Mechanical System & Green Design Initiative Narrative

The MEP system strategy for the building consists of combined passive and mechanical systems. The integration of passive green initiatives will help reduce the size and reliance on mechanical systems, reduce energy consumption, and provide for a better living environment for the building occupants. The specified systems are high efficiency systems with the intent to further conserve energy and minimize the environmental impact on our ecology.

Thermally massive construction utilizing concrete flat plate floor construction and concrete walls will allow for radiant heat exchange between the occupants providing a dampening affect as temperatures fluctuate both in the summer cooling months and during the winter heating months. Natural ventilation utilizing cross ventilation via operable windows and nighttime ventilation using the thermal stack effect will provide for cooling of the thermal mass. Building orientation along an east-west axis will facilitate the use of the thermal mass. The location of the plaza and the saw-tooth façade will act as a “scoop” to capture the prevailing winds and aid in the natural ventilation strategies employed.

The thermal loads on the building will be kept to a minimum using rain screen technology that will allow for continuous and uninterrupted insulation. The use of low-e, double thermal window glazing and shading devices on the south facing windows will allow for shading of the unwanted summer sunlight while allowing the winter sunlight to radiate the thermally massive slabs. East and west facing glazing will be triple-glazed with ventilated cavities to redirect the solar gain to the exterior during summer months and will provide shading via perforated blinds. A green planted roof shall also contribute to reducing the heat loads on the building and will reduce the heat island affect.

The lighting strategy for the building will be a combination of daylighting and electrical lighting. Daylighting is achieved through the use of toplighting and sidelighting. Toplighting is provided through skylights with diffuse glazing and the use of shading louvers to prohibit direct solar radiation from increasing cooling loads and to control glare. Sidelighting will be achieved with a lower view-and-daylight window in combination with a light shelf and high daylight-window. High ceiling heights and lightly colored interiors will assist with reflectance and distribution of the daylight admitted into the building. Electric lighting shall be achieved with fixtures of higher luminaire efficiency such as compact fluorescent fixtures with high efficiency ballasts. These shall be zoned with multiple switches to allow for flexible area lighting as daylighting values vary throughout the day.

The HVAC system shall consist of valance convectors to provide radiant heating and cooling in order to supplement the passive systems when they are insufficient to accommodate the desired comfort zones. The system shall be a four pipe hydronic system with hot water piping provided by two heat pumps. Chilled water shall be provided by a vertical closed loop piping system placed in a deep well and connected to a heat pump. The hydronic system allows for the indoor air quality and moisture control to be provided by a much smaller fresh air unit. The outside air shall be provided by roof-top units equipped with heat wheels to provide pre-heat or cool-down depending on the season. The heating and cooling coils will utilize the same hydronic system employed by the valence convectors. The heat pumps will run on boidiesel fuel stored in below ground fuel tanks. The boidiesel fuel provides a renewable, biodegradable, and non-toxic fuel source which produces 60-75% less carbon dioxide than traditional fuel oil. Potable hot water will be acquired by a heat pump connected to the public water supply.

Roof storm water will be collected and stored in a storage tank located at the parking deck. It will be filtered and pumped for re-use in irrigating the rain garden planters located in the plaza and parking areas. Pervious pavement will be utilized for the access drive to allow for filtration of storm water back into the soil. Native landscaping will be provided to beautify the property, provide buffering to the street noises and help reduce the heat island affect. A gabion retaining system will be employed along the railway to assist with grading.