TEQ

Question 1

List at least six key properties of a sustainable building

Answer 1

GPT:
1 Provide specified functions and services with high quality and reliability
2 Provide healthy and comfortable indoor enviroments and minimize the exposure
to toxic materials
3 Have a low life-cycle enviromentalö footprint (Less C02, no impact on flora,
fauna etc.)
4 Are constructed in a way such as to minimize embodied energy and resource
depletion, and conserve non-renewable energy and rare materials.
5 Have an aesthetically pleasing external/internal shape and design/layout
meet required social needs and criteria
6 Operate at an overall cost considered attractive/acceptable to all stakeholders
involved, and have a high real estate value

Question 2

Describe the key benefits of a sustainable building

Answer 2

Lower life-cycle resource consumption (water, energy) and related emissions, and lower impact on local communities

Lower operating and maintenance costs and related overheads – greater profitability

Greater real estate value

Better indoor thermal climate and air quality

Increased occupant comfort, health and satisfaction (residential)

Increased worker productivity, and decreased absenteeism (commercial)

Better (e.g. corporate) image/profile

Deferred investments (e.g. for power generation)

Access to economic/market incentives (tax credits, rebates, low-interest loans and other financial support mechanisms)

Question 3

For what key applications do we need energy in buildings?

Answer 3

GPT: Energy in buildings is needed for heating, cooling, lighting, appliances, ventilation, and various electrical and mechanical systems.

• Thermal comfort control, energy for controlling heating, cooling and the thermal balance (radiation, transmission etc.)
• Indoor air quality management, to achieve that we need energy to control ventilation, filtration, air handling.
• Hygenic requirements, domestic hot water and sanitation (Toilet)
• Energy distribution
• Building operation and control, activites to operate, manage and maintain buildings.
• Transport systems (Elevators, lifts etc)
• Electric appliances and equipment, such as central vacuum systems, kitchens,
  TV, laudries and pools

Question 4

Describe the key categories of heat gains and losses in a building.

Answer 4

Heat gains
- Internal heat gain (Electric suppliances such as TV, kitchen, lamps, people etc)

• Solar heat gain from radiation
• heating from systems

Heat losses
- Transmissions through windows

• Transmissions through facade
• Transmissions through ground floor
• Thermal bridges
• Ventilation and infiltration loss

Question 5

What is a smart building?

Answer 5

A smart building is not a building with high standards at the moment which is
constant. Smart is when the building adaptively responds to changing conditions
to achieve a good indoor climate and promote health, well-being and productivity of its occupant.

Question 6

What is a data-driven smart building?

Answer 6

GPT: A data-driven smart building utilizes sensors and data analytics to make informed decisions and optimize building performance.

EXTRA:
A smart building uses connectivity, software, and data to enable efficient operations and economical use of resources, while creating a safe and
comfortable environment for occupants. Smart buildings may use a mix of a wide range of existing technologies, Internet of Things (IoT) devices, building
management systems (BMS), analytics, and artificial intelligence (AI).

Can include continous data quality validation and assurance

A data structure that facilitates storage and analysis in the cloud.

Automated dispatch of digital commands from cloud-hosted data analytics and/or human decision processes over a suitable “digital platform” interface

Extraction of useful information from the data in order to inform control processes in the building.

Question 7

Describe the purpose of sustainable building technologies and systems

Answer 7

They provide smart, useradapted, comfortable and productive indoor enviroments with high energy and resource efficency, high cost-efficency, high user/customer satisfaction and value, and smallest possible enviromental impact.

• Give a comfortable and productive indoor enviroment
• High energy and recource efficency
• High cost efficency
• High user/customer satisfaction and value
• Smallest possible enviromental impact

Question 8

How does ASHRAE describe human thermal comfort?

Answer 8

GPT: ASHRAE describes human thermal comfort as the state of mind that expresses satisfaction with the thermal environment.

Question 9

Describe the key parameters that define human thermal comfort

Answer 9

Thermal comfort is defined by these components:

• Air temperature
• Radiant temperature
• Air movement
• Relative humidity
• Metabolism
• Insulation
• Air temperature
• Relative Air Humiditity
• Metabolism rate (MET) (activity rate), how much movement? Are the occupant sitting, standing, walking or running?
• Clo value, how much cloths does the occupant have?
• Air velocity
• Mean radianty temperature

Question 10

Explain the terms “Met” and “Clo” in the context of human thermal comfort. Which units are
met and clo expressed in?

Answer 10

MET stands for metabolic rate and describes the activity level, causing internal heat gain.

1 MET= one person sitting still on a chair = 58W/mˆ2
(The energy generated from the human body)

Clo stands for clothing isulation /thermal insulation unit. It’s describing the amount of clothing the occupant is wearing and impacts the heat transport to
and from the body.

1 CLO = “full suit”, pants, shirt and jacket = 0,155K*mˆ2/W

Question 11

Explain the terms “air temperature”, “mean radiant temperature”, “operative temperature”
and “equivalent temperature”

Answer 11

Air temperature T(a) - The average temperature of the air around us. In an indoor setting, this means that the air volume in a room is considered “well mixed” = that the same conditions are valid at every point in the air volume.
(Temperature of the air sourrounding the occupant).

Mean radiant temperature T(r) - is another term, it describes the average temperature of the sourrounding surfaces, taking into account their view factors.
view factors - how well another surface can see another surface will affect how much radiative heat flux which leaves the object.

Operative temperature T(o) - The mean value of the air temperature and the mean radiant temperature. It’s derived
from air temperature, mean radiant temperature and air speed.

Equivalent temperature T(eq) - A concept that include air temperature, mean
radiant temperature, clothing, activity and air velocity.

Question 12

Explain the terms “Actual Mean Vote (AMV)”, “Predicted Mean Vote (PMV)”, “Actual Percent
Dissatisfied APV)” and “Predicted Percent Dissatisfied (PPD)”

Answer 12

Actual Mean Vote (AMV) - How real people assess the thermal comfort at a specific point in time and place, this is a measurement on a scale from -3 to 3, where -3 the person think it is cold and +3 is hot.

Actual Percentage Dissatisfied (APD) - How many persons in the room are dissatisfied with the thermal comfort at a specific point and place regarding if they think it’s too hot or too cold.

Predicted Mean Vote (PMV) - A prediction of the perceived occupant thermal comfort in a room based on a calculation including the factors as air
temperature, mean radiant temperature, relative humidity, air velocity, metabolic rate and the clothing factor. The scale is based on the AMV and you
get a result between -3 to +3.

Predicted Percentage Dissatisfied (PPD) - The percentage of the occupants in a room would be dissatisfied with the thermal comfort, either thinking it is too
cold or too warm.

We can’t expect thermal comfort in every point in a room, only in a defined space which is called occupied zone. Specific in sweden it’s limited between to horizontal lines, one line 0,1m above the floor and the second one 2,0m above the floor. It’s also limited from 0,6m from exterior walls and 1,0m from windows
and exterior doors.

Question 13

Describe the term “occupied zone” using a simple sketch

Answer 13

In Sweden:
0,1-2,0 meter height, 0,6 meter from external wall and 1,0 meter from window

Question 14

Explain (using a graph) the relationship between Predicted Percent Dissatisfied (PPD) and
Predicted Mean Vote (PMV). What is the lowest achievable PPD-value and why can lower
PPD-levels not be achieved?

Answer 14

the PPD can never be 0 because of individual differences in the thermal comfort perception, with different words, people don’t think exactly the same. People can have different thermal comfort perception because of:

Deviation in metabolic rate at equal levels of activity

Different in body surface/volume ratio

Healt - genreal fitness, disease, stress, tiredness

Gender

Age

Acclimatization

Expectations!

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Question 15

How does the International Society of Indoor Air Quality and Climate (ISIAQ) define the term
“Indoor Air Quality (IAQ)”, and how does the American Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE) define the term “Acceptable Indoor Air Quality (IAQ)?

Answer 15

IAQ - An idicator of the types and amounts of pollutants in the air that might cause discomfort or risk of adverse effects on human or animal health, or damage to vegetation.” (ISIAQ)

They discuss a indicator of types and the amount of pollutants.

Acceptable IAQ - “air in which there are no harmful concentrations of contaminants as determined by cognizant (having knowledge or awerness)
authorites and with which 80% or more the exposed occupant do not express dissatisfaction (ASHRAE).

They discuss air which have been proven by cognizant authorites and where at least 80% does not feel/express dissatisfaction.

Question 16

Provide at least four examples of indoor air pollutants. List their sources and (potential)
health effects

Answer 16

VOCs (Formaldehyde) (from building materials and furnishings) - Eyes and mucous membrane irritation

CO2 (from occupants) - Dizziness

Radon (from the ground) - Lung cancer

Particulate matter, PM (from various sources) - Lung diseases and cancer

Question 17

How can poor indoor air quality impact users/occupants in indoor environments?

Answer 17

GPT: Poor indoor air quality can lead to health issues, including respiratory problems, allergies, fatigue, and decreased productivity for building occupants.

(Sick building syndrome: headache
Drowsiness
Eye irritation
Nose and throat infection etc.)

Question 18

Provide at least three examples of services provided by building control systems

Answer 18

GPT: Building control systems provide services like HVAC control, lighting control, security and access control, energy management, and building automation.

• Safety ( indicate hazard, air quality)
• Security (Unautharized acess)
• Comfort (thermal and visual)

Three components in a control system:

Sensors (input, maybe meusering temperature and amount of daylight)

Controllers (reacting to the input and send a message to the controlled device if
it should react or not).

Controlled devices (output, what the system is supposes to do with the respons, give heat och cold air for example)

Question 19

What are the characteristics of an efficient system according to classic control theory?

Answer 19

GPT: An efficient system, according to classic control theory, should be stable, provide a fast response, and have minimal overshoot and oscillation.

An efficient and ideal control system is one that drives the controlled variable to
the desired state (reaches set point with little or no offset), does so in as short a settling time as possible, with as little overshoot as possible and in the most efficient/optimal way as possible.

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Question 20

Name at least five obstacles to designing an efficient control system

Answer 20

GPT: Obstacles to designing an efficient control system include system complexity, uncertainty, sensor limitations, control algorithm design, and cost constraints.

System time lags
- Transfer lag (the time it take to respond from the input)

• Transport lag (respond to output)

Sensor
- location
- bias
- drift
- uncertainty
- Time constant
- Hysteresis

Question 21

How are the terms “state” and “state space” defined by Modern Control Theory?

Answer 21

GPT: state” represents the current condition of the system, and the “state space” is the set of all possible states.

State - it refers to a snapshot in time of a system describing its behaviour with a minimum set of variables

State space - describes all the possible states that a system can attain

Question 22

List and describe the key issues that Modern Control Theory concerns itself with.

Answer 22

GPT: Modern Control Theory concerns itself with stability, controllability, observability, and optimization of control systems.

EXTRA:

Observability: How well internal states of a system can be inferred from knowledge of its external output It means that using the sensor data we collect (output) we can describe our dynamical system with satisfactory accuracy (predict future states)

Controllability: ability of external input to move the internal state of a system from any initial state to any other state in a finite time interval. It means given a specific external input we can push/drive the system to any desired state within our state-space.

Stability: Describes the ability to maintain a reached state
means once we reached a desired state in our state-space we are able to maintain that state over a prolonged period of time (steady state).

Question 23

Describe three Building Management System control levels commonly found in the built
environment.

Answer 23

• Field level where all the physical sensors, controlled devices live
• Automation level where the controller is implemented
• Management level is where the supervisory control and logging takes place

Question 24

Nine basic technologies are typically used in geothermal energy systems. List at least five of
these and briefly explain their main features.

Answer 24

Horizontal GHEX - Ground Heat Exchanger, is using your backyard or the bottom of lake or river etc. as a thermal battery. In this system cables is placed
beneath the ground or water surface to load heat or dissipate heat with help of the constant temperature in the ground or water.

Borehole HEX - Vertical Borehole GHEX is a effective conductive heat transport system, and the most common type is u-loop, but can also be a straight pipe system. The borehole is around 100-300m deep and 10-15 cm in diameter. The hole is filled with a collector tube which contains cold bearer fluid, for example
bioethanol water mixture.

Groundwater HEX
same type as when you do groundwater well for drinking water. mostly you are
looking for soft formation (tex clay) with groundwater flow. Mostly convective heat transfer. The temperature will be more even than the ground since you are extracting groundwater from the ground. You distract the water from the undisturbed ground.

BTES
BTES system contains several/multiples borrholes to a deep heat storag (resemling standard drilled wells) and can be used for cooling as for heating.
Very efficient for public and office buildings, because the fairly need a balance of cooling and heating.

ATES
ATES stand for Aquifer Thermal energy storage and is made of at least two wells (one cold and one warm well) that can draw from the same or different aquafiers. The cold well is used to store cold water and the warm well is used to store warm water. Depending if the building needs cooling or heating it will use a pump to reject either warm or cold water from the well and use it and then pump
to the other well.

Question 25

There are two basic concept types for closed loop borehole heat exchangers (=the piping in
the borehole). Name and describe both concept types, and list one advantage and one
disadvantage of each type

Answer 25

GPT: Closed loop borehole heat exchanger concept types are single U-tube and double U-tube. Single U-tube systems are easier to install but may have reduced efficiency. Double U-tube systems offer better efficiency but are more complex and costly.

Question 26

Long-term monitoring of ground source heat pump (GSHP) systems is important for several
reasons. Name at least two reasons why such measurements are needed and provide at least
one example of useful key performance indicators for each of these two needs.

Answer 26

GPT: Long-term monitoring of GSHP systems is needed to ensure system performance and energy savings. Key performance indicators include COP (Coefficient of Performance) and energy consumption.

Question 27

Within the IEA project Annex 52, a new system boundary concept with six system boundaries
was developed for ground source heat pump (GSHP) systems. What is included in these six
system boundaries and how is supplementary heating/cooling indicated?

Answer 27

GPT: The six system boundaries in GSHP systems include the ground, borehole, heat pump, distribution system, supplementary heating/cooling, and auxiliary energy systems.

Supplementary heating/cooling is indicated as a separate boundary. with a (+) sign next to the
number.

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Question 28

Provide the full names for each of the following performance indicators and explain how
they are used: COP, SCOP, PF and SPF.

Answer 28

GPT: COP (Coefficient of Performance) measures the efficiency of a heat pump,

SCOP is the seasonal COP and is calculated as the average
COP value at several standardized lab conditions that reflect different conditions over a full heating and/or cooling season.

PF (Performance Factor) is used for cooling systems and their efficency

SPF (Seasonal Performance Factor) measures seasonal efficiency.

EXTRA:

PF is defined as a ratio the delivered heating energy (qh), cooling energy (qc) or both and the energy used to deliver it (Electricity used to fans, compressors and circulation pumps). This performance factor is based on field meusured performance data from a
heat pump system over a defined period of time e.g. an hour, a day or a year and for a defined system boundary e.g. the heat pump unit itself or the entire
heat pump system including the source and load side circuits.
PF can be HPF, DPF, MPF, SPF and is for different defined periods. SPF stand for annual or seasonal. The system boundary level is denoted with a number.

Question 29

Explain the advantages and disadvantages of natural ventilation.

Answer 29

GPT: Natural ventilation is cost-effective and eco-friendly but relies on outdoor conditions. Disadvantages include limited control and effectiveness in extreme climates.

Question 30

List three common ventilation modes and explain their advantages and disadvantages.

Answer 30

CAV (Controllable Air volume)

+ Cheap and easy to install
+ Good for rooms with same size and demand
+ Bulidings/rooms with low solar radiation

• Bad for bigger buildings and offices
• Expensive operational cost
• Low Efficiency
• Same volume rate

VAV (Variable Air Volume)

+ Low operantional cost
+ Adjustable air volume
+ High efficiency
+ Usually easy to maintain
+ Works well for larger buildings

• Expensive investment cost

DCV (Demand controll ventilation)

+ High efficiency
+ controll by occupancy
+ Saving energy

• Expensive to install
• Controlled by CO2 sensors and not by occupants

Question 30

Explain the mechanism of stack ventilation

Answer 30

GPT: Stack ventilation uses the natural buoyancy of warm air to induce airflow. Hot air rises and escapes through high openings, drawing in cooler air from below.

EXTRA:

Stack effect or also called the chimney effect, is a vertical process and the most
used natural ventilation. This effect is can be very effective and inexpensive to achieve in a building design. Stack ventilation creates an airflow from the force
that appears when changes in air pressure, temperature and density levels between corresponding interal and external enviroments. Height and
temperature differenceses is the two main variables for this effect.

Warm air is lighter than cold air and therefor it rises and then it reduces the pressure in the base of the building. The warm air keeps rising and want to
escape out and new cold air wants to get in.

Pressure differences driven by two mechanism (air density difference and wind)

Warm air is less dense than cool air

Works when indoor air is warmer than outdoor air, harder to achieve this during
summer

Wind creates vaying surface pressured around the building

Question 31

What is exergy?

Answer 31

GPT: Exergy is a measure of the maximum useful work that can be extracted from a system at a given state, accounting for irreversibilities.

Question 32

Describe the advantages and disadvantages of electrical heating.

Answer 32

GPT: Advantages of electrical heating include simplicity and control, but it can be less energy-efficient and more expensive to operate.

Electric heating is when using electric energy and convert it to heat

Advantages
- No pollutions (neat and clean atmoshpere)

• No noise is produced
• Low radiating losses
• Easy to control, you can start instantly and stopped when you want. Fast when turning on.
• temperature control
• Cheap installation cost
• High efficency, 75% to 100% of the electric energy in is being converted to heat energy. = High exergy
• Low maintanace cost

Disadvantages
- expensive run cost, electricity is expensive.

• Bad for heating large spaces
• Electric hazards, fire

Question 33

Why is it more difficult to cool an indoor space to a temperature below the ambient
temperature than to heat it to a temperature above the ambient temperature?

Answer 33

GPT: Cooling below the ambient temperature requires energy input to remove heat, making it more challenging than heating.

EXTRA:
It is because of the second law of thermodynamics. There are many irreversible processes that can be used to heat something. It is the natural flow of things
because entropy will increase in isolated systems, and much of the internal energy of objects can be dissipated as heat. However, to cool something you need to perform work according to the Clausias statement of 2nd law. There is a maximum efficiency, the COP, for work to be used to cool something by removing heat from one source at lower temperature and move it to a source at a larger temperature

Question 34

What are Thermally Activated Building Systems (TABS)?

Answer 34

GPT (Behöver utvecklas):
Thermally Activated Building Systems (TABS) use building structures to store and distribute heating or cooling energy, providing thermal comfort.

Question 35

Why are heat pumps suitable as a source of heat for floor heating systems?

Answer 35

Floor heating system is ideally toghether with any heat pump, but only for geothermal systems. Floor heating have a low system temperature, don’t exceed
26 degrees will higher the performance of the heat pump (better COP). The heat pump, condesor, solar thermal is designed at lower temperatures and there for works perfect with floor heating. (Smaller temperature differences)

Question 36

Draw a graph comparing for different stages of a building project the cost of making project
changes to the ability/possibility of making effective changes.

Answer 36

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GPT: The cost of making project changes increases as the project progresses, and the ability to make effective changes decreases.

Question 37

Explain the concept of “Trias Energetica”.

Answer 37

Tänk logiskt för att utveckla svaren mer.

The Trias Energetica is a sustainable energy concept that consists of three main steps:

1. Reduce energy demand
2. Utilize Renewable energy
3. Select energy source (Efficient use of Fossil fules as a last resort)

EXTRA (finns ännu mer)

1. Reduce energy consumption, ask qustions and check if we really need everything?
2. Use sustainable energy, control what you are using
3. Diffucult to predict energy consumtion, and the maximum. No one want to take risk and over dimension the generators. When generating to much energy
   then necessary will increase cost and emissions.

Question 38

Explain the passive space-conditioning concepts of “ground heating” and “ground cooling”.
Illustrate both concepts with simple sketches.

Answer 38

The passive space-conditioning concept for ground cooling is an earth-air heat exchanger (EAHX). This i a geothermic solution that are made with a buried pipe
system circulating fresh air. It aims at warming up fresh air in buildings in winter
and cooling it down in summer periods.

This technique preheats the air in the winter and and vice versa in the summer. The temperature of the earth at depth to 1,5 to 2 metres remains fairly
constant. The temperature in the ground is higher than the ambient air temperature in the winter and lower than ambient temperature in the summer.

The air is drawn through the pipes where there is constant temp. and get preheated or precooled and will reduce heating and cooling load passively.

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Question 39

Explain the passive space-conditioning concepts of “cool roofs”. Illustrate the concept with a simple sketch.

Answer 39

Normal roofs uses material which is:
- High absorbent (absorb a lot solar radiation)
- Low reflectance
- Low heat emittance

Cool roofs use materials which is instead:
- Low absorbance
- High solar reflectance
- High heat emittance
- Allow the building to remove stored heat by radiation

Some cool roofs will also use evaporation to lower heat gains.

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Question 40

Discuss the advantages and disadvantages of the passive space-conditioning concept of
“green roofs”

Answer 40

Advantages:
- Improves the aesthetics, looks nice

• can improve the air quality if thick enough with variety of vegetation and allow
  growth of larger plats.
• Can mitigate the urban heat island effect IF thick enough
  Improve building insulation somewhat
• Have a cooling effect due to evaporation
• Provide habitat to local fauna

Disadvantage:
- Increase risk for building damages (Water leakege, moisture)

• Heavy - stronger construction - more expansive
• Harder to inspect

Question 41

What are “thermal heating or cooling loads” and how do they impact indoor thermal
comfort?

Answer 41

GPT:
Thermal heating or cooling loads are the heat transfer requirements for maintaining the desired indoor temperature, impacting the energy needed for HVAC systems.

Thermal heating or cooling loads is the heat or coolth that is delivered to a system to achieve, restore and maintain a certain desired level of thermal
comfort in indoor environments.

A thermal load is any heat flow that needs to be compensated for by heating or cooling in order to maintain the desired indoor thermal environments.

Question 42

Using a simple sketch, identify the principal heat gains and losses in a building.

Answer 42

GPT: Principal heat gains in a building include solar radiation, internal heat sources, and outdoor air. Principal heat losses include conduction, convection, and infiltration.

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Question 43

Describe the terms “sensible heat flow” and “latent heat flow”.

Answer 43

GPT:
Sensible heat flow is the heat transfer associated with a change in temperature, while latent heat flow is the heat transfer related to a change in moisture content.

Sensible heat flow
You can refer it to temperature you can feel. It’s the amount of energy required to change the temperature of a substance with no phase change. The temperature change can come from sun absorbtion or warmer air from ventilation etc.

Latent heat flow
Latent heat is energy absorbed by or released from a substance during phase change from a gas to liquid or vice cersa. Boiling water is a good example, when
boiling over a stovr, energy is being absorbed from the heating elemern (stove) and goes into expanding the water molecules into a gas, known as vapor istead
of changing the temperature further