For a nonprofit located on the shores of Lake Michigan and an adolescent treatment center in Minnesota, geothermal heat pump systems have been an upfront investment that pays off in terms of maintenance, ROI, and effectiveness within an integrated sustainable design.
Chicago’s Michael A. Bilandic Building has 21 stories, one for each year since the previous retrofit. Recently, an open-minded project team paired modular chillers and hydronic gas boilers with pumps and VFDs to conquer some upgrade challenges, bring the mechanical system into the 21st century, and knock 15% off the tower’s measured energy use.
From sidewalks to hospital entrances and helipads, these systems are becoming a more common part of a project’s mechanical infrastructure. Examine differences between ASHRAE’s old and updated classifications, then review design considerations such as heat of evaporation, heat loss to the atmosphere, and back and edge losses. Tubing, spacing strategies, and controls round out the primer.
Leaning on experience and data from various K-12 cities and projects, the author pursues some less conventional design approaches. They may revolve around radiant heating and/or cooling, but depending on school size and other factors, the smart use of heat recovery, DOAS, and improved central plants could also put a project on the HVAC honor roll.