Thermal Performance of Opaque Facade Elements

Question 1

Energy Balance of a building

Answer 1

Is a systematic accounting of all energy flows
- Including all heat gains and losses in a building “System”

Question 2

3 Heat Flows for a buildings energy Balance

Answer 2

1. Heat (Thermal) Demand
2. Heat Storage
3. Heat Loss/gain

Question 3

Heat (Thermal Demand)

Answer 3

Heat supplied or removed by HVAC equipment

Question 4

Heat Storage

Answer 4

Building Heat Capacity

Question 5

What contributes to Heat Gain in a building?

Answer 5

Solar radiation
People
Equipment
Lights

Question 6

Heat gain and loss mechanisms

Answer 6

Conduction/Convection. Walls, roofs, Glazing
Conduction. Ground
Air exchange

Question 7

Define Building envelope

Answer 7

The part of the building that physically separates the exterior environment for the interior environment

Question 8

Building envelope compentents

Answer 8

Walls
Roof
Windows and door
Floor

Question 9

3 Design features affecting energy Performance

Answer 9

Architecture
Thermal Performance of opaque elements
Thermal Performance of Transparent Building Elements

Question 10

Architecture

Answer 10

Orientation
Geometric Proportions

Question 11

Things that change the Thermal Performance of opaque (Not see through) elements

Answer 11

Insulation Materials
Thermal Bridges
Thermal Mass
Reflectance of exterior Materials
Air leakage

Question 12

Thermal Performance of transparent building elements

Answer 12

Windows
Sun shading
Air leakage

Question 13

Orientation

Answer 13

Maximise south and north façade exposure for daylight harvesting
Minimise western exposure as its hard to shade from the sun

Question 14

Benefits of good orientation

Answer 14

Lower lighting costs
reduce heating loads
Natural ventilation Benefit

Question 15

Thermal properties of opaque materials that determine thermal behaviour of the building envelope

Answer 15

Conductivity
Specific Heat
Thickness
Density

Question 15

Exposed material Properties

Answer 15

Roughness
Thermal Absorbance
Solar Absorbance
Surface Reflectance

Question 16

Surface reflectance and different climates

Answer 16

cold = Dark colours to absorb heat
Warm = Light colours in order to reflect the light.

Question 17

To reduce heat transfer by conduction, an insulation material should:-

Answer 17

Less solid material in comparison to void
The slod material should consist of thin connecting walls or discontinuous fibres

Question 18

To reduce heat transfer by convection, an insulation material should:-

Answer 18

Contain small voids or air pockets within which air movement is minimised

Question 19

Reflective foils

Answer 19

Restrict the absorption and emission of radiant heat energy
Doubles as an air and vapour control barrier

Question 20

Super Insulation Materials means that a material will have

Answer 20

Long term performance of insulating materials in building components and systems

Question 21

Thermal bridges

Answer 21

• Full or partial penetration of the building envelope by materials with a different thermal conductivity
• A change in thickness of the fabric
• A difference between internal and external areas, such as occur at wall/floor/ceiling junctions

Question 22

Negative impacts of thermal bridges

Answer 22

Condensation of vapour and mould development
Deterioration of building elemants
Interstitial Condensation
Deterioration of internal air quality
Heat/Energy Loss