City of North Vancouver Public Library

Sustainability - LEED

As part of its ongoing sustainability program The City of North Vancouver has adopted the LEED Green Building Rating System. They have made a commitment to reduce environmental impact, save energy and reduce operational costs as well as provide long term benefits for the community. The minimum acceptable building standard for new civic buildings is LEED silver certification. The preferred standard is LEED Gold and the City of North Vancouver Public Library is attempting to achieve LEED Gold certification.

Solar Strategies

To prevent excess solar heat gain, sunshades span the south facade of the building at each level. The exterior sunshades and fritted glass eliminate over 75% of the solar heat gain through the windows substantially reducing the cooling load inside the building and keeping the comfort conditions a lot more stable along the exterior zones.The glass windows have been selected for a higher than normal thermal resistance (Low-e Coating and Argon filled) to reduce the heat loss from the building in winter, as well as to keep the inside surface temperature of the glass from getting too cold and creating a radiant cooling panel in the wintertime. The fritted glass at high level above the sunshade allows daylight penetration further into the interior of the building without additional solar heat gains

A prominent feature of the south elevation is the 3 sets of solar hot water panels installed on the roof of the monitor and on two wings beside it. The solar array, consisting of 120 panels, provides nearly 20% of the total heating requirements to the building and will provide supplemental heat to the LEC District energy system during the summer and during sunny conditions throughout the year.

A geo-exchange ground loop system provides cooling for the library. Flexible pipes are installed horizontally and vertically underneath the structure. Cool water is delivered by the pipes to a radiant system within the building. The combination, geo-exchange heating and cooling as well as solar energy, will meet the energy needs of the new library and service the Central Lonsdale Power Plant.

Energy

The building incorporates many energy saving measures, including environmentally friendly energy sources, reduced demand through good design and construction, efficient mechanical systems and efficient lighting. Altogether, the strategies employed will save over 60% of energy cost compared to a typical new building.

Heating energy for the Library will come from three sources: - a district heating system - solar hot water panels - a geoexchange ground loop system

The building is be tied into Lonsdale Energy Commission’s (LEC) District Heating System, which is being set up to provide central plant heating to several buildings being built in the area. The Lonsdale Energy Plant consists of high efficiency condensing boilers, with a supplemental solar water heating array located on the roof of the Library itself.

Mechanical Systems

The HVAC system has been designed for low energy consumption, low noise inside the Library space, low maintenance, simple operation, and long system operating life for a low life cycle cost.

The building's concrete structure is one of the primary “air conditioning systems.” It uses a series of over 6,000 meters of tubes cast right into the concrete slabs to deliver heating and cooling. The radiant slabs act as a large thermal storage device. This design will provide comfortable, “steady state” room temperature all year.

Ventilation will be provided by a combination of both natural and mechanical systems. The passive, natural ventilation component uses openable windows at occupant level with a motorized clerestory window above to promote air flow.

The active, mechanical ventilation uses a heat recovery system. Heat is drawn from the exhaust air being vented from the building and used to heat up the fresh air entering the building. This saves energy and provides a more comfortable environment for building occupants.

Envelope

The exterior walls of the building (the envelope) are designed to minimize heat transfer. The is achieved through the use of highly efficient windows, a good window to wall ratio, and construction detailing to reduce thermal bridging at the envelope. On the south façade, windows allow for extensive daylight penetration while exterior shading devices reduce solar heat gains and glare.

Lighting

All lights are controlled from dimming controllers and occupancy sensors to reduce electric lighting use to the as-required operation. Extensive day lighting is obtained from a large north facing clerestory roof monitor and open atria down through the central area of the building. The lighting systems are designed to use less than 1 watt per square foot. All light bulbs and fixtures are selected to use low wattage compact fluorescent and other high efficiency lamps.

Water Consumption

The plumbing systems include low-flow fixtures which will help reduce water use by over a third. Localized small electric hot water tanks are used at remote washroom groups. These localized hot water tank systems minimize the amount of hot water piping lengths and therefore reduce standby energy losses.

Stormwater Management

Outside the building, environmental impacts are mitigated through landscaping and stormwater management. The top floor features a vegetated green roof.

All roof drains are designed to control water flow, using the library roof as a retention pond, reducing the roof surface stormwater flow rate to 25% below standard roof drain flow rates.

The Parking area drains are routed through an oil and sediment interceptor resulting in the removal of more than 80% of suspended solids and hydrocarbon contaminants. Phosphorus and plant fertilizers are not used on this site saving the need for treatment.

All of the site stormwater is directed to two bio-swales specifically constructed as part of the project’s development and overall site development. Stormwater falling on the impervious plaza surface is routed through sediment bucket type drains and a main storm drain sediment interceptor at the connection to the municipal storm sewer.

These measures reduce the strain on municipal systems and natural waterways.

Indoor Environmental Quality

In order to promote a healthy, comfortable indoor environment, the library will make use of Carbon dioxide monitoring and effective ventilation. The ventilation system was flushed out after construction and effectiveness will be measured to ensure high quality air within the building. Causes of pollution will be controlled at their source. Library staff and patrons will have a high level of control of temperature, lighting and ventilation systems, ensuring a comfortable and productive environment.

Green Housekeeping

Products used to clean library facility will be environmentally friendly.