CVS 467 Building physics and services
1. INTRODUCTION.
1.1. Building physics
Building physics is the science of climate protection in buildings and in built structures to
create a comfortable indoor climate, which can be maintained within specified limits,
regardless of the variations in outdoor climate.
To gain this we need structures that can withstand the external and internal forces of wind,
snow and life loads but also to provide the structures with qualities such as thermal
insulation, air and rain tightness, solar radiation control, sound insulation and biological
protection.
In order to design structures that are energy efficient and healthy to live and work in,
designers have a clear need to balance the heat, air and moisture movement throughout
the building envelope.
a. Heat transfer
In terms of energy performance, managing heat transfer is the most obvious consideration in the
design process. The three basic modes of heat transfer are:
Conduction
Convection
Radiation
b. Air movement
The two basic factors affecting air movement are infiltration (cold air leaking in) and exfiltration
(warm air leaking out). The three phenomena affecting air movement are :
Stack pressure
Wind pressure
Mechanical pressure
The common factor in all these is the presence of holes in the building. This significantly reduces the
energy efficiency of a building and introduces a discrepancy between the as-designed and the as-
built performance of the building, which in turn leads to complex and expensive remedial action.
c. Moisture management
Controlling and managing the moisture movement in a building is fundamental to maintaining the
durability of the building, maximizing energy efficiency, and ensuring the health and safety of the
occupants
In reality, we deal with combined processes, such that a temperature difference generates a
pressure difference, which generates air movement, which in turn may affect the
temperature difference.
Construction materials used ought to serve their purpose in an optimum way, regarding
technical and economical as well as environmental factors. With increased durability and
service life of the construction, the environmental impact per year of use is reduced. Bad
CVS 467 Building physics and services
design of insulated constructions also creates favorable conditions for biological growth
which may endanger indoor air quality and human health and in general have negative
consequences for the indoor environment and comfort.
1.2. Building services
A building should be designed in such a way to provide an environment where people can feel
comfortable, live, work and achieve. Hence, everything inside a building which makes it safe and
comfortable comes under the title “Building services.”
Building services systems are essential provisions for a building, accounting for 20% to 40% of
the total construction cost. Figure 1 shows the cost breakdown of a typical government office
building.
Building service is responsible for the design, installation, and operation and monitoring of the
mechanical, electrical and public health systems required for the safe, comfortable and environmentally
friendly operation of modern buildings.
Building services influence the architecture of a building and play a significant role on the sustainability
and energy demand of a building. Within building services engineering, new roles are emerging, for
example in the areas of renewable energy, sustainability, low carbon technologies and energy
management. With buildings accounting for around 50% of all carbon emissions, building services
engineers play a significant role in combating climate change.
Although those services are indispensable for modern buildings, they also have an impact. In fact the
implementation of those services demands a considerable amount of floor and ceiling so proper
planning is necessary for their allocation. Increase of ceiling and floors will lead to an increase in the cost
CVS 467 Building physics and services
of construction of which the building construction team should be aware. One of the considerable
impacts on buildings is the increase in energy consumption which not only affects the building but the
environment as well.
Main objectives of Building Services Engineering design
Hygiene (prevent disease & ensure health)
Safety (protect against risks)
Comfort (physiological & psychological well-being)
Convenience (efficiency and productivity)
Classification of building services
Buildings should be designed with features to provide better lighting, comfortable space, temperature
and air quality, convenient power and communication capability, high quality sanitation and reliable
systems for the protection of life and property.
Building services are mainly divided into mechanical, electrical and building operation systems.
1. Mechanical systems include:
1- HVAC Systems: heating, ventilation and air conditioning.
2- Site drainage: water drainage, sanitary disposal.
3- Plumbing: water distribution, water treatment, sanitary facilities.
4- Fire protection: water supply, stand pipe, fire and smoke detection, annunciation.
5- Gas supply
2. Electrical systems include:
1- Electrical power: normal, standby, emergency power supply and distribution.
2- Lighting: interior, exterior, emergency light.
3- Auxiliary: telephone, data, audio and video sound
3. Building operation systems include:
CVS 467 Building physics and services
1- Transportation: elevators, escalators, moving walkways.
2- Processing: product, food services.
3- Automation: environmental control and management.
Related areas/disciplines
HVAC+R (heating, ventilating & air-conditioning + refrigeration)
Fire services
Water supply & drainage
Public health
Gas & steam supply
Electrical services
Lighting systems
Security
Facade engineering
Communication
Acoustics
Vertical transportation (e.g. lifts & escalators)
Building management & control system
Refuse disposal system
Some of the roles in the building services industry include:
Service Technicians: Install, maintain, service, repair and troubleshoot HVAC equipment and
other building services using diverse knowledge of electrical components, motors, control
systems, air flow, piping design, thermodynamics and refrigeration systems.
Commissioning Technicians: Carry out the setting up and tuning of new HVAC systems and
complex building services.
Draftspersons: Use sophisticated computer aided design and drawing systems together with
technical knowledge and skills to design and document HVAC and other building services
systems for manufacture and installation.
CVS 467 Building physics and services
Plumbers: Fabricate, install and repair pipe and ductwork systems that carry fluids such as
heating and cooling water and air for air conditioning and ventilation throughout buildings. They
also install the plant and equipment that heats and cools and pumps the fluids and heats and
cools and moves the air.
Engineers: Conceive and design building services systems based on functional requirements and
the need to conserve energy and water, they also play roles in solving problems and ensuring
that systems are maintained correctly and operate efficiently. They address areas such as
thermodynamics, electrical theory, fluid mechanics, mechanical design, materials technology
and regulatory and code compliance.
Sprinkler Fitters: Fabricate, install and repair fire sprinkler and fire hydrant systems that protect
building occupants and buildings from the effects of fire.
Alarms Technicians: Install, maintain service, repair and troubleshoot complex fire and life
safety monitoring and alarm systems that help protect building occupants and buildings from
the effects of fire.
Controls Technicians: Install, maintain service, repair and troubleshoot the sophisticated
computerized building automation systems (BAS) that control the efficient operation of HVAC,
electrical and fire and life safety systems in modern buildings.
Electricians: Install, maintain, service, repair and troubleshoot lighting and power systems.
Contractors and Business Owners: Combines technical and entrepreneurial skills to
communicate and assess customer needs and derive appropriate technical solutions.
