Design and Operational Strategies for High IAQ in Low Energy Buildings

Overview

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 use 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 has therefore investigated 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. This project has used 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 achieves energy efficiency alongside providing healthy and comfortable indoor environments.

The project has achieved the following:

• provided a scientific basis for the design and operational strategies of buildings that have minimal energy use, 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,
• collected and provided data about properties for transport, retention and emission of chemical substances in new and recycled materials under the influence of heat and moisture transfer.

The project beneficiaries are:

• building designers (engineers and architects),
• manufacturers of building materials and services systems,
• regulatory authorities who stipulate required ventilation and energy performance requirements, and
• operators and users of buildings.