Development of new heating systems 

The plastic piping protrudes from the concrete slaps in the test office at the Technical University of Denmark. The construction is intended to resemble as closely as possible a typical office block. Except that there are no radiators to heat it, nor visible ventilation to cool it.

In a new Danish research project, work is in progress on an alternative heating and cooling system based on plastic piping embedded in the concrete slaps. The system can utilise outside air, earth, seawater and groundwater to cool the water in the piping and the concrete slaps at night - which provides cooling for the office next day.

Reducing energy consumption

When the office becomes too warm it emits heat to the ceiling and consequently the temperature drops. The heat is stored in the concrete ceiling. Consequently, system load is levelled out and the peak demand for heating and cooling is reduced. Initial calculations show that compared to traditional heating and cooling systems, the new system is economically competitive in terms of both operation and installation.

In the longer term, it is hoped that the model can show how to reduce energy consumption significantly for cooling, ventilating and heating Danish buildings.

As realistic as possible

"The purpose of these experiments is to learn more about how an integrated cooling system works,” explains Svend Svendsen, professor of building energy and installations at the Technical University of Denmark. “So it has to be as realistic as possible. Therefore we will furnish and fit our ‘office’ with chairs, tables and wooden flooring. Only under well-defined conditions can we achieve a precise cooling effect from night to day and gain an understanding of the real extent of heat emission."

The project comes at a time of growing interest in ways of saving energy. The EU's Building Directive, which comes into effect in 2006, introduces more stringent requirements concerning documentation of the overall energy efficiency of buildings. At the same time, new Danish building regulations are expected to require energy consumption in buildings to be reduced by about 30 per cent.

Attractive alternative

"The new demands mean breaking with traditional thinking and starting to think in terms of new, integrated, competitive energy systems,” says COWI project manager Reto M. Hummelshøj.

"This type of heating and cooling system, which does without conventional cooling and utilises low-temperature heating, could well become a very attractive alternative."

By: Christina Tækker, cht@cowi.com
Published: 25.05.2004