GeoMass combines two building energy-management concepts: the ground-source heat pump and thermal mass. Ground-source heat pumps (sometimes called geothermal systems) leverage the constant temperature of the earth (about 55 degrees year-round at roughly 10 feet below the surface, in most locations) to make the heat pump cycle more efficient in both winter and summer. Thermal mass recognizes that some of the physical mass of a building can serve as a thermal storage to moderate temperature swings. GeoMass integrates both concepts in order to maximize benefits and reduce costs. A ground-source heat...

Pursuing energy efficiency in old buildings with tiny budgets demands improvisation and creativity; that’s one reason why we think it’s an ideal environment for experimentation and discovery.  Below are some discoveries that we’ve made along the way, which might be useful in other projects: Working in large old buildings guarantees a certain number of surprises.  Often there have been many different generations of heating, cooling, and ventilation systems installed over the history of the building.  Renovations have changed the shape of the space; the whole facility may be used for a different...

The OvalAir concept can often produce a dramatic increase in comfort with very little investment.  In some cases, old equipment has failed but we’ve been able to make spaces comfortable without replacing the equipment.  In general the space becomes much more “livable” in feel, without a big investment in ducting, air handling units, expensive HVAC controls, etc. At the moment it’s more of an experimental concept, but we think OvalAir may have the potential to be a disruptive innovation in HVAC and new building design. Imagine a building with no long and complicated enclosed ductwork, no...

“OvalAir” is a concept that we’re testing in a variety of spaces and organizations.  It’s a simple principle, based on the observation that many large facilities have hot and cold spaces, a wide range of temperature gradients, and local peaks and valleys, simultaneously.  Sometimes natural air circulation exacerbates the problem, in particular when hot air rises between floors or within a tall space. The tendency is to try to heat the cold spaces and cool the hot spaces with additional HVAC equipment and more complicated ductwork, requiring more energy and excess capacity.  The goal...

Thermostats are usually set to trigger heating when the air temperature falls below a certain point; similarly, cooling is triggered when the air temperature gets above a pre-set point. The range between those two points is called the “dead band” … neither heating or cooling is activated. The term “dead band” is not widely known outside the HVAC industry, but it’s useful in understanding the challenges (and opportunities) involved in keeping a space comfortable. If the two points are too close together, the HVAC system may cycle often between heating and cooling, particularly on a day of...