High Performing Buildings - Summer 2011 - (Page 35)

Water Conservation native landscaping eliminates irrigation, underground storage system for collecting storm water to eliminate runoff, underground storage system for fire suppression system, low-flow toilets and sinks Recycled Materials exterior wood timbers harvested from a local barn built more than 100 years ago; landfill impact reduced 75% by diverting metal, cardboard, and wood construction waste to a recycling center Photo by Tim Schoon Photography, courtesy of lSC design, inc. K e y S u Stain aB Le F e at uR e S BuiLding enveLope Roof Type Preweathered standing seam metal roof panels with structural insulated panel system overall r-value r-31.12 reflectivity 25.37 Walls Type more than 30 wall types are used on this facility, including insulated metal panels, textured masonry, and stone veneer overall r-value r-31.1 (average of all wall types) glazing percentage 10% Basement/Foundation Basement wall insulation r-value r-3.39 Basement floor r-value r-0.38 (4 in. concrete slab Windows u-value 0.5 Solar Heat gain Coefficient (SHgC) 0.4785 or 0.55 shading coefficient Location latitude 39.81 the geothermal water, and between the return chilled water loop and the geothermal water. During summer operation, if the hot water return temperature exceeds its setpoint, the twoway control valve at the condenser heat exchanger modulates open, allowing excessive heat to be rejected into the geothermal water. During winter operation, the cooling loads are not sufficient to provide adequate hot water temperature. The two-way control valve at the evaporator heat exchanger modulates open, allowing heat from the geothermal water into the return chilled water flow and then into the condenser hot water loop. The chillers’ energy efficiency ratio (EER) is 30 and the heating coefficient of performance (COP) is 5.5. These are the nominal cooling and heating efficiencies, which vary with the building loads and the geothermal water temperatures. Designing the system with 10 heat recovery chiller modules makes it possible to run partial loads by only using the number of chillers necessary to maintain the temperature and humidity setpoints. This setup is more cost effective than running partial loads on a system designed with one 500 ton chiller that consumes more kW/ton. The multiple module system also serves as a backup so that if one chiller goes down, nine more can pick up the slack. The plant also contains the geothermal heat exchanger, which provides the condenser with geothermal water for the heat recovery chillers, energy recovery units with built-in heat pumps, and multiple water-to-air heat pump units. No water-to-water heat The porch of the bookstore and gift store and Ford Education Center features timbers harvested from a local barn that was more than 100 years old. pumps were used in this system. The condensing gas-fired boilers, working on 98% efficiency, were installed as a backup system in case of emergency. Twelve air-handling units (AHUs) supply hot or cooled and dehumidified air into 12 zones throughout the facility. Each zone is controlled by its own AHU to maintain the required thermal properties. Since each zone requires humidification during winter operation, a VAV type system was not recommended. Each AHU is equipped with hot water preheat coils, chilled water coils, and reheat coils. Two of the AHUs supply approximately 50% outside air and are equipped with enthalpy wheels. The AHUs in the museum’s critical zones such as the Cyclorama, collection storage, gallery, and photo storage are equipped with five air filter modules, including carbon filters. The five energy recovery units (ERUs) with built-in heat pumps supply outside air into the food service areas, offices, and theaters. The ERUs for the food service and 35 Summer 2011 H i g H P e r f o r m i n g B u i l d i n g S

Table of Contents for the Digital Edition of High Performing Buildings - Summer 2011

Commentary
Contents
Stanford University's Y2E2
The Christman Building
The Gettysburg National Military Park Museum and Visitor Center
Cannon Design Regional Offices, Power House
Great River Energy Headquarters
Letters
Products
Advertisers Index

High Performing Buildings - Summer 2011