As sustainability continues to be a goal of the building industry, designers are constantly looking for new ways to add energy efficiency and environmental integrity to their projects, particularly when it comes to heating, ventilating, and air-conditioning. While these activities are key to maintaining comfortable, healthy, and productive spaces, collectively they account for approximately 40 percent of the electricity used in commercial buildings, according to statistics published by the U.S. Small Business Administration.

One key way to improve energy performance and boost energy savings is through radiant heating and cooling, a technology that has been used in commercial spaces in Europe for more than three decades. Radiant systems have also been used throughout the U.S. and Canada, but in a limited manner, primarily for perimeter heating. Radiant panels used for heating and cooling meet metrics of high-performance building operation from the standpoint of energy use and cost effectiveness, and they provide design flexibility, easily being incorporated into the architectural finish in a manner that provides both function and architectural appeal.

Of particular interest is the use of chilled ceilings and chilled sails due to the potential for efficient design and increased occupant thermal comfort. This article will explore the environmental and operational characteristics of both chilled ceilings and chilled sails, with special attention to architectural applications in a variety of commercial spaces, including large spaces and specialized boutique projects.

The Principles of Radiant Heating and Cooling

Radiant systems provide heating or cooling directly to occupants and the occupied space. The systems depend on the principle of radiant heat transfer—the delivery or removal of thermal energy directly from one surface to another including the people and objects in the room. Because thermal conditioning is delivered directly to occupants, rather than via forced air movement, radiant systems offer improved comfort and greater energy efficiency than forced air systems. This higher efficiency results in significant energy savings. When used as the primary means of cooling and heating, a chilled ceiling system occupies a significant percentage of the overall ceiling. Because of this, it is typical for the chilled ceiling system design to be informed as much by the architectural team as the MEP consultant, in some cases more. It it not unusual for a ceiling to be integrated with the lighting and other services to offer a tailored solution on a project-by-project basis.

Radiant technology is a sustainable, aesthetically pleasing method of heating and cooling a space. Gensler, one of the world’s leading architecture firms, utilizes chilled sails in the firm’s Los Angeles office. Photo © Ryan Gobuty / Gensler