4.3.3. Building data<br>

### 4.3.3. Building data

In this position there are general data of building, information about its location, occurring shading elements, indexes of internal heat gains in a building and selected climatic data. This is full scope of data required for calculation of seasonal energy demand in a building. After this calculation function will be switched off, there will be fewer data for edition. Scope of displayed edition fields depends on declared calculation options.

In this position are entered general building data, information concerning its location and selected climatic data. Scope of displayed edition fields depends on declared calculations options.

If the User has selected the calculation method of interruption of central heating system operation, additional edition fields have to be completed.

Here is also a tab “Catalogue service” enabling selection of required catalogues. After clicking a selected button, the User can select climatic data from the tab “Climatic data”.

Data are to be entered in following fields:

Location

In field „Location” select the place from catalogue of climatic data in which the building is located. The next meteorological station and corresponding actinometrical station and climatic zone are selected automatically by the program. If the climatic data will not be loaded from catalogue, the User has to complete the fields of location name and climatic zone by himself. Moreover, it is impossible to complete manually data of meteorological and actinometrical station.

! For calculation of seasonal energy demand the User has to select the catalogue of climatic data and use it in project. Otherwise performing of these calculations will be impossible because of lack of sufficient climatic data.

Meteorological station

In this field is displayed a meteorological station responding to specific city.

Actinometrical station

In this field is displayed a closest actinometrical station appropriate for a meteorological station selected below. This data specify set of climatic data indispensable for calculations of seasonal energy demand of a building.

te/θe (Outer temperature)

Depending on selected location the program will give the value of outer temperature, that means this temperature will be assigned to climatic zone. If no catalogue of climatic data has been selected in the project, the User has to enter the temperature value by himself.

θme (average annual outer temperature)

Depending on selected location the program will give the value of average annual outer temperature. If the climatic data catalogue has not been selected in the project, then the User has to enter its value by himself.

n50 – multiplication factor of exchanges at difference of 50 Pa

Multiplication factor of air exchanges in the building, determined at pressure difference of 50 Pa between building interior and external environment. For automatic calculations designated with icon the value depends on the type of building construction and its air-tightness:

- for a one-family building with high grade of air-tightness n50<4; for a building with middle air-tightness class n50 is in range between 4-10; for a building with low class of air-tightness n50>10.

- for a multi-family or not inhabited building with high air-tightness grade n50<2; for a building of middle class of air-tightness n50 is in range between 2-5; for a building with low air-tightness class n50>5.

The User can also declare the value in this field switching to the icon .

η – efficiency of heat recovery system

This field is used for determining of heat recovery efficiency from warm air removed from a flat. If the blown air is heated in central heater located in the building, this efficiency has to be specified. In case of lack of heat recovery, its value is equal to zero. After declaring of “η”-value the thermal load will be properly calculated in the building with mechanical ventilation.

P – floor perimeter on the ground

Floor perimeter on the building ground will be calculated taking into consideration these dimensions, which are in contact with external environment. The perimeter value can be calculated automatically after switching to the icon and after completing of dimensions of plan view of the building in fields “bbud – building width” and “abud – building length” Calculations of “P” concerns this building, which has in its block both heated and non-heated compartments. If a non-heated compartment is not included in main block – e.g. garage, the dimensions of these compartments should not be taken into consideration for calculations. The calculation method has been presented in example below.

B’ – characteristic dimension of building

Characteristic dimension of building is always calculated by the program after completing the floor perimeter on the ground of building in field “P” and the area of floors on the ground in field “Abud”. The method of calculation of B’-value has been presented in APPENDIX B. APPLIED NORMS AND CALCULATION METHODS.

T (Depth of underground water)

This field specifies the distance between the level of underground water and floors on the ground of a building. It will be completed with a program default value, it can also be edited by the User. It will be displayed for calculation option of heat loss to the ground by means of simplified method according to EN 12831.

bbud – building width

The value completed by the User according to outer dimensions of building plan view. The program can calculate dimensions automatically on the basis of building view loaded from Instal-therm program. Program gives us a possibility of switching between calculation modes by means of icon for automatic calculations – this icon is common for both horizontal building dimensions and by means of icon enabling enforcing this value. An example illustrating correct interpretation of this value has been presented below.

abud – building width

The value completed by the User according to outer dimensions of building plan view. The program can calculate dimensions automatically on the basis of building view loaded from Instal-therm program. Program gives us a possibility of switching between calculation modes by means of icon for automatic calculations – this icon is common for both horizontal building dimensions and by means of icon enabling enforcing this value. An example illustrating correct interpretation of this value has been presented below.

An example illustrating correct calculations of building perimeter and area of floors on the ground

Generally there are two possible cases related to the value of length and width of building:

7. First case concerns a free-standing building.

In case of calculations of building perimeter on the ground it is necessary to take into consideration the horizontal dimensions of building plan view – length and width of plan view, having contact with external environment. The building can contain both heated and non-heated compartments.

Building, to which the heat calculations are related

Drawing 1. Plan view of free-standing building – ground floor

P=2abud+2bbud=36 m

Abud=abud*bbud=80m2

where:

P – perimeter of floor on the ground

Abud – area of floors on the ground

abud – length of building

bbud – width of building

2. Second case concerns the segment of a row type buildings.

In case of calculation of building perimeter on the ground, it is necessary to take into consideration the horizontal dimensions of building plan view – length and width of plan view having contact with external environment. The building can contain both heated and non-heated compartments.

Segment, to which the heat calculations are related

Drawing 2. Plan view of building segment – ground floor

P=2abud+2bbud=16 m

Abud=abud*bbud=80m2

where:

P – perimeter of floor on the ground

Abud – area of floors on the ground

abud – length of building

Abud – area of floors on the ground

The User can complete by himself according to the sum of floors area on the ground in the building. After selecting the icon calculations are performed automatically on the basis compartments on the ground declared in building structure.

z’ – building depression

A field informing about the distance between floor on the ground and the ground level. To be filled in by the User on the basis of project data.

Edition fields are displayed in case of selecting of calculations of temporary temperature reduction according to data declared for the building:

cwirk – effective mass of building

Index determining the ability of heat accumulation by the building mass. Value of this field can be calculated automatically by the program or can also be enforced by the User. The selection depends on the method of inserting of partitions into compartments.

- if the partitions features are directly declared in compartment, then the cwirk-value can be entered by the User or can be selected from a pop-up list depending on the building from following possibilities:

· light – 15 Wh/ (m3K)

· medium – 35 Wh/ (m3K)

· heavy –50 Wh/ (m3K)

- if partitions in compartment will be declared from definitions, the value of effective mass of building can be calculated automatically on the basis of declared data. The User can also complete the field with a value known for the building or select it from a list among above mentioned possibilities: light, medium, heavy.

tabs – time of temperature reduction

Field completed with the value of temperature reduction time assumed in compartments. For each new opened project a default value assumed in program will be displayed.

nAbs – multiplication factor of exchanges in the temperature reduction phase

Field completed according to project assumptions. For each new opened project a default value assumed in program will be displayed.

ΣHT,τ – heat loss by penetration coefficient

This field is completed automatically by the program after selecting the icon on the basis of partitions entered in compartments. After selecting the icon the field is to be completed by the User.

Vnetto – heated cubic capacity

This field is completed automatically by the program after selecting the icon on the basis of cubic capacity of heated compartments, in which temporary temperature reduction has been declared.. After selecting the icon the field is to be completed by the User.

ΔφRH – temperature drop after reduction phase

Value of this field is calculated according to data completed in program. It is also possible to switch to manual method of value input. To switch between calculation modes use in succession icons and . Explanation of calculation mode application has been described in APPENDIX B. APPLIED NORMS AND CALCULATION METHODS

tRH - time of warming-up

Field to be completed by the User on the basis of known warming-up time of reduced temperature in compartment to required value.

nRH - multiplication factor of exchanges during warming-up

Field completed according to project assumptions. For each new opened project a default value assumed in program will be displayed.

Building rotation

Using the button „Building rotation” the User can determine the rotation angle defined according to „compass” pointing all cardinal points of the compass. Orientation of partitions declared in project can be changed by selecting of rotation angle on the “compass”. The User can do this selecting the direction (cardinal point of the compass). The building will rotate by an absolute angle determined towards initial position. After change of these data all orientations of external partitions will be corrected. By importing of project from version 3.2 it is possible to define here the same rotation angle, which has been declared in previous program version.

Type of building construction

The User can select from a pop-up list following options:

- One-family house

- Multi-family house or other.

Air- tightness of building

The User can select from a pop-up list following options:

- Low – buildings with single window glass panes, without sealing

- Middle – buildings with double window glass panes, with normal air-tightness

- High – buildings with high air- tightness class of windows and doors

Building shielding class

The User can select from a pop-up list following options:

- No shielding – concerns buildings in open space or high buildings in city centres,

- Medium shielding – concerns buildings shielded by trees or by other buildings and in suburbs,

- Big shielding – concerns buildings of average height in city centres, buildings in woods.

w10 (average wind speed on the height of 10 m)

Program will assume the average value of wind speed on the height of 10 m on the basis of climatic data catalogue.

λgr (Ground heat conduction coefficient)

Program assigns a pre-defined type of ground, for which the heat conduction is equal to λgr = 1,2 W/mK. While creating a new project it is necessary to check, if default values concerning thermal features of ground apply for the new project. If the User knows the type of ground, then he should complete this field according to project data. If the calculation option of heat loss according to norm EN 12831 – simplified method has been selected, then calculations of heat loss by the floor on the ground will assume automatically the value λgr = 2 W/mK and this field will not be displayed.

Fields displayed after selecting of option of seasonal energy demand for a building:

QL/ΦL Average daily heat stream generated by a man [W]

An average heat stream generated by a man within 24 hours. It depends on man’s activity and his weight. The field will be completed automatically according to norms for a resting man.

Qcw/Φcw Average daily heat stream generated by warm consumption water per one occupant [W]

An average heat stream generated by warm consumption water, per one occupant within 24 hours. This is a constant value, specified according to norms.

Qme/Φme Average daily heat stream generated by preparing of food per flat [W]

An average heat stream generated by preparing of food per one flat within 24 hours. This is a constant value, specified according to norms.

QeL/ΦeL Average daily heat stream generated by electric devices per flat [W]

An average heat stream generated by electric devices per one flat within 24 hours. Its value depends on number and type of electric devices installed in a flat. This field has been completed with an value recognized as an average value. If a compartment has other gains, the fields is to be completed with actual values.

INW (Obstruction distance from NW direction)

In this field the User will enter the distance of shading obstruction from a building. The obstruction is located in north-west direction.

hNW (Obstruction heigth from NW direction)

In this field the User will enter the height of shading obstruction. The obstruction is located in north-west direction.

Data of shading elements from other orientations towards cardinal points of the compass should be completed analogically, determining their distance and height. These fields are used for shading of building caused by unevenness of ground, presence of other buildings, trees or other topographic elements around the considered building.