Acronym | AdVent Case 9
Posting Date | 25 November 2009
Country | Finland
Theme | Thermal comfort, indoor air quality, acoustics, Controls, energy management systems, Building envelope (walls, windows,...), Energy efficiency technologies and materials, General, Very low energy buildings, Air conditioning, cooling, ventilation, air infiltration
Abstract | The building has an air-conditioning system with mechanical supply and exhaust ventilation and
chilled beams. The building is connected to Turku area district heating and district cooling distribution
systems. The temperature of water in the district heating main varies between 65°C and
115°C for the supply and between 40°C and 60°C for the return water, depending on the heat demand.
In the district cooling network the delivery temperature is +7°C and the return temperature
+17°C. District cooling water is produced with free cooling (outdoor air) and compressor technology.
All the heating and cooling systems in the building are connected indirectly to the district networks through heat exchangers. Heat extracted from the district heating network is used in the building for domestic hot water and space heating through central air handling units and hot water radiators. The district cooling water system
serves both the central air handling units and chilled beam units installed in the open-plan and
cellular office spaces. The chilled beam units have integrated, control equipment, supply air
cooling heat exchangers, fluorescent lighting and a communication link to building management system
(BMS). Outside normal office hours, the BMS sets lights in the units by default to ¼ power and lighting
demand is controlled by IR motion-sensors. Ventilation and air conditioning strategy: The building is divided into five ventilation zones.
Description | YIT Office Building is a typical modern five-storey office building and was completed in October
2005. The ground floor (900 m²) serves as a workshop and storage facility and the remaining four
floors (6 000 m²) have both open-plan and cellular office spaces. There is a large glass roofed
atrium in the centre of the building extending from the first floor to the roof. In the lower part of
the atrium (at the second floor) there is a cafeteria and a small kitchen (the second floor partly covers the atrium). A total net floor area of the building is 6 906 m² with a total volume of 34 000 m³.
Lessons learnt | In a cold climate heating of the ventilation air is the most significant heat loss especially in the
non-residential buildings. To achieve adequate energy performance of the building, the use of
controlled ventilation rates and heat recovery is essential in a cold climate. For that reason natural
ventilation systems with high ventilation rates and no heat recovery cannot be used in a cold
climate. Energy performance of described ventilation system is achieved through effective heat recovery in
the air handling unit. Another benefit is low specific fan power (electricity use of the ventilation
system) due to relatively low ventilation rates. As ventilation rates are based only on the ventilation
need caused by human occupancy, they are significantly lower compared to all-air systems where
ventilation rates are based on cooling or heating need. To achieve low specific fan power, low pressure
design of ductwork and demand controlled ventilation control in meeting rooms are used.
Case Languages | English