High Performing Buildings - Fall 2011 - (Page 13)

d o u b l e fa ç a d e : w i n T e r throughout the volume of the space, which is then drawn into the raised floor plenum at each of the six floors connected to the winter garden. Displacement ventilation is used to efficiently and effectively distribute fresh air. An “air highway” directs fresh air under the raised floor from south to north along the office lofts. The air, slightly cooler than space temperature, spills out of floor level vents to flood the office space. Stale air is naturally drawn towards the north end of the office, driven by buoyancy forces and the pull of the solar chimney. The solar chimney passively exhausts the air in the summer. In the winter, fans at the base of the solar chimney draw exhaust air down to both ventilate the parking garage and recover exhaust heat. The interstitial space in the double façade quickly heats up due to solar gains — especially in the winter. During a typical week of –25°C outdoor temperatures (green line), the façade around the building is heated to 20°C (blue line) on sunny days (red line). Thermal Comfort Heating and cooling is achieved primarily through the use of active radiant slabs. More than 180 miles of plastic tubing is embedded in the concrete, and slab temperatures are modulated between 20°C and 23°C (68°F and 73°F) to maintain comfort throughout the year. The thermal mass of the all-concrete building also minimizes temperature fluctuations throughout the occupied hours, and allows heating and cooling systems to be turned off on evenings and weekends. The passive design features combined with the efficient heating supply system, including a groundsource heat pump, exhaust air heat recovery, and condensing boilers, reduce energy use for heating to only 28 kWh/m² (3 kWh/ft2) annually. This is a significant drop from an annual typical heating load of 250 kWh/m² PerForming Buildings 13 lighT level marCh 2011 Integrated daylight sensors help reduce office lighting energy use. Even on an overcast day with minimal brightness, lighting energy (red line) quickly decreases as daylight (blue line) increases. Fa l l 2 0 1 1 HigH

Table of Contents for the Digital Edition of High Performing Buildings - Fall 2011

High Performing Buildings - Fall 2011
Commentary
Contents
Manitoba Hydro Place
Maplewood Police and Court Building
Omega Center for Sustainable Living
Dockside Synergy at Dockside Green
Golden Hill Office Center
Letters to the Editor
Products
Advertisers Index

High Performing Buildings - Fall 2011