environment

Question 1

1. how is A green or sustainable building deliberately designed?
2. a building lifecyle is the view of a building over the course of its entire life, what are the phases?

Answer 1

1. minimise impact on the natural environment and to maximise efficiency in the use of resources such as materials, water and energy over the lifecycle of the building.
2. Raw materials
   Produced or manufactured products
   Transport from factory to site
   Installation
   Service life and maintenance over lifetime of building
   End of life

Question 2

1. Climate is the set of environmental conditions that surround a building
   - Choice of site for a building follow which general features of a local natural environment?

name design aspects related to human comfort for the following features

2. temperature
3. quality of air
4. acoustic environment
5. lighting environment

Answer 2

1. Availability of drinking water
   Drainage of ground
   Safety from flooding Shelter from prevailing weather
   Appropriate orientation to the Sun
2. Materiality Building insulation
   Building ventilation – systems, façade openings etc., orientation
3. Humidity Ventilation rate
   Air velocity
   temperature
   space activity air pollution
4. Sound insulation/materiality
   functionality, envelope design, allowed noise level
5. functionality, aesthetics, efficiency , sustainability

Question 3

1. what is thermal comfort?
2. 3 ways heat can be transferred?
3. when does heat energy flow out a building?

Answer 3

1. Thermal comfort is defined in British Standard BS EN ISO 7730 as “that condition of mind which expresses satisfaction with the thermal environment. Dissatisfaction can be caused by warm or cool discomfort of the body as a whole
2. conduction, convection, radiation
3. when the temperature inside is higher than the temperature outside.

Question 4

1. what is the u value?
2. resistance formula value formula?
3. u value formula

Answer 4

1. U-value is a measure of the overall rate of heat transfer, by all mechanisms under standard conditions, through a particular section of construction.
2. resistance = d/ upside down y

d=Dimension of layer
Measured in metres

upside down y = thermal conductivity

3. u = 1/ Rse+ Rsi + R1 + R2 … etc

Question 5

1. what is thermal conductivity?
2. what does smaller thermal conductivity indicate?

Answer 5

1. Thermal conductivity is defined as the ability of a material to conduct heat from its one side to the other
2. Smaller λ indicates that the material has stronger heat insulation and preservation.

Question 6

1. conditions for thermal comfort are divided into two categories:
   
   • Factor dependent on environmental conditions
   • Factor dependent on personal preferences
2. name 4 environmental factors
3. name 2 personal factors

Answer 6

1. Air temperature
   Air speed
   Relative humidity
   Radiant temperature
2. Clothing insulation
   Metabolic rate

Question 7

1. what is air temperature?
2. what is surface temperatre?
3. what is radiant asymmetry

Answer 7

1. Air temperature is the average temperature of the air, an occupant is surrounded with.
2. Surface temperature is a measure of the average temperature of the surfaces that surround a particular point.
3. Radiant asymmetry (∆t pr generally for 4.2 K) can also cause discomfort. People are most sensitive to radiant asymmetry caused by warm ceilings or cool walls (windows). (surfaces different temperatures

Question 8

1. 4 environmental factors that affect thermal comfort?
2. 2 personal factors?

Answer 8

1. air speed, (still or stagnant air can lead to it feeling stuffy, moving air in warm conditions can increase heat loss through convection without any change in air temperature, althoiugh small air movements in colder places may be percieved as draughty)

relative humidity (is the amount of water air can hold at a certain temperature.)

Air temperature

Radiant temperature (surface temperature)

2. Clothing insulation
   Metabolic rate (includes activity levels - more activity more heat)

Question 9

1. 7 reasons to ventilate?
2. what should indoor c02 concentrations be?

Answer 9

1. Provide fresh air for respiration

Preserve the correct level of oxygen

Control carbon dioxide content

Control moisture;

Remove excess heat

Dispose of odours, smoke, dust and other atmospheric contaminants.

Relieve stagnation and provide a sense of freshness;

2. CO2 levels indoors should be as close to 400 ppm (outdoor CO2 concentration) as possible.
   However, as a rule of thumb, a maximum CO2 level between 1,000 ppm and 1,100 ppm indoors is a good goal for any

Question 10

1. 3 ways a dwelling can have ventilation?
2. an advantage of Mechanical ventilation with heat recovery (MVHR))?

Answer 10

1. Natural means (Intermittent extract ventilation, Passive stack ventilation (PSV))

Mechanical means (Centralised mechanical extract ventilation (cMEV), Single room heat recovery ventilators (SRHRVs), Mechanical ventilation with heat recovery (MVHR))

Combination of natural and mechanical means (Decentralised mechanical extract ventilation (dMEV)

2. Heat recovery efficiency is up to 85%, so MVHR significantly reduces the ventilation heat loss of a dwelling.

Question 11

1. what are Luminous intensity (I) Luminous Flux: Illuminance: Luminance:

Answer 11

1. Luminous intensity (I) is the power of a light source to emit light in a particular direction. Unit: candela (cd).

Luminous Flux: total light emitted by a source, in lumens (lm)

Illuminance: amount of light falling on a surface, in lux (lx).

Luminance: brightness of a surface as perceived by the eye, in candela per square meter (cd/m²).

Question 12

1. what is Luminance candela per square metere?
2. One method of changing the direction of light is by the process of reflection, what are the two types of reflection?

Answer 12

1. This is the amount of light reflecting off of a surface into a viewers eye. It is used the baseline metric used for assessing glare is luminance within a person’s field of view
2. specular reflection.
   Reflectionis when light bounces off an object. If the surface is smooth and shiny, like glass, water or polishedmetal, the light will reflect at the same angle as it hit the surface. This is calledspecular reflection.

Diffuse reflectionis when light hits an object and reflects in lots of different directions. This happens when the surface is rough. Most of the things we see are because light from a source has reflected off it.

Question 13

1. what is the reflection factor or reflectance?
2. Passive daylighting strategies promote the quantity and even distribution of daylight throughout a building by collecting natural light and reflecting it into darker areas of the building.
   name 2 passive daylight strategies

Answer 13

1. Reflectance is the ratio of the luminous flux reflected from a surface to the flux incident upon the surface.
2. For instance, Alight shelfis apassivearchitecturaldevice used to reflectnatural daylightinto abuilding. ‘Bouncing’ sunlight off a horizontal surface distributesitmore evenly and deeply within aspace, whereas direct sunlight can causeglarenear an opening, whilst leaving darkareasfurther in.

Light wall colors.Light, reflective paint helps light to bounce around the room and makes the space feel brighter.

Question 14

1. what is glare?
2. prevailing approach for dealing with glare/things to consider?

Answer 14

1. Glare is the discomfort or impairment of vision caused by an excessive range of brightness in the visual field
2. the glare source luminance, size, positions of glare sources, overall background luminance

Question 15

1. 9 reasons why lighting is important?

Answer 15

1. Health and Well-being: (Eye Strain Reduction, Circadian Rhythm Maintenance)
   Psychological Impact:(Mood and Morale, Stress Reduction)
   Productivity and Performance: (Concentration and Efficiency, Motivation)
   Accident Prevention:
   Aesthetic Quality:
   Energy Efficiency and Sustainability:
   Economic Implications:(Operating Costs, Property Value)
   Legislation (Health and safety, Energy efficiency, Emergency lighting)
   Accreditations and assessments (BREEAM, LEED)

Question 16

1. 3 main types of artificial light?
2. main advantage of led?

Answer 16

1. incandescent sources,
   (An Incandescent Light Bulb )

gas discharge sources,
(The fluorescent lamps (both long tubes as well as compact lamps – CFLs) are a type of Gas Discharge Lamps)

and semiconductor sources.
(LED stands for Light-Emitting Diode, an electronic device made of two types ofsemiconductor material.

2. The main advantage of LEDs is its Luminous Efficiency or Lumens per Watts ratio. It describes the number of watts a light source consumes to produce a certain lumen of light. Of the three light bulbs mentioned here, LEDs have the best lumen per watt figures.

Question 17

1. 5 ways you can control lighting?
2. 8 qualities to consider lighting criteria?

Answer 17

1. Timer control
   Daylight control
   Occupation control
   Local switching
   Dimmer
2. Light quantity (depends upon the nature of the task )
   Natural light
   Colour quality (specified by illuminance level in lux)
   Glare (depends upon the brightness and contrast of light sources – specified by glare index)
   Directional quality (depends upon the three-dimensional effect required – specified by vector and scalar luminance)
   Energy use (depends on the electrical efficiency of lamps)
   Costs
   Physical properties: include size, appearance and durability of fittings.

Question 18

1. 5 factors affecting natural lighting?
2. where should direct sunlight generally be avoided?

Answer 18

1. The nature and brightness of the sky
   The size, shape and position of the windows.
   Orientation
   Reflections from surfaces inside the room
   Reflections and obstructions from objects outside the room.
2. Direct sunlight should generally be avoided inside working buildings because it can easily cause unacceptable glare.

Question 19

1. Shading for glare control is usually provided internally, using roller blinds or Venetian blinds. However, it may also be external, incorporated within a double skin façade, or integral to the window (as in the case of inter-pane blinds). Most commonly, shades are manually controlled,
   what is one of the main disadvantages of manual shades?

Answer 19

1. well known phenomenon known as ‘blinds down, lights on’, whereby occupants close shades to deal with a glare condition, but do not open them again once that condition has passed. As a result, blinds are often left closed for long periods, meaning that occupants lose the benefits of both daylight exposure and view through the glazing, and that electric lighting energy use is increased.

Question 20

1. another need to control daylight?
2. what is daylight factor?

Answer 20

1. overheating daylight
2. Daylight Factor is the ratio between the actual illuminance at a point inside a room and the illuminance possible from an unobstructed hemisphere of the same sky,

Question 21

1. name daylighting solutions
2. why is combined lighting (daylight and artifical) important?

Answer 21

1. • Windows,
   • rooflights and other building elements
     -clerestory, or narrow strip of windows high up on the wall
     -Modern use of north light in an office environment
2. This system of combined lighting requires careful design so as to preserve the effect of daylight as much as possible, and to make the best use of energy.

The integration of daylighting with electric lighting is particularly suitable in deep rooms and provides greater freedom of planning by reducing the dependence on windows for ordinary working illumination

Question 22

1. what is acoustic comfort?
2. 5 general requirements for good acoustics?

Answer 22

1. absence of unwanted sound and opportunities for acoustic activities without annoying other people
2. adequate levels of sound
   even distribution to all listeners in the room
   rate of decay (reverberation time) suitable for the type of room
   background noise and external noise reduced to acceptable levels
   absence of echoes and similar acoustic defects.

Question 23

1. what can The behaviour of sound paths inside an enclosed space can be affected by the mechanisms of?
2. whatis final acoustic result dependant on?
3. Reflecting surfaces in a room are used to help the even distribution of sound and to increase the overall sound levels by reinforcement of the sound waves.
   what are Unwanted reflections of sound called?

Answer 23

1. reflection,
   - absorption,
   - transmission and
   - diffraction (edges of objects)
2. the particular size and shape of the enclosure,
   the nature of the materials used for the surfaces.
3. echoes ( An echo is a delayed reflection and is strong then causes blurring and confusion of the original sound. )

Question 24

1. Late reflections (echoes) can be minimised by the use of?
2. another factor that can affect acoustics?
3. what is sound absorption?

Answer 24

1. absorbers on those surfaces that cause the echoes (materials
2. hall shape
3. reduction in the sound energy reflected from a surface.

Question 25

1. what does the effective absorption of a surface depend on?

Answer 25

1. the absorption coefficient of the surface material the area of that surface exposed to the sound (total absorption is obtained by multiplying them together)

Question 26

1. what is noise? 2. 3 external factors of acceptance of noise?

Answer 26

1. unwanted or disruptive sound - negatively impacts the acoustic comfort of a space.  2. Type of environment: the type of activity: Frequency structure: different noises contain different frequencies. Duration: a short period of high-level noise is less likely to annoy than a long period. Such short exposure causes less damage to hearing

Question 27

1. 3 areas of noise that can cause concern in buildings?

Answer 27

1. Source: can be outside eg road, or inside eg occupants Path: the sound path may be through the air from the source to the building, or the path may be within the building. Receiver: the receiver of the sound may be the building itself, it may be a particular room, or it may be the person hearing the noise.

Question 28

1. other factors that can also affect/be used to control noise levels? 2. 2 main types of sound transferred into buildings?

Answer 28

1. design of quieter vehicles and machinery, location of industry and transport, type of construction 2. Impact sound: is sound generated on a partition Typical sources: footsteps, doors & windows, switches, boilers, noisy pipes, and vibrating machinery Airborne sound: travels through the air before reaching a partition Typical sources: voices, radios, musical instruments, traffic, and aircraft noise

Question 29

1. what is sound insulation? 2. what does The overall sound insulation of a structure depend on? 3. what does insulation vary with?

Answer 29

1. reduction of sound energy transmitted into an adjoining air space (Insulation is the principal method of controlling both airborne sound and impact sound in buildings.) 2. its performance in reducing the airborne and impact sound transferred by all sound paths, direct and indirect 3. frequency

Question 30

1. what 4 things does good sound insulation depend upon? 2. do Heavyweight structures with high mass transmit more or less sound energy than lightweight structures? 3. why?

Answer 30

1. Heaviness Completeness Flexibility Isolation 2. less 3. high density of heavyweight materials restricts the size of the sound vibrations inside the material The final face of the structure, vibrates less than for a lightweight material

Question 31

1. completedness - Areas of reduced insulation or small gaps in the construction of a wall affect overall insulation, what does completeness of a structure depend upon?

Answer 31

1. airtightness and uniformity.

Question 32

1. explain the importance of airtightness on insulation?

Answer 32

1. Some materials porous enough to pass sound through small holes in their structure; brick and blockwork should therefore be plastered or sealed Air gaps often exist because of poorly constructed seals around partitions, particularly at the joins with floors, ceilings, windows, doors, service pipes, and ducts.

Question 33

1. Stiffness is a physical property of a partition; what 2 factors does it depend upon? 1. what is the principle behind the effectiveness of air cavities in windows, floating floors, carpets etc.?

Answer 33

1. the elasticity of the materials the fixing of the partition 2. discontinuous construction sound energy lost at the junction of different materials, insulation is gained.

Question 34

1. which parts of buildings, are regulations typically used to ensure suitable standards of sound insulation?

Answer 34

1. Building envelope: such as the roof, external walls and windows which separate a dwelling from external sources such as noise from industry, road traffic, trains and aircraft. Separating walls: between dwellings and within the same dwelling. Separating floors: between dwellings.

Question 35

1. 4 sound components of walls

Answer 35

1. Heavyweight walls high levels of airborne sound insulation Cavities can increase sound insulation Lightweight walls adequate levels of airborne sound insulation mass through multiple layers of dense plasterboard increases insulation of the wall

Question 36

1. 5 sound components of floors

Answer 36

1. mass of concrete floors provides insulation against airborne sound, but can transfer impact sound a resilient layer also needed to provide insulation against impact sound. methods mass enhancement e.g thick layers of composite floorboard or multiple layers of plasterboard. The insulation of a floor must be maintained at all junctions. The separation of the two parts of a floating floor must continue around all the edges - through use of resilient materials and airtight techniques.

Question 37

1. 6 sound components of windows

Answer 37

1. Glass has a high density increasing the thickness glass - improved sound insulation. Air cavities can increase sound insulation cavity should be lined with absorbent material - minimise resonance two frames must be isolated from one another, through construction technique such e.g resilient layer. the windows shut with a good seal to provide airtightness.