High Performing Buildings - Fall 2011 - (Page 15)

LeSSonS LeArneD office Acoustics manitoba Hydro Place shows that energy efficiency can be complimentary to a highquality indoor environment. For example, the glass double façade is critical to the energy concept for the building, but also offers occupants good daylighting, access to views and personal control of natural ventilation. However, the abundant glazing, in combination with the exposed concrete ceilings, results in many hard surfaces. These hard surfaces create an acoustical environment different from traditional offices, which often feature ceiling tiles. Accordingly, some occupants were initially concerned about speech privacy and acoustical quality. A sound-masking system installed within the raised floor has proven beneficial—the white noise generated mimics HVAC noise and provides aural distraction to employees. in addition, acoustically private meeting rooms were added on each floor. in general, though, employees have adapted to a quieter environment, and communicate in a manner suitable to the environment. Commissioning Challenges unique commissioning challenges are associated with a building that responds to the climate. The biodynamic nature of manitoba Hydro Place means that the building responds very differently to Winnipeg’s four distinct seasons. As such, there are building sequences that only can be tested during a brief seasonal window once a year. An entire year may be required for system commissioning. The lighting system proved to be the most difficult system for commissioning. The office lighting system, while elegant in its form and functional as an energy-saving device, provides little feedback to building operators. All other building components provide a wealth of real-time information that can be used to troubleshoot problems and optimize sequences. The lighting system, however, only allows one-way communication to the device. ideally, future generations of integrated lighting systems will include feedback from the daylight sensor of each fixture, real-time energy data and other information. Double Façade in a Cold Climate manitoba Hydro Place is among the first large-scale implementations of a double façade in a cold climate. This is a technology still viewed largely with a degree of skepticism in north America. The double façade at manitoba Hydro Place was studied extensively prior to implementation, using computational fluid dynamics, several mock-ups and many thermal models. The analysis led to several unique characteristics of the façade. most notably, the single glazing is located on the inside, a departure from nearly all other implementations. This was a result of concerns about frost formation in the winter. To account for summer conditions, the single inner glazing has an exposed pyrolytic low-e coating to minimize radiant effects. optimization Stage manitoba Hydro is committed to ongoing study and optimization of manitoba Hydro Place. since occupancy and the end of the commissioning phase, building sequences and setpoints have been regularly updated. examples of the more significant sequence changes from the original design include: • ncorporating outdoor humidity into the I natural ventilation sequence to ensure that the building enters dehumidification when appropriate. • odify geothermal field pumps to M control speed as a function of return temperature from the field (instead of a pressure setting). • ncrease radiant slab zoning resolution to I reflect different solar gains at north and south tips of the office tower. • se low temperature heating water supU plied by the ground-source heat pump to displace the high temperature system from the condensing boilers in the shoulder seasons. BuiLDing teAM Client manitoba Hydro Architects Kuwabara Payne mcKenna Blumberg Architects (design architects), smith Carter Architects and engineers (executive architects), Prairie Architects (advocate architect) energy and Climate Transsolar energietechnik gmbH Contractor PCl Constructors Canada structural engineer Crosier Kilgour/Halcrow Yolles mechanical & electrical engineer earth Tech Canada lighting design Pivotal lighting design landscape design Hilderman Thomas Frank Cram, Phillips Farevaag smallenberg (23 kWh/ft2) in Winnipeg where heating degree days are typically above 10,000 (base 65°F). Daylight Autonomy A narrow (11.5 m [38 ft] wide) loft combined with a 3.1 m (10 ft) ceiling height and open floor plan provides natural daylight throughout nearly all of the occupied areas. The double façade design is “stepped” to maintain a good daylighting angle, and low-iron glass provides excellent visible transmittance. T5 high output fixtures supplement the daylight through uplighting, and the use of an integrated daylight sensor. Fa l l 2 0 1 1 HigH For common areas, feature lighting is programmed based on outdoor light levels. Currently, the lighting energy is reduced by 44% from the MNECB reference building. This is expected to drop further as recent sequence changes tying exterior and common area architectural lighting to outdoor light sensors are reflected in metered data. Building Management System (BMS) The building management system (BMS) uses prevailing conditions (temperatures, radiation, wind, precipitation) for real-time integration of PerForming Buildings 15

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