Peteris Lazovskis, Harvard Graduate School of Design (GSD), Cambridge, MA, USA

Tectonic Ventilation: Establishing Design Parameters to Harness Buoyant Air Through Mass, Distribution and Recovery

The simultaneous challenges of energy efficiency and interior climate regulation have led to the increased sophistication of temperature and air delivery systems. While generally effective at responding to such challenges, mechanical systems are often formally autonomous entities that, at best, are complementary, and at worst, disruptive, to spatial and structural intent.

In the drive towards holistic sustainable design, where mechanical functions are intrinsic to the shapes and masses of architecture, numerous projects completed in the last fifty years have adapted natural heating, cooling and ventilation methods, reinforced by technologically advanced systems. In many cases, computational fluid dynamics (CFD) has aided designs approach desired interior airflows through digital simulation, with some projects using water bath modeling (WBM) as an analogue alternative.

For the “Airflow Carving” project, I used thermally driven WBM to simulate the way natural convection can be harnessed by a radiant mass feeding it into a distribution labyrinth, thereby ventilating interior space during a warming cycle. My subsequent research suggested that the addition of an energy recovery loop could help maintain a constant interior temperature differential irrespective of season, thus driving ventilation in a cooling cycle as well.

Sustainability has become a core principle of architecture and construction in North America. Winners of the Holcim Awards for Sustainable Construction presented in Chicago show how the leading edge of sustainable design means reaching far beyond “common sense”. Their approaches use proven instruments that are cleverly applied to improve the quality of life. So the world builds better.

The design exploration begins with a set of provocative questions pertaining to the climate control of buildings and the design implications of alternative approaches to cooling, ventilation, and lighting in construction. Can a building’s thermal mass be great enough to maintain a stable ambient temperature, while providing adequate ventilation, in a temperate northern climate? Can the flow of air be guided through a building with only architectural elements, and without ducts? Which materials can be used to improve a building’s comfort level? In order to answer the questions, a series of experiments were undertaken in a laboratory setting. Using airflow as a carving agent through the building’s mass, architectural propositions were tested, while avoiding ventilation ducts. A combination of concrete and rammed earth is furthermore used as a construction material to maintain constant ambient temperature levels and thus enhance the structure’s comfort provision for users. 

Planet - thermal battery as simple energy saver

Can a thermal mass be big enough to maintain a stable ambient temperature, and provide adequate ventilation, in a northern climate? Moreover, can it do so for an entire institutional building? Buoyancy driven ventilation systems - and their consequential temperature-maintenance systems, can save energy, and work well in seasonally similar climates, as these can predictably provide livable interior conditions year-round. Places that use a disproportionately large amount of the earth’s available energy, however, are not in such climate zones, for example Boston. As such, a simple, monolithic “thermal battery” can be radiantly heated and cooled if water piped within it, and air channeled through its pores to deliver ventilation and temperature difference to desired spaces.