Calculate Heat Load

The heat load calculation according to EN 12831-1 determines the thermal energy requirement for the building and for each individual room. This is how to prepare the planning of the heating surfaces and the selection of the heat generator.

Process description

Building model		Location-specific data

Basic heat load calculation settings

Transfer location-specific data (perform heat load calculation)

Data of the ventilation concept

Design criteria of heat load calculation

Perform calculation

Evaluate calculation

Building model		Location-specific data

Basic heat load calculation settings

Transfer location-specific data (perform heat load calculation)

Data of the ventilation concept

Design criteria of heat load calculation

Perform calculation

Evaluate calculation

Basic heat load calculation settings

The national regulations of the country (in which the building is located), basic technical conditions for the building, and agreements with the client must be taken into account in the calculation and defined as basic settings.

Select: Tools Heat Load Calculation (EN 12831-1 2017). The dialog appears.
Click . The dialog appears: Heat Load Options.

Check settings in

National annex

Selection of the available national appendixes to the applicable standard.

Setting	Effect
EN 12831-1 (Europe)	DDScad calculates using general specifications according to EN 12831-1. Design criteria/Site are defined by manual entry.
DIN TS 12831-1 (Germany)	DDScad calculates using the country-specific specifications for Germany. DDScad first adopts Design criteria/Site from the project properties. You can correct Postal code using a manual entry; DDScad automatically updates the associated values.
ÖNORM H 12831-1 (Austria)	DDScad calculates using the country-specific specifications for Austria. Design criteria/Site are defined by manual entry.

Data from DDScad Ventilation

Setting	Effect
	Parameters for calculating the design ventilation heat loss can be defined only in the Heat load EN 12831-1 function.
	Location-specific data and parameters for calculating the design ventilation heat loss are transferred automatically between the 'Heat load EN 12831-1' function and the 'Ventilation' module. Manual entry of these parameters is blocked in the heat load calculation. Required conditions The project is prepared for this variant.

Building entity minimum temp.

Minimum temperature of the adjacent building entity, which can be maintained, as the case may be, by controlling the room temperature / frost protection.

Setting

Effect

The building does not contain any technical equipment for frost protection. The situation is:

External design temperature;

The building contains technical equipment for frost protection. You can define the value for Building entity minimum temp. .

Increased temperature

Setting for taking into account the parameter in Design criteria (Room), Increased internal temp.(Interior temperature of the heated room (i) under comfort conditions).

Setting

Effect

calculate with internal design temp.

No elevated temperature is to be possible for any room (as compared to the value in Internal design temp.).

No entry can be made in Design criteria (Room), Increased internal temp..

calculate all rooms with increased internal temp.

A globally increased temperature is agreed for each room (as compared to the value in Internal design temp.). Define the global increase in Increase by.

No entry can be made in Design criteria (Room), Increased internal temp..

define increased internal temp. room by room

An individual setting for each room is possible in Design criteria (Room), / Increased internal temp..

Setting	Effect
	For this room, only is valid in Internal design temp.Interior temperature of the heated room (i) under standard conditions.
	Based on the value in Increased internal temp. DDScad calculates an additional amount to be added to the standard heat load of the room .

Include time constant

Setting for using the time constant.

Setting	Effect
	DDScad takes the time constant into account. Depending on the building, a lower heating load may result.
	DDScad does not take the time constant into account. Depending on the building, a higher heating load may result.

Click OK. You can continue with the next step.

Building model		Location-specific data

Basic heat load calculation settings

Transfer location-specific data (perform heat load calculation)

Data of the ventilation concept

Design criteria of heat load calculation

Perform calculation

Evaluate calculation

Design criteria of heat load calculation

Background

A heat load calculation requires a large number of inputs and definitions at all structural levels. DDScad simplifies this process by offering the following options:

Inheritance
Individual setting of several rooms/components in one step

Relationships in the dialog

Inheritance

Individual setting of several rooms/components in one step

Relationships in the dialog

Inheritance

Individual setting of several rooms/components in one step

For the respective marked entry in Level structure, DDScad displays the configurable parameters in Design criteria

Relationships in the dialog

Inheritance

Individual setting of several rooms/components in one step

Inheritance

Automatic transfer of properties from a parent class to several subordinates. The connection between the levels remains intact. But it can be disconnected and restored. The chart shows the flow of data using the example of the value Min. air change.

Define a general design criterion for all rooms at the structure level "Building".
Define a design criterion for subordinate rooms of this building entity at the structure level "Building Entity".
In a single room, define an individual value.

Simulation in the chart:

Click in the field: creates an individual value for this level.
Clicking on reactivates the adoption from the parent level

Building: defines general design criteria

Min. air change

0,5 1/h

Building Entity 1

0,5 1/h

indicates acceptance, click

in the field for input

Room 1.1

0,5 1/h

indicates acceptance, click

in the field for input

Room 1.2

0,5 1/h

indicates acceptance, click

in the field for input

Building Entity 2

0,5 1/h

indicates acceptance, click

in the field for input

Room 2.1

0,5 1/h

indicates acceptance, click

in the field for input

Room 2.2

0,5 1/h

indicates acceptance, click

in the field for input

Relationships in the dialog

Inheritance

Individual setting of several rooms/components in one step

Despite the inheritance of values, you must define individual settings for individual rooms. You can complete this task quickly using a systematic procedure. We recommend the following approach:

In Level structure select "Building" or "Building Entity" DDScad displays the rooms and building components contained there in a list .

Despite the inheritance of values, you must define individual settings for individual rooms. You can complete this task quickly using a systematic procedure. We recommend the following approach:

Select the entries which are to be given the same individual settings (e.g. all entries Room Text Properties="Kitchen").