Variant Comparison

Here, the results of the individual variants in the project can be compared. For this purpose, at least one variant must be created additionally to the main project. 

In the variant selection, there  are  several different tabs displayed. In the ETU-Simulation, which tabs are displayed depends on the selection of the project options. In the individual separately available programs the tabs are predefined. 

Building Simulation

In the Building Simulation tab, the results of the building simulation of the individual variants are compared with each other. The maximum heating and cooling loads as well as the sum of heating and cooling energy requirements per year are shown in tabular form.

Below this, the heat gains and losses summed up over the year are shown as bar charts. The source of the gains and losses is shown in different colors. 

Possible sources of heat gains are:

Building components: this is transmission of heat from outside into the building.
Appliances: electrical or other appliances that produce and emit heat
Heating: heat emitted from the heating system into the building
Lighting: heat emitted by lighting
People: heat emitted by people
Solar: heat gains from solar radiation
Ventilation: heat gains through ventilation in case the outdoor temperatures are higher than the temperature of the ventilated rooms.

Possible sources of heat losses are

Building components: This is the transmission of heat through the building components to the outside.
Cooling system: the amount of heat dissipated by the cooling system
Ventilation: Heat losses due to ventilation

When the mouse is moved over a single bar, the distribution of this bar is displayed as a pie chart. This applies to all bar charts in the variant comparison.

Summer heat protection

here the number of overtemperature degree hours of the rooms of the individual variants are compared with each other. The most unfavorable room is shown as one section of the bars and the sum of all other rooms is shown in the second section of the bars. 

Plant simulation

Here, the heating and cooling requirements of the building are shown in tabular form in the individual variants. 

Below this, heat and cold generation by the systems are shown as bar charts. It is easy to see from the individual areas of the bar charts which part of the heat demand is covered by which system component. In the example, the heat is generated by a boiler in the original project, by a combined heat and power plant in the "extension and CHP" variant, and by a heat pump combined with a heating rod in the "insulation, HP and PV" variant.

An analogous approach is taken for existing cooling generators. Here, the cooling generation is shown as negative columns.

If there is no cooling or heating generation in a project, no column is shown.

Electricity

Here, the electricity generation, electricity demand and electricity demand coverage of the individual variants are compared. If no electricity is generated by PV systems or CHPs, the corresponding bar is not shown. 

For the electricity demand, the household electricity and the electricity demand by the plant, if any, is shown. Auxiliary energy is not included here.

The electricity demand coverage bars show the sources from which the total electricity demand is covered. In many projects this will be mainly from the grid. If a PV system or CHP is present, parts of the electricity demand will also be covered either directly by own use or via a battery, previously charged by the CHP or PV system. 

Profitability

Here, the economic efficiency of the individual measures is compared. The investment sum, as well as the amortization period, the return and the net present values are shown in tabular form. The annuities of the respective variants are also compared, both in tabular and graphical form.