The use of mechanical means of heating, ventilation, and air conditioning (HVAC) came
about because of the combined ability and desire to control the interior building
environment in extreme climates.  The price of this ability to control the indoor climate is
beginning to surface in the form of air and water pollution from energy use, sick building
syndrome (SBS) from factors such as build-up of molds in air conditioning fluids, and
loss of individual control of one’s thermal environment.  All of these factors provide
motivation to re-incorporate natural ventilation as a hybrid strategy, taking the lead from
history as well as from advanced design, construction, and analysis techniques, to take
advantage of natural winds to reduce energy consumption and provide greater human
health and comfort while maintaining the flexibilities offered with conventional HVAC

This case study assesses a hybrid natural ventilation strategy against a traditional
mechanical HVAC system.  Tables 1 and 2 above  provide a summary of the primary
environmental, health & safety (wellness), and cultural benefits of hybrid natural
ventilation systems over conventional mechanical HVAC systems for the East Campus
Project, per the methodology described earlier.  Each major benefit is then described
and discussed, including an estimate of potential energy and emissions reductions and
a life cycle analysis (LCA) of the emissions from the manufacture of air-conditioning
equipment.  Throughout this case study, the term “natural ventilation (NV)â€� will
refer to a hybrid ventilation strategy that also makes use of a mechanical HVAC system
when exterior climatic conditions are not suitable for natural ventilation, as it is unlikely
that a pure natural ventilation system could meet the needs of the Boston climate.  A
hybrid system thus includes the relative advantages of a mechanical system, such as
reliability of performance and ability to filter air when needed.
Naturally Ventilating the East Campus Project