1 Predavanje Energetske karakteristike zgrada
by @user_221e3db
117
0
0
Jun 14, 2026
About this deck
This deck includes 117 flashcards covering internal energy, celsius scale, thermal motion, and related concepts. Use it to review key Chemistry ideas, focus on weak cards, and prepare for your exam with StudyLess.
Study this deck in StudyLess
Save to your library and review with FSRS spaced repetition.
Flashcards
117 total- 01
What happens when a heated body is placed in cold water?
The heated body transfers heat to the cold water, causing the water to warm up.
- 02
What is the spontaneous transfer of heat?
Heat is energy that spontaneously transfers from a body with higher temperature to a body with lower temperature until their temperatures equalize.
- 03
Under what condition does heat transfer occur between bodies?
Heat transfer occurs between bodies that are in thermal contact.
- 04
When are two bodies at different temperatures considered in thermal contact?
Two bodies at different temperatures are in thermal contact when there is no thermal insulator between them.
- 05
When does heat transfer cease between bodies in thermal contact?
Heat transfer ceases when the temperatures of the bodies in thermal contact become equal.
- 06
What is the symbol and unit for heat?
The symbol for heat is Q, and its unit is the joule (J).
- 07
What is the Zeroth Law of Thermodynamics?
If bodies A and B are each in thermal equilibrium with body T, then A and B are in thermal equilibrium with each other.
- 08
What does the Zeroth Law imply about temperature?
Every body has a property called temperature, and when two bodies are in thermal equilibrium, their temperatures are equal.
- 09
What is the unit of temperature?
The unit of temperature is the degree Celsius [°C], also known as the Celsius degree.
- 10
Who proposed the Celsius scale and when?
Anders Celsius proposed the Celsius scale in 1742, using the freezing and boiling points of water at normal pressure as reference points.
- 11
How did Celsius initially assign values to freezing and boiling points?
Celsius assigned 100° to the freezing point and 0° to the boiling point.
- 12
What is the official SI unit for temperature?
The official SI unit for temperature is the Kelvin.
- 13
What temperature does -273.15°C correspond to in Kelvin?
-273.15°C corresponds to 0 Kelvin.
- 14
How does temperature relate to heat?
A hotter body has a higher temperature, and a colder body has a lower temperature.
- 15
What is absolute zero?
Absolute zero is the lowest possible temperature in the universe.
- 16
Which country officially uses the Fahrenheit scale?
The Fahrenheit scale is officially used in the USA.
- 17
What is internal energy?
Internal energy is the sum of all energies of all atoms within a body.
- 18
How does heating affect a body's internal energy?
When a body receives heat, its internal energy increases, and its temperature rises.
- 19
How does losing heat affect a body's internal energy?
When a body loses heat, its internal energy decreases, and its temperature falls.
- 20
What is heat?
Heat is the energy that transfers from one body to another.
- 21
What is the relationship between heat and internal energy?
A body does not 'possess' heat; it possesses internal energy. Heat is the transfer of a part of that internal energy.
- 22
What is thermal motion?
Thermal motion is the vibration of atoms around their equilibrium positions in solids, or their movement in gases and liquids.
- 23
What is the kinetic energy of thermal motion?
Every vibrating system, from a weight on a spring to atoms in a solid, has kinetic energy.
- 24
How does the amplitude of vibration relate to energy?
The greater the amplitude of vibration, the greater the energy.
- 25
What is internal energy composed of?
Internal energy is the sum of the kinetic and potential energies of the molecules within a body.
- 26
What is temperature?
Temperature is a physical quantity used to describe how heated a body is.
- 27
How did Carl von Linné modify the Celsius scale?
Carl von Linné reversed the values, assigning 0° to the freezing point and 100° to the boiling point, which is the standard today.
- 28
What does 'heat' signify?
Heat signifies energy in transit.
- 29
What is the formula for Richmann's rule?
m₁c₁(T - T₁) = m₂c₂(T₂ - T)
- 30
What do the variables in Richmann's rule represent?
m₁ = mass of the colder system, c₁ = specific heat capacity of the colder system, T₁ = thermodynamic temperature of the colder system; m₂ = mass of the warmer system, c₂ = specific heat capacity of the warmer system, T₂ = thermodynamic temperature of the warmer system; T = thermodynamic temperature of the mixture.
- 31
What is heat transfer?
Heat transfer (or heat) is thermal energy in transit due to a spatial temperature difference.
- 32
When does heat transfer occur?
Whenever there is a temperature difference in a medium or between media, heat transfer must occur.
- 33
How many possible ways can heat be transferred?
There are three possible ways of heat transfer.
- 34
What are the three modes of heat transfer?
The three modes of heat transfer are convection, conduction, and radiation.
- 35
What is convection?
Convection is the transfer of energy by the movement of fluids (liquids or gases).
- 36
How does convection occur?
Convection occurs due to density changes caused by heating. Warmer, less dense fluid rises, while cooler, denser fluid sinks.
- 37
What is conduction?
Conduction is the transfer of energy through direct contact, from particle to particle, without the movement of the material itself.
- 38
How does conduction occur in solids?
In solids, conduction occurs through vibrations of particles.
- 39
What is radiation?
Radiation is the transfer of energy through electromagnetic waves.
- 40
Can radiation occur in a vacuum?
Yes, radiation can occur in a vacuum, such as heat transfer from the Sun to the Earth.
- 41
What is heat flow?
Heat flow (Φ) is the amount of heat transferred per unit of time, measured in Watts (W = J/s).
- 42
What is heat flux?
Heat flux (q) is the heat flow per unit area, measured in W/m².
- 43
What is thermal conductivity?
Thermal conductivity (λ) is a material property that describes how well it conducts heat.
- 44
What does a high thermal conductivity value indicate?
A high thermal conductivity value indicates that the material is a good conductor of heat.
- 45
What does a low thermal conductivity value indicate?
A low thermal conductivity value indicates that the material is a good insulator of heat.
- 46
What factors influence thermal conductivity?
Thermal conductivity depends on the material's composition, density, porosity, moisture content, and temperature.
- 47
How does density affect thermal conductivity?
Materials with higher density generally have higher thermal conductivity.
- 48
How does moisture affect thermal conductivity?
Increased moisture content generally increases thermal conductivity.
- 49
What is thermal resistance?
Thermal resistance (R) is a measure of a material's opposition to heat flow.
- 50
What is the formula for thermal resistance of a homogeneous layer?
R = d / λ, where d is the thickness and λ is the thermal conductivity.
- 51
How can thermal resistance be increased?
Thermal resistance can be increased by increasing the thickness of the layer or by using materials with lower thermal conductivity.
- 52
What is the total thermal resistance of a building element?
The total thermal resistance (R_T) is the sum of the thermal resistance of each layer and the surface resistances.
- 53
What is the formula for total thermal resistance?
R_T = R_si + R₁ + R₂ + ... + R_n + R_se, where R_si is the internal surface resistance, R₁ to R_n are the resistances of the layers, and R_se is the external surface resistance.
- 54
What is the U-value?
The U-value (coefficient of heat transfer) is a measure of how well a building element conducts heat.
- 55
How is the U-value related to thermal resistance?
The U-value is the reciprocal of the total thermal resistance: U = 1 / R_T.
- 56
What does a lower U-value indicate?
A lower U-value indicates better thermal insulation of the building element.
- 57
What are the internal and external heat transfer coefficients?
αᵢ is the internal heat transfer coefficient, and αₑ is the external heat transfer coefficient.
- 58
What is the building envelope?
The building envelope (or shell) consists of all the building elements that separate the conditioned interior from the unconditioned exterior.
- 59
What is the building shape factor (f₀)?
The building shape factor (f₀) is the ratio of the building's envelope area (A) to its heated volume (Vₑ), expressed in m⁻¹.
- 60
How does the shape factor affect energy consumption?
Buildings with a more complex shape (higher f₀) have a larger envelope area relative to their volume, leading to higher heat loss and thus greater energy consumption for heating.
- 61
What is the thermal quality of opaque building elements?
The thermal quality of opaque elements refers to their ability to resist heat flow, primarily determined by their thermal resistance (U-value).
- 62
What is the thermal quality of transparent building elements?
The thermal quality of transparent elements (windows, doors) depends on factors like the number of glass panes, the type of glazing, the frame material, and the sealing.
- 63
What is the typical ratio of opaque to transparent elements in residential buildings?
In residential buildings, the ratio of opaque to transparent elements is typically 3:1 to 4:1.
- 64
What is the unit for the Kappa value?
The unit for the Kappa value is kJ/m²K.
- 65
What is solar radiation (insolation)?
Solar radiation is energy from the sun that travels through space as electromagnetic waves.
- 66
How much solar energy reaches Earth's atmosphere?
Approximately 1350 W/m² of solar energy reaches Earth's atmosphere.
- 67
What factors affect the intensity of solar radiation reaching the surface?
The intensity of solar radiation reaching the surface depends on the angle of incidence, atmospheric clarity, cloud cover, and the sun's altitude.
- 68
What is reflected or diffuse solar radiation?
Reflected or diffuse solar radiation is sunlight that has been scattered by the Earth's surface and other objects in the atmosphere.
- 69
What determines the absorption of solar radiation by a building element?
The amount of absorbed solar radiation depends primarily on the color of the building element's surface.
- 70
How does surface color affect solar absorption?
Darker colors absorb more solar radiation than lighter colors.
- 71
What is the difference in solar radiation effects on opaque and transparent elements?
Opaque elements absorb and reflect solar radiation, while transparent elements allow some radiation to pass through.
- 72
What is the optimal solar strategy for buildings in continental climates?
In continental climates, the need for solar energy is inversely proportional to the intensity of solar radiation throughout the year.
- 73
What is the solar strategy for winter?
In winter, it is desirable to maximize solar heat gain through transparent elements.
- 74
What is the solar strategy for summer?
In summer, effective shading is needed to prevent overheating.
- 75
What are thermal bridges?
Thermal bridges are parts of the building envelope that have significantly lower thermal resistance than the surrounding areas.
- 76
What are the consequences of thermal bridges?
Thermal bridges lead to unnecessary heat loss in winter and can cause condensation on interior surfaces.
- 77
How can thermal bridges be mitigated?
Thermal bridges can be mitigated by adding insulation to these areas, typically from the exterior.
- 78
What is thermal mass?
Thermal mass is the ability of building materials to absorb, store, and release heat.
- 79
Where should thermal insulation be placed?
Thermal insulation should always be placed on the exterior side of the building envelope.
- 80
What is the Kappa (κ) value?
The Kappa (κ) value, or surface thermal capacity, measures a building element's ability to store heat per unit area.
- 81
What does a higher Kappa value indicate?
A higher Kappa value means the material can store more heat, leading to slower temperature changes (greater thermal inertia).
- 82
What is the formula for calculating the Kappa value?
κ = 10⁻⁶ Σ ρᵢ ⋅ cᵢ ⋅ dᵢ, where ρᵢ is density, cᵢ is specific heat capacity, and dᵢ is thickness of each layer.
- 83
What is the primary factor influencing thermal stability in summer?
The primary factor influencing thermal stability in summer is the building envelope's ability to maintain a relatively constant internal surface temperature despite external temperature fluctuations.
- 84
What are the key climate characteristics affecting building design?
Key climate characteristics include the average monthly temperature of the coldest month, solar radiation intensity, and wind patterns.
- 85
What is the role of microclimate in building design?
Microclimate factors within a building (e.g., heat from appliances, occupants) can affect energy consumption and thermal comfort.
- 86
How do heating and cooling systems relate to the building envelope?
Heating and cooling systems should be designed to complement the thermal characteristics of the building envelope to optimize energy efficiency.
- 87
What is the importance of passive solar energy?
Passive solar energy utilization, through proper building design and orientation, can significantly reduce heating and cooling loads.
- 88
What is the primary factor for rational energy consumption and thermal comfort in buildings?
The primary factor is the thermal quality of the building envelope.
- 89
How does building age affect thermal quality?
Older buildings, particularly those constructed before the widespread adoption of modern insulation standards, generally have lower thermal quality.
- 90
Why is thermal mass important in winter?
Thermal mass helps to maintain a more stable indoor temperature, especially when heating systems are intermittent, by releasing stored heat during colder periods.
- 91
What is thermal capacity?
Thermal capacity is the ability of a body to store a certain amount of thermal energy, determined by its thermal capacity.
- 92
Why are some substances easier to heat than others?
It is known from personal experience that some substances are easier to heat or cool than others.
- 93
Example of different heating rates for equal masses
For example, with the same heat source, it is harder to heat a certain mass of water than a piece of iron of equal mass.
- 94
Example of different cooling rates
Similarly, water will cool more slowly under the same environmental conditions than a piece of iron of equal mass.
- 95
What does the heating of a substance depend on?
It is concluded that the heating of a substance depends on the type of material it is made from.
- 96
What is the relationship between heat required and temperature change?
Experimentally, the amount of heat needed to raise the temperature of a substance from T1 to T2 is proportional to the temperature difference (ΔT = T2 - T1).
- 97
How is the proportionality sign replaced with an equality sign?
To replace the proportionality sign with an equality sign, a proportionality constant C must be introduced.
- 98
What is the formula relating heat, constant, and temperature change?
Q = C ⋅ ΔT
- 99
What is the constant C in the equation Q = C ⋅ ΔT called?
The constant of proportionality in this equation is called thermal capacity.
- 100
How is thermal capacity defined?
Thermal capacity is the quotient of the heat supplied to a body and the resulting temperature increase.
- 101
What are the units for thermal capacity?
The unit for thermal capacity is J/K or JK⁻¹.
- 102
How does mass affect thermal capacity?
Experiments and measurements have shown that as the mass of a substance increases, its thermal capacity also increases.
- 103
Why is it easier to change the temperature of a smaller mass?
It is known that it is easier to achieve a certain temperature change by heating a smaller mass of a substance than by heating a larger mass of the same substance.
- 104
What does the constant C in Q=C∙ΔT depend on?
The constant C in the equation Q=C∙ΔT depends on the thermal properties of the substance and its mass.
- 105
What new physical quantity is defined because C depends on mass?
Therefore, a new physical quantity called specific heat capacity is defined.
- 106
What is specific heat capacity?
Specific heat capacity is a physical quantity that expresses the amount of heat required to raise the temperature of a unit mass of a substance (1 kg) by one degree of temperature (1 °C or 1 K).
- 107
What is the formula for specific heat capacity (c)?
c = C / m
- 108
What is the formula for specific heat capacity (c) in terms of Q, m, and ΔT?
C = Q / (m ⋅ ΔT)
- 109
What are the units for specific heat capacity?
The unit for specific heat capacity is J/(kg K) or J(kg K)⁻¹.
- 110
What is the formula for the amount of heat transferred (Q) given mass (m), specific heat capacity (c), and temperature change (ΔT)?
Q = m ⋅ c ⋅ ΔT
- 111
What is the device for measuring specific heat capacity called?
The device for measuring specific heat capacity is called a Richmann calorimeter.
- 112
How is a calorimeter designed?
A calorimeter is a well-insulated container whose walls are filled with a thermal insulator to prevent heat exchange with the surroundings.
- 113
What is the most common insulator in a calorimeter?
The most common insulator in a calorimeter is air.
- 114
What happens when a substance is mixed with another in a calorimeter?
When a liquid of mass m₁ and temperature T₁ is added to a calorimeter containing another liquid (or a solid is immersed), heat transfers from the substance with higher temperature to the substance with lower temperature until thermal equilibrium is reached.
- 115
What is the final temperature called in a mixture?
The common temperature is called the mixture temperature T.
- 116
What is Richmann's rule (method of mixtures)?
Ignoring heat transfer to the surroundings (losses), Richmann's rule applies.
- 117
What does Richmann's rule state?
Richmann's rule states that the amount of heat absorbed by the colder body equals the amount of heat released by the warmer body.
Related decks
Make your own deck.
Snap a photo of your notes and StudyLess generates flashcards in seconds, then schedules every review backward from your exam date.