Helsinki zones in on leaky office

Background

Built in 1958, this office building was subject to from highly irregular heat distribution, including over-heating, largely as a result of the leaky windows in other areas. In an attempt to reduce the draftiness of the building, the ventilation system was over pressurised, and ran for every hour of the year.

Building details
Type of building:	Office block
Year of construction/ Floor area/ Operating hours:	1958/ 5,368 m2; 15,833m3 / 7am – 6pm
Heating and cooling / measures installed	District-connected central heating, no cooling needed.
Energy label/CO2 emissions	District heating 1993: 1026MWh (64.8 kWh/building m3) 2005:544 MWh (34.4 kWh/building m3) Savings amounting to 47%  Electricity 1993:471 MWh (29.8 kWh/building m3) 2005:376 MWh (23.7 kWh/building m3) Savings amounting to 20%  Water 1993:1519 m3 (95 l/building m3) 2005:1635 m3 (103 l/building m3) A decrease of the performance by 8%  In 1993 (before the energy audit) the Display classification was: Energy consumption E CO2 emissions D Water consumption C  In 2005 the Display classification was: Energy consumption C CO2 emissions C Water consumption C

ProjectDescription
Aim	The project was based on the voluntary energy conservation agreement between the City of Helsinki and the Ministry of Trade and Industry. The agreement sets quantitative and qualitative targets for energy management in municipal operations. One of the targets is to carry out energy audits in 80 % of buildings owned by the City, and then implement the measures suggested.
Key points	From the recommendations suggested in the energy audit of Vironkatu 2, the following action was taken:  All windows were renovated at least to the extent that they could be sealed and secured  The ventilation operating hours were reduced to conform to occupancy and the incoming air pressure. Inside temperature was also reduced, as a result of the window improvements. As the building was now less draughty, the previously installed Thermostatic Radiator Valves (TRVs) also became far more effective  Sensors were installed in corridors so that they only be lit when needed  Heating and electricity were switched to cheaper tariffs (costs savings only) Although all of the changes were technical, the City of Helsinki, PWD Construction Management/ Life Cycle Services responsible for carrying out the improvements felt that the occupants of the building have become far more energy conscious, as a result possibly leading to further savings.
Reason for inclusion as Shining Example	To show that with minor measures and costs relatively high savings can be achieved.  In 1993 (before energy audit) the Display classification was: Energy consumption E CO2 emissions D Water consumption C  In 2005 the Display classification was: Energy consumption C CO2 emissions C Water consumption C

Costs&Benefits
Costs & funding	The energy audit was financed by the yearly grant in City’s budget dedicated to improving energy efficiency in all municipal buildings in Helsinki. Energy Audits are subsidized (50 %) by the Ministry of Trade and Industry.The improvements in this project were financed by the user (Department of the City of Helsinki). Usually improvements are financed by the yearly grant in City’s budget dedicated especially to energy efficiency measures in municipal service buildings.
Benefits	The following benefits have been obtained:  District heating 1993: 1026MWh (64.8 kWh/building m3) 2005:544 MWh (34.4 kWh/building m3) Savings amounting to 47%  Electricity 1993:471 MWh (29.8 kWh/building m3) 2005:376 MWh (23.7 kWh/building m3) Savings amounting to 20% Yearly savings 24,000 euros.

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