Energy Saving Activities in the City of Helsinki

Panel: Panel 2: Incentives and instruments to achive greater

Authors:
Risto Kosonen, VTT Building Technology
Ulla Soitinaho, Helsinki Energy Management Agency

Abstract

There is potential to save energy economically and also improve the function of ventilation. Energy auditing is an efficient tool for clarifying the potential.

In 1993 the City of Helsinki made an agreement with the Ministry of Trade and Industry on objectives and measures for energy saving in the building stock owned by the City of Helsinki. For that target the City of Helsinki has carried out studies concerning energy use in multi-storey residential buildings and offices. These studies indicate that there is potential to improve the energy economy and the function of ventilation in individual buildings.

Energy auditing is an efficient tool for clarifying the energy balance and energy-saving potential and in some cases identifying buildings with inadequate ventilation. So far the City of Helsinki has carried out the energy audits in 98 buildings. The types of these buildings were, for example, schools, day nurseries, hospitals and offices. The results show that the potential savings for buildings would be, on average, 17 % in heating energy, 9 % in electricity and 7 % in water consumption.

The required investment would be paid back in 1,5 years. The pay-back period is rather short because most of these measures do not require any investment, e.g. changing the operation time of the air-handling unit or set points is only required. Improving the operation of the air-handling unit is most effective because only a one hour reduction in the daily operation time of fans means about 5 % energy saving in a typical office building. Energy-saving investments which were found to be economical were, e.g. heat recovery of exhaust air, control system and water tap.