EbeneAllgemein-WannWelcheSimulation/en

Aus IBPSA-Germany

When to use which simulation type ?

Inhaltsverzeichnis 1 Background 2 Yearly energy consumption --> plant simulation 3 Overheating and undercooling/averaged thermal comfort --> zonal, thermal simulation 4 Window ventilation and air quality --> zonal air flow simulation (air flow network) 5 draught effects and local thermal comfort --> high resolving CFD-simulations 6 Glaring, daylighting, daylight autonomy --> daylight simulations 7 Analysis of shadowing 8 more

Background

First of all it must be pointed out that different questions during building design - especially of sustainable buildings with high performance - definitely require different simulation types or methods. A "super-simulation," which is able to answer all questions during the design process, does not exist - at least not yet and not in the near future.

An overview about typical topics during the design process and the appropriate simulation types are listed below.

Yearly energy consumption --> plant simulation

The current climate change, which can not be disbelieved any longer and which is manifested by the newest IPCC report in 2007, makes the performance of a building more and more important. Therefore the energy consumption of a building, which will be necessary for operation in future, shows an increasing significance ot i´t's design. The yearly energy consumption has become an essential building property, whose relevance precipitates in the new energy certifcates (e.g. LEED, Green Building, Green Star, ... ?). For this Background it has become important to predict the building's future energy consumption by simulation.

The caclulated yearly energy consumption of a non-residential building consists of several parts, which originates from the relevant technical plant:

• The simulation of heating system provides the yearly heat energy consumption of the building.
• The simulation of the air-conditioning resp. the air-handling-unit (ahu) provides the energy consumption for a complete year, which is necessary for pre-heating and pre-cooling of the supply air; this simulation also provides the energy, which is necessary for the transport of the air through the building (from air inlet, through ahu into the building's rooms, exhaust air out of the rooms and through heat recovery towards outside).
• The simulation of cooling system (if existent) delivers the building's yearly cooling energy.
• The simulation of artificial lighting provides the yearly electrical energy consumption for lighting systems.

The building's energy consumption for a complete year has been estimated by very rough approximations in the past (and still today), because more accurate methods have not been available - and this rough approach was less work.

But nowadays simulation tools are available, which are able to predict the building's yearly energy consumption quite well. As the role of energy consumption is becoming more and more important, it must be predicted for each building specifically in a reliable and accurate way: These requirements can be satisfied only by a dynamic plant-simulation with boundary conditions, which are varying with time.

Overheating and undercooling/averaged thermal comfort --> zonal, thermal simulation

Window ventilation and air quality --> zonal air flow simulation (air flow network)

draught effects and local thermal comfort --> high resolving CFD-simulations

Glaring, daylighting, daylight autonomy --> daylight simulations

Analysis of shadowing

more

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