Global temperatures are rising and this is already affecting building designs in the Danish construction industry. For the design of the HVAC systems rising temperatures will mean smaller heat losses in winter and higher heat gains in the summer.

A global temperature rise of e.g. 2 °C will affect the energy needed to cool a space in summer negatively. If the temperature rises 1 °C the effect will be less so, but more so if the temperature rises 5 °C. The golden question therefore is: “How much can temperatures rise before my office needs to have its HVAC systems upgraded?”

To give the best answer a dynamic thermal simulation must be run and analysed.

Unfortunately, most computer programmes for thermal simulation do not include options to vary the external temperatures but offers only choices of historical weather data.

One exception to this is the programme package Virtual Environment from IES Ltd. which Ramboll has been using since January 2008.

In IES-VE historical temperatures for external air can be offset by any positive or negative value and results from different simulations can easily be compared – both with the relation to internal room temperatures and comfort parameters such as PMV. This means that the correct answer to the golden question is now only a simulation away.

As the first consultancy engineers in Scandinavia Ramboll has fully incorporated IES-VE as our general simulation tool.

The advantages and new possibilities of IES-VE are numerous e.g.:

• Full 3D modelling of simulation models
• Better analysis of concept building designs
• Complete modelling of the surroundings
• Detailed calculations of the shading of buildings (can also be animated)
• Simulation with customized HVAC plants
• Output results which include
  • Comfort parameters such as PMV and PPD (%)
  • CO2 levels in rooms (ppm)
  • Daylight factors (%)
  • Green house gas emissions (kgCO2)