Rio Tinto Alcan Planetarium

Montreal’s Rio Tinto Alcan Planetarium has received an overwhelming amount of attention since it opened on April 6 last year. Visitors were amazed by the design, beauty and comfort of the facilities.

The new building is part of the Montreal Espace pour la vie (Space for Life) group of museums in the Olympic Park district and was constructed next to the Biodôme. The Planetarium is an educational, cultural and scientific museum that aims to direct the population’s interest towards the natural sciences, specifically astronomy. It is the largest planetarium in Canada, with a capacity to host 375 people.

The 86,080 sq.ft. building has two theatres beneath two distinctive, enormous tilted pillars. It also includes exhibition halls, laboratories, meeting rooms, shops, restaurants and offices.

The Milky Way Theatre, which seats approximately 200, is the traditional astronomical facility where visitors study and learn about the stars in the sky. In the second hall, dubbed the Chaos Theatre, visitors sit back and relax on bean bags and are taken for a 20-minute multimedia odyssey through the universe. There is also a permanent interactive exhibition with projections and multimedia games that ponder the question of whether life exists beyond Earth, and an area displaying the largest public collection of meteorites in Quebec.

The building was designed by a joint venture of Cardin Ramirez Julien and AEdifica Architecture + Design. The structural and civil design was by SNC-Lavalin, and the mechanical and electrical design, which included the design of the interior and exterior lighting concepts, was by our firm, Dupras Ledoux.

In regard to the unique construction of this building, the project was greatly challenging. The City of Montreal requested that the building achieve Platinum level LEED Canada NC 1.0 certification. The objective was to accumulate 54-57 out of a possible total 70 LEED points.

Most of the project team members are certified LEED specialists in Quebec, which contributed to their keen interest in working with this type of sustainable development and renewable energy construction.

Exchanges energy with the adjacent Biodôme

The neighbouring Biodôme uses an open geothermic loop, together with high-efficiency equipment. [See Canadian Consulting Engineer, August-September 2010.] This building consumes a lot of heat and air conditioning simultaneously in order to maintain the ideal climate conditions in its different exhibition zones: arctic, tropical, marine, and dry desert.

The objective for the Planetarium was to recycle excessive heat or cooling from the Biodôme to maintain certain of the Planetarium’s energy needs. Thus the largest portion of the Planetarium’s energy requirements are generated by the Biodôme. The complementary effects between the two buildings permit diversity between the thermal capacities of each facility and optimize the use of the geothermal open well.

In order to achieve an efficient energy exchange between the two buildings, the Planetarium equipment and systems were conceived with similar operating temperatures to the Biodôme. Specification adjustments such as an oversized heating coil were made to the initial design to accommodate a very low temperature heating supply at around 85°F.

Early in the design process, it was determined that the building automated controls should also be centralized into the Biodôme mainframe system. It is essential to have a good amount of dynamic data in order to produce heating and cooling simultaneously at an optimal cost. The heat pumps are screw type equipment and allow a coefficient of performance (COP) of 7 in certain conditions (7 kW of energy generated with 1kW of electricity). The actual challenge is to keep the efficiency at a maximum point in all sorts of conditions and operating schedules based on trends and historical data.

The Planetarium has a heat pump that generates heat or cooler temperatures based on the results of the neighbouring building’s capacities to produce these requirements. This heat pump can ensure 100% of the heating and a portion of the cooling needs. Thus, the air-conditioning of the Planetarium is provided by the Biodome, but with a portion provided by the Planetarium when needed.

The heat pump system is installed throughout a primary distribution network at a constant speed and a secondary variable speed. The heating temperature is adjustable based on the demand of the critical zone. An electric boiler is installed in case of failure from the heat pump. The cooling temperature is constant and the flow is modulated to maintain a return temperature of 55°F. A feed temperature between 95°F and 100°F is sufficient to heat the building in the winter.

A BTU meter is installed on each of the networks between the Biodôme and the Planetarium to measure the energy of cooling and heating exchanged each way. The value of energy is modulating depending on the season and time of day.

Heat rejected from the equipment, lighting and visitors in the Planetarium is entirely recuperated by the cooled water circulation system and transferred to the heated water circulation in the winter. In the summer, heat used to dehumidify the air is 100% recuperated from the cooling condensers.

According to the energy simulation model, the Planetarium surpasses the performance of a building referenced by ASHRAE 90.1-1999 by 50.6% for the regulated energy and achieves 8 points out of 10 on the LEED Canada scale.

Hybrid ventilation and massive heat recovery

The office space, halls, training rooms and exposition rooms are ventilated through the floor, while the theatre areas are ventilated from the walls with the help of a combination of displacement diffusers and adjustable nozzles, all while respecting NC20 acoustic requirements.

The air treatment systems are subdivided by thermal and occupant zones, using a fan-coil variable heating-coil and cooling-coil unit. All these units are connected to a high performance centralized fresh-air system.

In order to limit the amount of fresh-air injected into each of these zones, when the exterior conditions are extreme, CO2 sensors are used to control the quantity of fresh air used.

The heat from the evacuated air of all systems is recuperated by a massive, high efficiency (80-95%) system. The system recuperates latent and sensible energy in winter and summer. The fresh-air central system has a water atomization humidification system which is adiabatic and allows low temperature energy usage as a source of heat.

Windows and dampers are installed on the outer walls of the halls and in the cone-shaped roofs to allow natural hybrid ventilation when the conditions permit. The shapes of the building as well as the large open areas were key elements when creating effective air sweeping of the entire space. This ventilation system does not replace the mechanical system, but is a hybrid that reduces the air-conditioning charge, while increasing the quality of indoor air. The system is also used to produce nocturnal purging.

Two large reservoirs

The building contains two large water reservoirs, which each accumulate 40,000 litres of rain water from the roofs and terraces. A filtration system and chemical treatment ensure the quality of this grey water, which is used in the toilets and urinals.

Thanks to the use of rainwater, the decrease in drinking water consumption for the building is 59% below the LEED Canada building requirements.

All the plumbing equipment was selected with care. Low flow sinks, low consumption toilets and urinals all have movement sensors, while thermostatic mixing valves were installed to control the water temperatures for showers and sinks. The domestic hot water is produced locally in small tanks.

Lighting objectives

Platinum LEED certification:

• Reduce the maximum amount of energy consumption, while using natural light
ing;

• Avoid light pollution projected on site towards the sky in support of observing the stars;

• Reduce the maximum quantity of mercury content

in the lamps used.

Lighting quality:

• Provide a very high quality of lighting by creating

appropriate levels of lighting for the visibility and

comfort requirements;

• Create flexibility in the lighting to adapt to the various activities;

• Accentuate the architectural concepts;

• Create inviting, mysterious and futuristic ambient

lighting to engage the visitors;

• Create a strong and unique identity for the

new planetarium.

Respect the budget.

Avoiding light pollution and mercury

High performance lighting, dimmable ballasts, and high efficiency lamps with low energy consumption (LED, fluorescent T5 or T8) are used with a high-tech centralized control system that works with motion detectors. The system controls “on-off” functions in the entire building, based on programmable lighting control schedules.

Design calculations showed an energy consumption approximately 45% less than the referenced building ASHRAE 90.1 (0.9W/pc versus 1.6W/pc), which is an exceptional result.

Almost all of the light fixtures in the building and the exterior surroundings use LED lamps. These light fixtures are a “full cutoff” type (i.e. the light stream is oriented downwards) or they are directed towards the ground. The strategy helps limit the amount of light pollution and improves the observation of stars.

Only lights that have a low or non-existent mercury content have been used. The LED lamps, of which a large number were used, do not contain mercury. For fluorescent or metal halogen bulbs, only those with the lowest levels containing mercury were selected. Based on calculations, the level of mercury detected is well below the level permitted by LEED.

Creating a mysterious and futuristic ambiance

A variety of lighting levels creates a subtle difference from one area to the next while the control system and the choice of gradual lighting allows specific activities and ambiances. For example in the activity room the lighting scenarios can adapt to various activities such as training, projection and conferences. In the halls the low level of lighting creates a calm and mysterious environment that stimulates the curiosity of guests prior to their experience in the theatres where they enjoy the lighting effects and artificial projections.

The lighting concept also provides a distinctive character to the building. In the main hall, for example, simple tube lighting is suspended in a creation inspired by the movement of planets and stars. This thematic idea, which visitors, particularly children, can relate to, is also seen in the group eating areas where the lighting portrays flying saucers. In addition, the DEL RGB lighting in the hallways is programmed to illuminate naturally in the following order: sunrise, sunset, and night.

To emphasize the exterior landscape design, lighting has been incorporated into many of the elements, such as railings and canopies. On one side of the curved benches, for example, the lights create an illusion of planets coming out of the ground, and on the other side blue lights project in streams to the ground, creating a futuristic and mysterious effect.

The inner courtyard hidden at the main entrance requires special lighting to accentuate the concept of fallen meteorites and the illusion of them marking the earth. The rocks placed randomly in this area are lit by accent lighting, while beams of coloured light project onto a perforated wall background to create different lighting effects (aurora borealis, midnight blue, etc.).

Having a limited budget was a difficult challenge for a building with such a large area and several particular spaces. By careful planning, the team created an exceptional design and quality in the most important areas of the building, and provided economical solutions to the secondary areas such as the warehouse, service areas etc.

Regardless of budget constraints, site constraints and the complexity of the project, the lighting concept not only has exceeded the set criteria, but also has given a unique identity to the new Planetarium.cce

Laurent Laframboise, ing. is a mechanical engineer and Hieu Trong Nguyen, B.Arch. is a lighting specialist with Dupras Ledoux in Montreal.

Project: Rio Tinto Alcan

Planetarium

Owner-client: Ville de Montreal, Espace pour la vie

Mechanical, electrical & lighting engineers: Dupras Ledoux

(André Dupras ing.

Laurent Laframboise ing.,

Khalid Saadaoui ing.)

Architect: Cardin Ramirez Julien and Aedifica Architecture + Design

Structural: SNC-Lavalin

Landscape architecture:

Fauteux and associés