Energy in Focus Energy Savings with Water Based Systems By Maija Virta Specialist of Indoor Environment Technology

Energy in Focus

Annual energy consumption of the systems Heating (kWh/m 2 ) Cooling (kWh/m 2 ) Fan electricity (kWh/m 2 ) TOTAL (kWh/m 2 ) Fan coil (dry) Chilled beam VAV Chilled beams in offices, VAV in meeting rooms

Energy in Focus From Office to Meeting Room

Energy in Focus Case Study of an Office Building in Paris Open landscape offices Office rooms Meeting rooms Office rooms Open landscape offices 10 floors m 2 total area m 3 total volume Landscape office 74 % Office rooms 26 % Meeting rooms 15 % Other 8 %

Energy in Focus Summary of Building and System Design Envelope Exterior wall U-value 0,3 W/m 2 K Window U-value 1,1 W/m 2 K (Arctic blue), 1200 mm x 1800 mm in 1.35 m module Window area / Floor area in exterior offices = 25 % Solar loads Total solar transmittance 0,31(Arctic blue), target level is SW 65 W/m 2 / NE 55 W/m 2 External shading by an overhang of 500 mm located 200 mm above the window Air handling units Dedicated outdoor air system with heat recovery by a plate exchanger (n=60 %) Air handling unit sizing with low face velocity (SFP 1, 6 kW/m3/s) Fan pressure gain control Filtration efficiency EU 3 + EU 8 supply. Exhaust air filtration ; class EU3 Supply air temperature control using outdoor air temperature compensation. Chiller plantCommon chiller with air cooled condenser for air handling units and chilled beams Boiler plantCondensing gas boiler DuctworkVariable airflow and constant pressure in zones Pipe work4 –pipe hydronic system Room air conditioning Adaptable, active chilled beams for both cooling and heating Ventilation using constant airflow in offices, demand based ventilation in meeting rooms Occupancy control for temperature control comprising set point shift

Energy in Focus Chilled Beam System Dedicated outdoor air system with heat recovery from exhaust air Ventilation using constant airflow in offices and in meeting/team/project rooms Room temperature control Active chilled beams for both cooling and heating One chiller with air-cooled condensers. Gas boiler plant

Energy in Focus LoadCapacityAir flow rate Occupancy Offices Occupancy Landscape offices Occupancy Meeting rooms W/m 2 ACHm 2 / pers Lighting, offices & meeting rooms12 Occupancy10152 Equipment20 W / m 2 15 W / m 2 30 W / m 2 Infiltration; Winter/Summer0,25 Continuous exhaust ventilation0,1 Internal loads

Energy in Focus Results: Total Delivered Energy Consumption

Energy in Focus Total Energy Consumption

Energy in Focus Delivered and Primary Energy Consumption Delivered energy 77,7 kWh/m 2,a HVAC + lights: 48,9 kWh/m 2,a Primary energy 175,4 kWh/m 2,a (Primary energy factors: Gas 1, Electricity 2,5) HVAC + lights: 125,9 kWh/m 2,a

Energy in Focus Improved Annual Primary Energy Efficiency: 126 kWh/m 2 => 50 kWh/m 2 => 0 kWh/m 2 ??? 1. Lighting (74 kWh/m 2 ): Efficiency 12 -> 9 -> 6 W/m2 Control (occupancy, day light) Utilisation of day light 2. Ventilation (39 kWh/m 2 ): Demand based ventilation in offices Reduced primary air volume (very low polluting materials) Chiller COP Hybrid ventilation Improved heat-recovery Free cooling of water 3. Energy production Low and zero carbon energy sources Better insulation?