MSc02 - LCAM Flashcards
operational energy
energy used to operate the energy (use phase)
embodied energy
- energy used to etablish the building (Process phase)
- Energy embodied in the construction increases
with level of insulation and building service systems
what are the 5 principles for design for disassembly?
- Reusable materials
- Designing with regards to the buildings lifespan
- standartized element
- reversable connections that can be pulled apart and put together repeatadly
- design the building for deconstruction
which considerations would be relevant to make when choosing materials?
- The desired appearance of the building
- The character of the material (sensuous perception)
-** Indoor environmental impact**: materials emissions to indoors - The **technical properties **of the material
- Environmental impact, LCA,
- The processing of the material (format, module, mounting etc.)
- Possible** recycling or reuse**
-
Maintenance
Etc….
what are the the three main main ways of describing the role of materials, according to Beider.
- **technology **(processing)
- material (inherent properties),
- materiality (character: perceiving materials)
what qualities can be assessed with regards to technology?
what qualities can be assessed with regards to material?
what qualities can be assessed with regards to materiality?
what are the three perspectives constituting the architectural object, according to Beider?
-** entity **(Semper‘s hearth, mounding, roofing and walling)
- enclosure (body: elements and surfaces)
- transition (joints)
se L01, p. 3
how do materials relate to context?
different climates offer and needs different materials
climatezones: köppen climate classification world map
what are system boundaries?
- system boundaries define what is being included in the calculation/analysis and what is not
- they affect the result of the analysis
Thermal transmittance
U-value
primary energy
includes energy in construction and building service systems for heating, DHW and electricity
what is the limit value for buildings over 1000m2?
12 kg CO2-eq./m2/year
GWP
Global warming potential
- a buildings potential to affect global warmning, which mirrors it carbon footprint
- The GWP of all gases is calculated in relation to CO2. Therefore, the unit is CO2-equivalent (CO2e)
A1-A3
Product stage
A1 Extraction of raw materials
A2 Transport to production site
A3 Manufacture of the product
this is where especially recycled and reused materials will be reflected
B4
replacements
each element has a assigned service life which depends on application and material
- to be able to compare building projects a reference period of 50 years is used
service life according to BUILD Report 2021:32
How often should a element be replaced if the service life is shorter than 50?
Number of replacements= (50years/service life)−1(rounded to full service life)
How is GWP calculated for B4?
calculated based on the number of replacements and impacts in A1-A3 and C3-C4
GWP of 1 replacement = A1+A2+A3+C3+C4
Products with one replacement have a twice as high impact without one without replacement*
what is not included in b4?
paint of floors, walls and ceilings
B6
operational energy use
B6 is the result of the impacts of the calculated energy demand (electricity and heat) over 50 years of operation:
How is B6 calculated
the energy demand is multiplied by an emission factor for energy production over a 50 year period
What are emission factors? (b6)
factor that indicates the expected climate impact of a specific energy source in DK
- indicating the climate impact of 1 kWh of the selected energy source
C3 - C4
Waste processing (C3) and disposal (C4)
- end of life
- always assumed happens after 50 years
- can be found in datasets or EDP’s
D
Potential reuse, recycling and recovery of resources
The module must not be included the building’s impacts, as the potential belongs to new product systems
Reference area
GWP of materials in A1-3, B4, C3-4 and D will be distributed across the reference area
The reference area is based on the building’s floor area cf. BR18, §455,
what is temperature?
heat, energy, kinetic energy,
what happens when two object with different temperatures touch eachother?
the coolest material will absorb energy from the coldest untill both materials have the same “amout” of energy. likewise, the warmest material will will release energy to the coolest, again, to reach equilibium.
what is contact temperature?
temperature between 2 semi-infinite bodies which are brought in perfect thermal contact
what temperature does one feel when touching things?
contact temperature
is the calculated contact temperature always applicable?
No, Calculation of the contact temperature of two materials in reality is always an estimation as reality is
different from the model assumption: bodies are finite (e.g. a hand or a door handle), the contact is often
not perfect (roughness of the material)
according to L04 exercise, when choosing materialswith regards to temperature, what is important to consider?
calculated contact temperature(statistical), measured contact temprature (actually mesured with themometer), experiencenced contact temperature (physical touch)
what is thermal effusivity, b, and which data is needed to calculate?
a material’s ability to exchange heat with its surrounding and has a time component.
material density, : kg/m³
thermal conductivity, : W/(mK)
specific heat capacity, c: J/(kgK)
(see slide 4 in L04)
How is contact temperature calculated?
T_contact= b1*t” + b2+T2 / b1+b2
b1, T1: thermal effusivity and temperature of material 1
b2, T2: thermal effusivity and temperature of material 2
What does a high thermal effusivity mean?
Materials with a high thermal effusivity are perceived especially cold (hot) when touched when their
temperature is below (above) the skin temperature.
Ideally one would want to choose materials with low thermal effusivity
what effects from buildings’ heat transfer mechanisms are shown in the video in L06?
thermal conductivity
what is Hygric transport
moisture transport
what are some of the hygric transport mechanisms?
diffusion, convection, capillary suction, sorption
what is diffusion
movement of moleculesfrom a region of higher concentration to a region of lower concentration
what is convection
what is capillary suction
absorbtion an destribution of water though mmaterial cells, can turn into free water at the bottom of the construction
what is sorption
the process in which adsorption and absorption take place simultaneously
what is sd?
vapour diffusion-equivalent air layer thickness
how do you determine the vapour resistance of a material?
Z_material = Z_air* sd_material
Z_air= 1,39 * 106 Pam²h/(kg*m)
see L06 slide 9-12
Which questions can a lifecycle assestment answer?
Which material has the least environmental impact for the given purpose in the given context (climate,
location, natural resources, transportation)?
Does it make sense to use even more insulation compared to the savings in operational energy?
How much do building service systems installations (heating, ventilation, automation) contribute to
embodied and operational environmental impacts?
what is a EPD
Provides data on the environmental impact of specific products
EPDs must be third-party verified and comply with standard EN 15804
An EPD is typically valid for 5 years
what is thermal conductivity
Thermal conductivity is defined as the ability of a material to conduct heat from its one side to the other. It is represented with thermal conductivity coefficient λ. Smaller λ indicates that the material has stronger heat insulation and preservation.
Water vapour diffusion resistance factor
- μ (mu),
- represents the resistance of a material to the passage of water vapor through it.
the higher the water vapor diffusion resistance factor, the less permeable the material is to water vapor. This means it’s more effective at preventing the movement of water vapor through it.
what is an sd value
The “sd value” is essentially a measure of the thickness of a material that would produce a specific water vapor resistance under specific conditions. It’s often expressed in meters or millimeters. The higher the sd value, the greater the resistance to water vapor diffusion.
explain vapor pressure
determins where the moidure will go
- This movement happens because water vapor naturally wants to move from areas of higher vapor pressure (inside the house) to areas of lower vapor pressure (outside)
what is the healthy indoor relative humidity?
30% to 50%
what is relative humidity
realtive humidity = the amout of vapor in the air relative to the saturation point
what is vapor pressure
indicates the amount of water/moisture in the air.
when heat increase = vapor increase = higer vapor pressure
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/dvlp/rh.rxml
what are Hygric transport mechanisms
diffusion: movement of molecules from a region of higher concentration to a region of lower
concentration. Diffusion is driven by a gradient in concentration, here: water vapour pressure
convection: transport of vapour with air stream
capillary suction: transport of water through capillars
sorption/desorption : adsorption=adhesion of molecules to a surface and desorption=release of adsorped moisture
both are needed to describe moisture buffering effects
how do you determine vapour resistance of a material
Zmaterial = Z_air‘ * sd_material
Zair‘= 1,39 * 106 Pam²h/(kg*m)
sd_matrial= water vapour diffusion-equivalent air layer thickness,
how does thermal transport work? what is the driving force and flow?
Driving force: temperature difference, Kelvin
Direction of heat flow is from high to low, q, W/m²
how should layers occur with regards to heat protection?
with regards to Thermal resistance: R-values m²K/W,
thermal
resistance of layers shall increase from inside to
outside
How does Water vapour transport occur? driving force and flow direction?
Driving force: Water vapour pressure, Pa difference
Direction of water vapour diffusion flow is from high to low, g, kg/(m²h)
how should layers occur with regard to moisture protection?
Vapour resistance Z, Pa m²h/kg: increases with
sd-values - sd shall decrease from inside to outside to
let vapour go out of the construction
what is sd value?
The water vapour diffusion-equivalent air layer thickness
It is an expression of
resistance to diffusion of water vapour
how is sd value calculated?
sd = thickness of material layer [m] * Mu
Mu= water vapour resistance factor, for air Mu = 1
where to find water vapour resistance factor for materials?
DS EN ISO 10456,
