Graphics: DTU

About Annex 68


To achieve nearly net zero energy use, all buildings in future will need to be more efficient and optimized. As new buildings are already well insulated in certain industrialised countries, the focus is shifting to limiting space heating energy consumption by reducing ventilation demand. Low energy buildings need to be airtight and energy demand for ventilation is often reduced by lowering the ventilation rate to the minimum necessary. Each of these can have adverse impacts on indoor air quality (IAQ). This project is therefore investigating how to ensure that future low energy buildings are able both to improve their energy performance and to provide comfortable and healthy indoor environments.

Reducing the amount of fresh air supplied to a building would save energy, but however may increase the risk of poor indoor air quality. Therefore, it is very important to find the ideal balance between energy efficiency and the need for ventilation. The aim of this project is to use existing data and tools, which in combination give an integrated picture of the air flow, hygrothermal and air quality conditions in whole buildings with a focus on optimisation of their use and operation. This should achieve energy efficiency alongside providing healthy and comfortable indoor environments.

Project Objectives

The two main objectives for the project are:

  1. To provide a scientific basis for the design and operational strategies of buildings that have minimal energy consumption, and at the same time maintain very high standards regarding indoor environmental quality based on the control of sources, sinks and flows of heat, air, moisture, and pollutants under in-use conditions.
  2. To collect and provide data about properties for transport, retention and emission of chemical substances in new and recycled materials under the influence of heat and moisture transfer.

Planned Deliverables

The planned deliverables from this project are:

Definitions of IAQ performance metrics.

Mechanistic emission source and sink models to estimate pollution loads under realistic environmental conditions.

A database of material storage and transport properties, as well as pollution loads in existing buildings.

A modelling framework and design tool for integrated and coordinated design of low energy and high IAQ buildings.

A guidebook on operational strategies for optimal energy performance and good IAQ in residential buildings.

A report presenting and analyzing residential green buildings that achieve optimal energy and IAQ conditions under various climatic situations.

Recommendations for regulatory authorities and guidelines for occupants and building operators.


Project Beneficiaries

The mail project beneficiaries will be:

  • Building designers (engineers and architects),
  • Manufacturers of building materials and services systems,
  • Regulatory authorities who stipulate required ventilation and energy performance requirements
  • Operators and users of buildings.
24 JUNE 2024