Ventilative Cooling

Overview

The current trend in building energy efficiency towards nearly zero enrgy buildings creates a number of new challenges for building design and construction. One of the major challenges is the increased need for cooling in highly insulated and airtight buildings, which is not only required in summer and midseason periods, but can also be needed in winter, particularly in office buildings. Ventilative cooling is the application of ventilation air flow to reduce the cooling loads in buildings. It utilizes the cooling and thermal perception potential of outdoor air. Ventilative cooling can be an attractive and energy efficient solution to reduce the cooling load and avoid overheating of both new and renovated buildings. (Before ventilative cooling is considered, internal gains from equipment and solar radiation are assumed to be reduced to a reasonable level.)

Ventilation is already present in buildings through mechanical and/or natural systems. It can remove both excess heat gains, as well as increase air velocities and thereby widen the thermal comfort range. As cooling also becomes necessary outside the summer period, the possibilities of using the cooling potential of low temperature outdoor air increases considerably. To address the cooling challenges of buildings the project research will focus on:

• Development of design methods and compliance tools related to predicting, evaluating and eliminating the cooling need and the risk of overheating in buildings
• To develop new attractive energy efficient ventilative cooling solutions

Project objectives

• Analyse, develop and evaluate suitable design methods and tools for prediction of cooling need, ventilative cooling performance and risk of overheating in buildings
• Give guidelines for integration of ventilative cooling in energy performance calculation methods and regulations, including specification and verification of key performance indicators
• Extend the boundaries of existing ventilation solutions and their control strategies and to develop recommendations for flexible and reliable ventilative cooling solutions that can create comfortable conditions under a wide range of climatic conditions
• Demonstrate the performance of ventilative cooling solutions through analysis and evaluation of well-documented case studies