High Performing Buildings - Summer 2011 - (Page 57)

Above Variable speed pumps in the mechanical room move on average over 1,700 gallons per minute of heat transfer fluid (HTF) between the lake and the building. Heat is transferred to the lake in summer and from the lake in winter. The HTF is a 20% propylene glycol and water solution, which is nontoxic, biodegradable, and FDA approved. Right This stormwater infiltration pond serves the surrounding area. Great River Energy minimized paved areas and increased landscaped areas, helping to reduce stormwater runoff by more than 25%. Collected rainwater is filtered and used in toilets and urinals, helping to reduce potable water use by more than 85%. © lucie marusin ventilation system. This design created the need for extensive exceptional calculations, testing the boundaries of the energy model. The gap between proposed and actual heating energy was complicated further because plug load and lighting energy were less than anticipated, reducing internal heat loads and increasing heating demand. The actual energy used for heating exceeded the predictions by about 3 kBtu/ft2, or 30%. While this may seem like a significant difference, L a k e c o o L i n g s c h e m at i c A lake geothermal heat pump system is coupled with underfloor displacement ventilation to provide an efficient, all electric heating and cooling system for the building. Thermal modeling of lake indicated minimal impact on water temperature. Degrees F 86.0 82.7 79.5 76.2 72.9 69.6 66.4 63.1 59.8 56.5 50.0 Building Makeup Air Unit Exhaust Outside Air Water to Water Heat Pump “Free Cooling” Heat Pump In Floor Diffuser Fan Coil 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 57 © dunham Associates Plenum Space © lucie marusin

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