thermal modelling... a design tool


The current design/building process can be described as follows:

In this example, thermal modelling is only being used as an adjunct to the building approval process

This approach may bring about some delays if rework of drawings and further energy assessments are required.

This is no different to designing a home without any cost planning. We use to think that we could design a home within budget, now we use a builder or quantity surveyor to give us some cost advice.

A more appropriate approach to the process today would be as follows:

Building thermal modelling tools, such as FirstRate, AccuRate and BersPro, handles the physics- climate data, solar geometry/solar radiation, building materials (heat transfer) and fluid dynamics (air flow) to calculate the internal temperatures and the energy required to be pumped in or removed to achieve the required comfort level in the home.

When designing and building for thermal comfort you need to control the heat flow and the air flow. Heat flow is managed using insulation, thermal mass, floor to ground contact, summer shading, glazing and thermal bridges. Air flow is managed using draught proofing, cross ventilation, ceiling fans and thermal venting.

These simulation tools can also test the impact of different design decisions, and carry out “what if” scenarios, explore the impacts of different material choices.

By using these tools during the design process, you can:

-  Optimise building thermal performance

–  test the impact of design choices

–  test the impact of materials selection

–  assist in getting the most benefit for least cost

-  reduce rework

-  assist in modification of designs to achieve high performance in different climates/lot orientations

-  assist in client education/communication

-  achieve greater client satisfaction

Elly Joel