MSc01 - AGB

Question 1

Passive strategies for the warm season

Answer 1

Natural ventilation
External heat gain control
Internal gain control
Bufferzones (thermal mass, building heat capacity):
Evaporative cooling
Building envelope

Question 2

what is the different types of natural ventilation principles and how are they possible?

Answer 2

Cross ventilation - two openings : W < 5H

One sided ventilation - single opening: W < 2H
Double opening: W < 2*5 H

boyance effect - three openings

combined cross and boyance

Question 3

what are the driving forces (physics) of natural ventilation?

Answer 3

wind pressure difference across openings - the wind create wind pressure difference accross building which creates flow

boyance effect/air density - hot air is lighter than cold air

Question 4

What are the parameters of air exchange rate?

Answer 4

window effective opening area
window size
pressure differences

Question 5

what are the advantages of natural ventilation?

Answer 5

+ No fan, no pipe-work
+ Low energy consumption
+ Large occupant impact and well received by occupants
+ Both ventilation and passive cooling
+ Integrated with the building and can be combined with
other passive energy technologies

Question 6

what re the disadvantages of natural ventilation

Answer 6

• Natural driving forces not constant or stable
• Limitation with building layout
• Outdoor dust and traffic noise
• Thermal discomfort in winter
• Highly depend on occupant’s control
• Temperature fluctuation

Question 7

What are the possibilites of ventilation during winter??

Answer 7

mechanical ventilation to get rid of excess heat loads and contaminant air

little openings for natural ventilation that minimizes heat loss

Question 8

parameters of cooling residental buildings

Answer 8

Cooling in residential buildings is more correlated to solar
radiation than to outdoor temperatures
* Essential to combine solar shading and ventilative cooling
* Can be needed all year, different solutions required for
different seasons
* Mechanical ventilation flow rates to small to be effective
during summer
* Often required when home is not in use or during night,
automatic control often beneficial and openings protected
against rain, leaves, burglary required

Question 9

how should the ventilation strategies be during different seasons?

Answer 9

Vinter:
Ensidet ventilation

Forår/efterår:
Tværventilation

Sommer:
Kombination af opdriftsog
tværventilation

Question 10

how are Internal gain controlled?

Answer 10

placing appliances outside of occupation areas, zoning,

Question 11

how are External heat gain controlled?

Answer 11

solar transmission/ radiation control
window parameters
building orientation
shading

Question 12

how is a bufferzone created? (thermal mass, building heat capacity):

Answer 12

by thermal mass and using building materials with high heat capacity

Question 13

What is the main issue in warm seasons?

Answer 13

overheating in rooms, especially rooms facing south, west, east

Question 14

Passive strategies for the warm season

Answer 14

passive solar gain
Better building evelope
Sunspace

Question 15

what is the main issue during the warm season?

Answer 15

High energy consumption for heating, high transmission losses in envelope and piping

Question 16

what are the passive strategies for cold season?

Answer 16

passive solar gain
reducing infiltration
Sunspace / heating conductivity
thermal mass

Question 17

What is passive heating and what are important factors?

Answer 17

passive heating is using solar gain and solar incidence to heat up a building. the efficiency of this strategy is determained by the effective solar transmissionarea which is determained by window glazing area, g-value and orientation of windows

Question 18

what is infiltration and how is it reduced?

Answer 18

infiltration is heatloss though the building envelope
reduced by high insulation of the building envelope (air tight)

Question 19

How is thermal mass used during cold season?

Answer 19

by using interior materials with high heat capacity to store heat though radiation

Question 20

How is thermal mass used during warmseason?

Answer 20

by using facade materials with high heat capacity to store heat and delay the heat transfer from outside to inside

Question 21

what is the main issue with regards to natural ventilation:

Answer 21

south facing rooms are overheating, mechanical ventilation is energy-consuming, you need windows towards south to ensure passive heating during winter, in Denmark you need openings towards south and west bc wind = overheating

Question 22

What i Be18 used for?

Answer 22

Energy steady statecalculations

Question 23

what are the advantages of Be18?

Answer 23

Simple, it calculates the energy need according to regulations

Question 24

What are the disadvantages of Be18?

Answer 24

it calculates energy use for the whole building which might not make sense for apartments
doesn’t consider variations in use, enviourment, occupants, seasons, building layout etc.
Considers the upper boundary for energy need

Question 25

What are the advantages of Bsim?

Answer 25

dynamic simulations that takes different parameters into consideration and it gives hourly results

Question 26

what are the disadvantages of Bsim?

Answer 26

the data you give is very precise however, nothing is so predictable
the weather data is from past years

Question 27

how do you design for indoor environmental behavior options?

Answer 27

make things flexible

Question 28

what is human adaptability and what are the main point of adaptive opportunities?

Answer 28

people adapt to the climate they live in and can be an active part of the building operation. this affords autonomy over enviourments

Question 29

what does a window afford?

Answer 29

connection to outdoors
view
fresh air
natural light
regulation of circadian rythms
sense of time

Question 30

what is the role of window openings in a home?

Question 31

how does the design adress seasonally changing weather and climate, changing occupant needs and climate change challenges

Answer 31

by allowing for flexibility and autonomy for the occupants to interact with their environment and regulate it according to their needs.

neither the weather or people are predictable so…