

Details of these systems can be found by selecting the website link below.


Foam Inlets

Foam inlets are special inlets usually fitted to provide an efficient way of extinguishing a fire in a basement or other area of high risk such as plant room. In many respects they look the same as rising main inlet boxes, but the door should be clearly marked "foam inlet". The risk area should be kept clear of obstructions to allow the foam to spread into the compartment.
 

Sprinkler Systems

This is a system containing pipe-work which can be filled with water (wet system) with a sprinkler which seals the pipe-work. If the temperature reaches a certain level the glass breaks and release water in the area of the fire. An alternative system is where the pipe-work is not filled with water until the sprinkler bulb is broken which then lets water into the system. 


Fire Alarm

The purpose of a Fire Alarm Systems is to warn people in a building that there may be a fire and that the building should be evacuated. They tend to operate by a detector detecting smoke or heat, or someone operating a break glass unit. It may also incorporate remote signalling equipment which would alert the fire brigade via a central station.
 
Fire Alarm Systems can be broken down into three categories, Conventional, Addressable Analogue Addressable and Wireless systems. Information on these systems can be gained by visiting the Fire Safety Advice Centre page for Fire Alarms below.
 

Fire & Smoke Detection

The majority of people who die in fires are not burnt but are overcome by the smoke and gases. In order to evaluate the risk to people in buildings and to the building itself you will need to understand the way fires grow and how smoke and poisonous gases can spread through a building.

A fire in a building can generate thick, black smoke that can obscures vision, block the escape routes and cause great difficulty in breathing. Smoke is a serious threat to life which should not be underestimated. In this unit we will look at the principles and characteristics of fire and smoke and their dynamics.

 

Fire Detection and Alarm Installations

The design of the installation should be considered at the design stage of the building and not as an afterthought once the building is designed. Consideration needs to be given to the environmental factors but also the way that it integrates into the building. If cables are used then routes need to be planned around the structure, which ensure the best possible routes and protection. Although greater use is being made of wire free systems and you should be aware of the circumstance where these can, and cannot be used.

Buildings contain a wide variety of environments and hazards and some, i.e. hospitals will have a number within the same building; each with their own specific hazards as well as more general considerations.

The term fire detection and alarm systems, in BS 5839, includes systems that range from those comprising only one or two manual call points and sounders to complex networked systems that incorporate a large number of automatic fire detectors, manual call points and sounders, connected to numerous inter-communicating control and indicating panels. The term also includes systems that are capable of providing signals to initiate the operation of other fire protection systems and equipment (such as fire extinguishing systems, smoke control systems or automatic door release equipment) or safety measures (such as shut down of air handling systems, closing of oil or gas valves, or grounding of lifts).

 
 


Task 11.3.2 Fire Prevention

Give an overview of the measures which can be adopted in order to protect a building against fire.

Word Guide: 300 – 400
 

 

11.3.3 Security Systems

Design Considerations

Each project requires an individual approach to assess it in order to provide a suitable solution. Even buildings that appear similar may have different needs because of their occupants and the way they are used, so there is no standard installation although the systems and approaches will be similar.
Prior to the design of a system there is a need to carry out a detailed look at the following factors:
  • Type of building
  • Type of use
  • Hours of use
  • Users
  • Materials and construction
  • Access
  • Threats – perpetrators, type of attack
  • What needs to be protected
The production of a survey will highlight the factors which need to be addressed and then consider the measure which can be introduced to efficiently provide the protection that is needed according to the threats determined.

 

Purpose of Security Systems

The purpose of a security system is to:
 
Deter

In order to do this, aspects will need to be overt where a potential burglar will see that the building has good measures of security. The first line of defence will be the physical measures such as good locks, fences etc. It will also include security lighting and a visual alarm box together with warnings that the building is protected. Although the prospect of them being seen is also a major factor in deterring potential offenders.


Detect

This is done by equipment placed in the building that can detect an intrusion. These can amount to contacts which trigger an alarm if made or broken depending on the system. These tend to be placed at windows, doors or as pressure mats at specific locations.

Sensors which detect heat or movement are also used.

These are connected to a control panel which activates the alarm. Alarms can be audible or silent which will notify a security company or automatically dial 999.

 
Assist with Prosecution

Any evidence obtained through the use of CCTV will assist in the apprehension and prosecution of any person breaching or attempting to breach the security of a building.

 

Security Systems

The purpose of any security system is to raise the alarm in the event of an intruder triggering the system. This may be done locally by sounding of a bell, siren and the use of light either indoors, outdoors or both. Alternatively remote alarm systems are used to connect the sensors via a control panel to a predetermined monitor. It is the sensor which activates the system, these can be:
Internal
  • Passive infra-red detectors
  • Ultrasonic detectors
  • Microwave detectors
  • Photo-electric beams
  • Pressure mats
 
Outdoor
  • Vibration (shaker) or inertia sensor
  • Passive magnetic field detection
  • E-field,
  • Microwave barriers
  • Microphonic systems
  • Taut wire fence systems
  • Fibre optic cable
  • H-field
Various types of security system may be required within the buildings the most likely being one or all of the following:

 

Intruder Alarms

The requirements of an alarm system will depend on the type of building, its use and the likely threat. Consequently, a detailed knowledge is needed of these factors before any specification can be produced. This will entail the analyses of the architectural design and construction of the building and the materials used.

It will also need a detailed analyse of the work procedures and processes used within the building and the dangers that these pose.

A thorough understanding of the types of systems available and their use must be held in order to ensure that the equipment specified is the most appropriate for the situation.

 

Performance Requirements

A specific requirement may be set by the client/specification with regard to not only the installation detection requirements but also the installation itself, these may include:
  • Compliance with regulatory requirements
  • Multi Protocol
  • Modular concept
  • Simple, robust design
  • Intuitive to use
  • Easy to maintain
  • Low cost to maintain & hold spares
  • Easy to expand
  • Easy to install
  • Easy to configure
Intruder alarms will generally comprise a control panel, space detection, alarm contacts external sounder and generally, remote monitoring facilities.

 

CCTV Systems

CCTV systems will generally comprise cameras distributed around the site and wired back to a central manned position where monitoring and recording equipment is installed.

Some more sophisticated systems may have movable cameras with zoom facilities and the ability to record.

The extent of any system will depend on the building and the client requirements.


Intercom Systems

Intercom systems can be provided at the entrances of the premises and installed in conjunction with some form of access control system.


Access Control systems

Selected buildings will require access control. This may be as simple as one controlled door or a complete building system with the associated monitoring and control equipment.
 

Monitoring

The system can be either monitored on site or by central off site monitoring, which will depend on the type of premises to be protected.


Perimeter Systems

These are used to protect the perimeter of an area. The perimeter systems website provides details of the type of systems available.

The security system must be able to act whenever a threat is detected regardless of the circumstance, this means that a back-up system is required to allow the failure of given parts of a system, i.e. if the electricity supply is interrupted then a battery system will automatically take over.
 
 


Task 11.3.3 Security Systems

Discuss the factors you would consider when planning the requirements for security in a building.

Word Guide: 300 – 400
 
 
 

11.3.4 Communication Systems

The advent of communication systems has necessitated the development of systems to allow their use around a building. Where this just involved the inclusion of a switch board and wires to different offices it now includes the cables or devises for computers and internet access. Consequently these need to be considered at the design stage and the ducting planned into the building fabric. 

 

11.3.5 Transportation Systems

This relates to Lifts, Hoists and Escalators. It is now a requirement that people using a building must have access to all parts regardless of any disabilities that they may have.  This therefore requires the installation of lifts to ensure users can access all floors. On larger buildings it is also common to install some form of transporting people around the building. This may be by the use of an escalator or on travelators.

 

Additional Information

Additional information can be found by visiting the constructionsite units accessible from the link at the top of the left hand column.

 
 



Unit Complete
 
You have now completed Unit 11, and you should complete the assignment and send it to info@gatesmacbain.co.uk.

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