4.421
Space-Conditioning Systems for Low-Carbon Buildings

Consensus understanding of climate change identifies a need to drastically reduce anthropogenic emissions of greenhouse gases in coming decades, including those associated with buildings. In this course, we seek a thermofluids understanding of the basics of natural and mechanical systems for conditioning high-performance buildings and will develop and assess systems based on this understanding. We will focus on options for the Metropolitan Warehouse, future home of the School of Architecture and Planning. Can this and other buildings, large or small, be ventilated without use of ducts and fans? Can they be maintained at a comfortable temperature with little or no use of mechanical systems?

We will investigate natural ventilation in detail. Topics include the thermal and fluid dynamics of airflow in buildings, application to multi-zone wind- and buoyancy-driven airflows, and adjustments in urban areas to account for reduced wind speeds. Performance assessments will be based on first-principles analyses and simulations that couple airflow and energy analysis programs. Building cooling strategies will be motivated by mapping conventional and innovative cooling systems on the psychrometric chart. First-principles analysis and simulations with an equation-based language, Modelica, and with EnergyPlus will be used to quantify the performance of energy recovery systems, membrane- and desiccant-based dehumidification, evaporative cooling, thermal storage at diurnal (building materials) and annual (ground-coupled heat pumps) scales and radiant cooling and heat-rejection systems. System design in leading commercial practice will be presented and critiqued. Working in groups and making use of design workflows under development at MIT and Harvard, we will assess climate- and building-specific systems on the basis of thermal comfort, energy consumption, carbon emissions and resilience to climate change.