17.0 VENTILATION We took into consideration the design of window sill and window height so that the users are still able to reach across desk and open the windows in order to adjust their thermal comfort. We want them to interact more with the building. Brian Gasmena, Architect, Perkins + Will LESSONS LEARNED Resolve interior layouts with ventilation strategy Coordinate services in the raised access floor spaces Facilitate inhabitant interaction with the building systems Balance acoustic privacy and ventilation Operable vents at the top of the atrium 1.0 Executive Summary 2.0 Project Background & Overview Intake for the mechanical ventilation system The central atrium acts as a thermal chimney that drives natural ventilation flow in the building The narrow floorplates assist cross-ventilation flows Displacement ventilation through the Under Floor Air Distribution system 3.0. Vision & Leadership 4.0. Goals & Targets 5.0. Partnerships 6.0. Research 7.0. Building Design 8.0. Design Process 9.0. Structural System & Wood 10.0. Building Materials 11.0. Energy Systems 12.0. Rainwater System 13.0. Reclaimed Water System 14.0. Landscape & Site 15.0. Living Roof & Living Wall 16.0. Lighting 17.0. Ventilation Image 17.1 Ventilation Diagram 17.1 Systems Overview Ventilation at CIRS is provided through a mixed mode system. The building is designed to utilize passive natural ventilation strategies in most of the regularly inhabited spaces. Operable windows allow for the personal adjustment of air flow and temperature in workspaces. Cross-ventilation is designed to move air through the smaller spaces while the atrium draws air from the rest of the building through the stack effect and exhausts it through vents on the roof. Mechanical ventilation is provided by two air handling units (AHU 1 and AHU 2) that supply fresh filtered air to the building. One unit is dedicated to the large Auditorium and the other serves the rest of the building. The Auditorium receives filtered air, both heated and cooled, by means of displacement ventilation from diffusers located underneath the seats. In smaller spaces, mechanical ventilation supplements natural ventilation and is heated only. The air is supplied through a displacement ventilation system underneath the raised access floor. Inhabitants can adjust localized vents to control the airflow in their personal space. 17.1 Overview 17.2 Description 17.3 Campus Context 17.4 Goals & Targets 17.5 Benefits 17.6 Challenges 17.7 Lessons Learned 18.0. Building Rating Systems FUTURE SECTIONS TO BE ADDED: 19.0. Monitoring & Measurement 20.0. Construction 21.0. Commissioning & Performance Testing 22.0. Inhabitants vs. Occupants 23.0. Community (food...) 24.0. Operations & Maintenance 25.0. Continual Evaluations 1
CIRS TECHNICAL MANUAL AGENTS Architects: Perkins + Will Mechanical Engineers: Stantec Image 17.2 Cross Ventilation Image 17.3 Diffusers 17.2 System Description Office Blocks The office blocks have manually operable windows that allow the internal spaces to be naturally ventilated. Inhabitant control over airflow and temperature through mechanical ventilation in personal spaces is also provided. There are two levels of operable window, one at desk height and one at the clerestory level. The original design included an automated control system for the clerestory windows, but it was removed to save on cost and long-term maintenance issues. Pole cranks are provided to allow inhabitants to open the clerestory windows manually. A displacement system ventilates the office blocks through an under floor air distribution system, with floor vents along the exterior walls. Building operators set the rate, flow and air temperature and manual diffusers at each vent allow inhabitants to control air flow in personal spaces. The automated building management system monitors the windows, and when 30 per cent or more in a space are open, mechanical ventilation to that zone is turned off. Inhabitants can request lower or higher temperatures through an interface with the Building Management System. The narrow design of the office blocks was intended to facilitate cross-ventilation between the glazed north and south façades, through a mix of open and closed offices. As the spaces were fit out for tenants however, the amount of closed offices significantly increased, reducing the effectiveness of the cross-ventilation strategy. A gap above the interior partitions at the height of the beams will allow some air flow to move through the space and the operable windows will still provide fresh air and temperature control for the office inhabitants. 2
Auditorium Ventilation in the Auditorium is supplied exclusively by displacement ventilation air via a dedicated air handling unit. Airflow and temperature are controlled by building operators through pre-set settings. Warm air is exhausted from the theatre into the atrium, then leaves the building through vents at the top of the atrium. Atrium Ventilation in the atrium is supplied naturally by drawing air from the rest of the building through the stack effect. Air is exhausted through motorized vents in the roof, functioning as a passive cooling tower. Manually operable windows adjacent to the social spaces on the upper floors allow inhabitants to control the airflow and temperature in their immediate environments. Service Spaces The services spaces of the building are mechanically ventilated. Heat from the exhaust air and the mechanical equipment is captured by a waste heat recovery system and used to pre-heat fresh air brought into the building. PROCESS Design process: Ventilation strategies were part of the dedicated energy charrette and were developed during the integrated design process. Construction: Passive strategies and mechanical systems were constructed as part of the base building. Commissioning: Operations: UBC Building Operations will oversee the mechanical ventilation systems and the operable components of the passive strategies. Inhabitants have the ability to control both the passive strategies and the mechanical systems in their local environments. Image 17.4 Construction photo of the installation of building systems in the raised access floor plenum. 3
CIRS TECHNICAL MANUAL COSTS Costs will be added in a future update 17.3 Campus Context UBC Campus Plan The UBC Campus plan considers ventilation for new buildings to be an important aspect of the integrated approach to energy planning. On a building scale, new projects are expected to incorporate strategies that reduce energy demand and carbon emissions, such as the use of natural ventilation at CIRS. UBC Campus Plan, Part 2 Campus Plan Section 6.2 Sustainability Practices (pg 38-39) UBC Design Guidelines The UBC Campus Plan Design Guidelines outline design suggestions, such as passive design strategies, to be considered early in the design process to improve energy performance and building comfort. Passive ventilation is considered vital to reduce energy use and improve inhabitant comfort. The Design Guidelines state that new buildings should be designed to use the surrounding naturally occurring air flow patterns to facilitate passive ventilation. This can be achieved through shape to maximize the effectiveness of these flows in providing fresh air to building occupants. UBC Design Guidelines 2.3.10 (a ii) Projects are also urged to incorporate operable windows for natural ventilation and consider internal layout, building size, stack effect and orientation to prevailing winds. UBC Design Guidelines 2.3.10 (e iv) UBC wishes to enhance the comfort and wellbeing for inhabitants through provision of a steady flow of fresh air. New projects are must consider the location of air exhaust and intake in relation to air quality, natural ventilation, and energy use. UBC Design Guidelines 2.3.10 (h i) UBC also recognises that new buildings can be designed with light wells and atriums to facilitate natural ventilation, day-lighting and passive cooling. UBC Design Guidelines 2.3.10 (c ii) UBC Technical Guidelines Division 15 governs the design and construction of building mechanical systems, including ventilated air. It is specified that no less than 50% of maximum air flow be available for variable volume terminals. If compliance is not met it must be demonstrated that appropriate ventilation rates are provided at lower air flow settings. UBC Technical Guidelines, 2010 Edition, Division 15 Division 8 considers the general requirements for windows and links to ventilation considerations. It states that operable windows should be included for ventilation and occupant comfort where noise and mechanical ventilation concerns do not preclude this. UBC Technical Guidelines, 2010 Edition, Division 18 4
17.4 Goals and Targets Table 16.1 lists the project goals and targets specifically related to the lighting strategies. For a complete list of all the goals and targets for CIRS, refer to Section 4.0 Goals & Targets. Category Goals Targets 6 REDUCTION(HVAC) Design CIRS to be as simple and passive as possible. 15 - AIR QUALITY The building will provide the purest possible indoor air quality. 16 - OXYGENATION The building will oxygenate indoor and exterior environments on an annual basis. 17 - COMFORT & CONTROL Provide local control over comfort conditions to adapt to individual differences and differing inhabitations. Table 17.1 Goals and Targets for the CIRS Ventilation System. Air that meets or exceeds outdoor air quality Preclude the use of materials on the Living Building Challenge Red List RATING SYSTEMS The ventilation strategies used in CIRS contributed to the achievement of LEED credits and Living Building Challenge petals, as listed below. For more information on the ratings systems and CIRS refer to Section 19.0 Rating Systems. LEED Energy & Atmosphere credits: Prerequisite 2 - Minimum Energy Performance Prerequisite 3 CFC Reduction in HVACR equipment 1.1 1.5 - Optimize Energy Performance Indoor Environmental Quality Credits: Prerequisites 1- Minimum IAQ Performance 2 Increase Ventilation Effectiveness 6.1 & 6.2 Controllability of Systems 7.1 & 7.2 Thermal Comfort Living Building Challenge 7 Net Zero Energy 8 Civilized Environment 9 Healthy Air 16 - Human Scale & Humane Places 5
CIRS TECHNICAL MANUAL RELATED SECTIONS: 3.0 Vision& Leadership 4.0 Goals & Targets 7.0 Building Design 8.0 Design Process 9.0 Structural System & Wood 11.0 Energy Systems 16.0 Lighting 18.0 Building Rating Systems 19.0 Monitoring & Measurement 20.0 Construction 22.0 Inhabitants vs. Occupants 17.5 Benefits The ventilation strategy at CIRS benefits the project in the following ways: Allows Control of Comfort Manual operable windows at both desk height and near the underside of the floor slab, allow inhabitants to control the airflow and temperature of both their office and personal space and adjust for their individual comfort. Changes in the temperature of mechanically supplied air can be requested through interface with the Building Management System. Improves Inhabitant Health Access to fresh air provides health benefits and improves the mood of inhabitants. Adequate supplies of fresh air are directly related to improved concentration and working productivity. Connects Inhabitants to Nature Operable windows connect inhabitants to the natural world by allowing them to feel the temperature and moisture of the air and giving them access to fresh air. Reduces Energy Consumption Using a mix of natural and displacement ventilation minimises the amount of energy required to ventilate the building. 17.6 Challenges The ventilation strategy at CIRS was challenging for the project in the following ways: Configuring Flexible Floor Space The cross ventilation strategy relies on the movement of air through open spaces across narrow floor plates between operable facades. The office wings were originally designed as a mix of closed offices and open office spaces that allowed for natural cross-ventilation and air movement. During tenant fit-out, a more significant amount of the space was converted to closed offices with high partitions. This change may reduce the effectiveness of the cross-ventilation strategy. Coordinating Services in the Raised Space The ducting for the mechanical ventilation is one of many services that are run in the space under the raised floor. Adequate space and access must be provided for mechanical systems in coordination with the needs of the other systems. 6
Coordinating Tenant Spaces Partition walls on a floor divided into separate suites must be properly coordinated with the displacement ventilation openings in the raised access floor. To ensure acoustic privacy between offices or suites, under floor partitions should be considered. Operating the Clerestory Windows The clerestory windows are a key element in the natural ventilation strategy in the office block and were originally operated by an automated system. The automated system was removed from the project due to concerns about cost, long-term maintenance and operations. They were replaced by a manual system that individually operates the windows using pole cranks. The reduced convenience of the manual system compared to an automated system may lead to the inhabitants underutilizing the natural ventilation system. RESOURCES: Diagrams links Drawings links Perkins + Will: www. perkinswill.ca Stantec: www.stantec.com UBC Campus Plan UBC Climate Action Plan: www.sustain.ubc.ca/climateaction 17.7 Lessons Learned The experience gained through the ventilation strategy for CIRS provided valuable lessons to apply to future project. Some of the key lessons are: Resolve Interior Layouts with Ventilation Strategy Understanding how tenants will actually use the space, especially the way in which the space will be subdivided, is critical to ensure that natural ventilation will be effective. Coordinate Services in the Raised Access Floor Spaces Coordinate the order of installation along with the layout of all the systems in a raised floor. Ensure sufficient lengths of communication cables are allowed in case changes in space configuration are needed. Facilitate Inhabitant Interaction with the Building Systems If inhabitants are meant to engage with the building to effectively mediate their environment in a sustainable manner while building functions must be easily accessible to them. Automated systems for difficult to access building components assist inhabitants in adapting the building to their needs; if replaced by manual systems adequate tools must be provided to inhabitants to make operations easy. Balance Acoustic Privacy and Ventilation It is challenging to balance the inhabitants needs for acoustic privacy with ventilation requirements in a naturally ventilated space. Work with project stakeholders during the design phases to determine the acoustic privacy requirements while developing the ventilation strategy. 17.8 Future Learning Additional lessons learned over the operational life of the building will be added at periodic intervals 7