'ENERGY FOUNDATION' technology developed in Austria could offer a sustainable answer to the problem of keeping underground metro systems cool, an invited audience at a London seminar will hear next week.
The technique is based on the casting of high density polyethylene pipes into concrete piles, base slabs or diaphragm walls in contact with the ground, through which is circulated a water/glycol mixture.
This can be used to heat buildings, bridges and underground structures in winter and cool them in summer. Two cut and cover stations on the Vienna Metro extension have already had the system installed, and a similar system in a rail tunnel on the city's outskirts is heating a local school.
Research at the Technical University of Vienna suggests that for every watt of energy needed to operate the system, between 3.5W and 5W is returned as heat energy.
The seminar is being organised by Mott MacDonald. Principal speaker is Professor Dietmar Adam from the Technical University.
'In central Europe there are around 400 energy foundation projects already completed or under construction, ' said Mott MacDonald transport group director Alan Powderham. 'In the UK and the US there are almost none.'