Figure 5.7 External interface created as an Excel workbook

- Modify the EnergyPlus source code (for the more confident modeller with software development experience).

This way the alternative interface (generic model) can give the users high certainty that the achieved results are correct and can also contribute to the improvement of their knowledge, expertise in and feeling for simulation.

External interface created as an Excel workbook, through which the selected parameters of the created generic simulation model of a family house are entered or changed.

Figure 6.7External interface created as an Excel workbook

External interface to control the generated generic simulation model of the house - table with the loaded results and graphics for displaying the building energy performance and indoor comfort graph. The "RunCapsol" button starts the calculation in the CAPSOL simulation software.

Figure 6.8External interface to control the generated generic simulation model of the house

Glossary

The Glossary is loosely based on the publications Fundamentals of Heat and Mass Transfer [2] and Energy Conscious Design - A Primer for Architects [3] (concepts related to heat transfer and water vapour diffusion) and on Physics of the Indoor Environment of Buildings [1] (concepts related to air movement).

Thermodynamics - a discipline of physics describing natural phenomena related to the energy side of systems and their changes, i.e. laws of heat and thermal processes, relations between quantities characterizing the macroscopic state of a thermal system and changes of these quantities in physical processes associated with heat exchange between the system and its environment. It has three main laws - the law of conservation of energy, the law of impossibility of heat transfer from a colder to a warmer body and the law of behaviour of substances near absolute zero.

The science of heat transfer - based mainly on the first and second laws of thermodynamics, heat transfer (or heat propagation) is the exchange of thermal energy between physical systems. The rate of heat transfer depends on the temperature of the systems and the properties of the intervening media through which the heat is transferred. There are three basic modes of heat transfer: conduction, convection and radiation.

Building physics - a scientific discipline dealing with physical problems in the field of building construction. It has three main branches: building thermal engineering, acoustics and day lighting of buildings

Numerical computational methods - they serve to bridge the gap between the theory of mathematics and its practical application, since few problems described by mathematics can be solved completely accurately, even if the inputs are unambiguously specified. A numerical method is a precisely described procedure to solve a numerical problem. Every numerical method should include an error estimate. The basic characteristics of any numerical method are stability and convergence.

Heat - one of the forms of energy. It manifests itself as molecular motion in a body, liquid or gas or also as radiation in space. Heat is given in Joules, like other forms of energy.

Mass heat capacity (Cp) - the amount of energy required to raise the temperature of a given substance of unit mass by 1 Kelvin. It is given in J/(kg.K). The mass heat capacity of liquids varies with temperature and pressure. Older names for this quantity were specific heat capacity, specific heat, or just heat capacity.

Volumetric heat capacity - is the product of the mass heat capacity (Cp) and the volumetric mass (kg/m3) of the material and is expressed in J/(m3K).

Sensible heat - can be perceived or measured. If the sensible heat of an object increases, its temperature also increases, and vice versa. This happens without any change in the state of the object, e.g. from a solid to a liquid state.

Latent heat - is the heat required to induce a change in the state of a substance, e.g. from solid to liquid. This change of state takes place at a constant temperature. The same amount of heat must always be supplied or removed to reverse the change of state, e.g. water to ice / ice to water.

The laws of thermodynamics

• First law: the law of conservation of energy. Energy exists in different forms. It cannot be created or destroyed. It can only change from one form to another. In any system, the input energy is equal to the energy output plus the change in stored energy. • Second law: the energy transfer is spontaneous and only in one direction. Always from a higher level to a lower level. In thermal energy, the transfer of heat takes place from a warmer body towards a colder one. It is not possible to reverse the direction of heat transfer without any external input of energy.

Thermal inertia - is an expression of the resistance of a body to a change in its temperature. It depends on its volumetric heat capacity and its thermal resistance.

Heat flux ( ) - is the transfer of heat in the direction from a higher temperature to a lower temperature. Heat flux therefore assumes both a heat source and a temperature gradient. Heat transfer occurs by conduction, convection and radiation. The rate of heat transfer through a body or space is the amount of energy passing through it per unit time, expressed in J/s or Watts. The heat flux density, q, is the rate of heat flux per unit area and is expressed in W/m2 .

Heat conduction - heat can be transferred through the object by conduction. It is a molecular movement by which heat spreads gradually through an object or between objects in direct contact. The extent of heat transfer through the object(s) depends on the size of the area considered perpendicular to the direction of heat transfer, the thickness of the object, the temperature difference between the two points considered and the thermal conductivity of the material.

Thermal conductivity coefficient () - is defined as the rate of heat flux through a unit area and unit thickness of a given substance at a unit temperature difference between its surfaces. The lower the value, the better the thermal insulating effect of the substance. The coefficient of thermal conductivity is given in W/(m.K) and expresses the ability of a substance to conduct heat.

The resistance of a substance to conduction of heat (r) is the inverse of the coefficient of thermal conductivity, 1/ = r (m.K/W).

Thermal resistance (R) - is the product of the resistance of a substance and its thickness (m2K/W).

Heat transfer coefficient (U) - is the inverse of the thermal resistance, 1/R = U (W/(m2.K)). It represents the amount of heat transferred through a square metre of a material or multimaterial component at a temperature difference of 1 K between its inner and outer surface.

Convection- is the transfer of heat from the surface of a solid to a fluid (gas or liquid) or vice versa from a fluid to a solid. The rate of heat convection depends on the contact area, the temperature difference between the solid and the fluid, and the conductive heat transfer coefficient, the value of which depends on the geometry of the conduction, the viscosity and velocity of the fluid, and also on whether the fluid conduction is laminar or turbulent.

Radiation - heat can be transferred through space (in a vacuum or in a permeable or semipermeable medium) in the form of radiation from one body to another. The range of the wavelength spectrum of radiation depends on the nature and the surface temperature of the body. The amount of radiant heat flux depends on the temperature of the emitting and receiving surfaces, respectively on the emissivity and absorptivity of these surfaces. Solar energy reaches the Earth's surface in the visible band of the solar radiation spectrum, in the long-wave bands as infrared radiation and in the short-wave bands as ultraviolet radiation.

Emissivity () - is the ratio of the thermal radiation from a unit area of the surface of a body to the radiation from a unit area of a perfect emitter, i.e. a blackbody, at the same temperature, or the ratio between the radiant flux density of the grey body, qs, and the radiant flux intensity of the blackbody, qb.

Dalton's law - the total pressure exerted by a mixture of gases is equal to the sum of the (partial) pressures that the individual gases would exert if they each occupied the same volume at the same temperature. This means that each of the gases in the mixture behaves as if the other gases were not present, and that the pressures coming from the individual gases in the mixture can simply be added together. It is assumed that there are no chemical reactions between the gases. Dalton's law applies to so-called ideal gases (source: Wikipedia). It also applies to a mixture of air and water vapour.

Water vapour diffusion - the movement of water vapour in a material based on its partial pressure difference.

Diffusion resistance factor () - indicates the number of times the material's resistance to water vapour diffusion is greater than the resistance of the air ( air = 1)

Equivalent diffusion thickness (sd ) - this is the thickness the air layer would need to have in order for its resistance to water vapour diffusion to equal the resistance of the material in question. It is given in metres.

Water vapour condensation - a thermodynamic process in which water changes from the gas to the liquid phase. It occurs at the dew point temperature, which is the temperature corresponding to 100% relative humidity at constant pressure

Air permeability - The movement of air in a structure by a pressure difference, from a higher pressure to a lower pressure, provided that the fabric of which the structure is made is porous, the pores are also interconnected, and/or the joints and cracks in the structure are leaky and air-permeable.

Air infiltration - characterises the air permeability through the structure. It is the volumetric flow of air at defined conditions expressed as a function of the pressure difference

Air exchange - occurs during air infiltration and/or forced ventilation and is defined by the air change rate in 1/hr.

Selectivity (S-value) - The choice of suitable glass depends primarily on the requirements for indoor well-being in the planned room, and these can be quite contradictory. For example, in an office space we need to achieve the best possible daylighting, but we also want to avoid

overheating. The use of a low-emissivity coating reduces the light transmittance of the glass or glazing system, which is an unwanted side effect of reducing the solar factor. Therefore, in addition to the g- and U-values of the glass, the glass manufacturers also indicate the socalled selectivity of the glass or glazing systems to demonstrate their suitability in terms of these conflicting requirements. The selectivity or selectivity factor is the ratio of the optical transmittance, opt, to the g-value. The higher it is, the more suitable the glass or glazing system is in terms of the conflicting requirements for light comfort and reduction of summer overheating. The maximum selectivity value achievable with current technologies is around 2.