Case Study #3
Stone Court Villa – Capillary Mat Radiant Cooling System
The architect's concept was to snake stone walls through the existing mesquite and washes of a 10-acre desert site, capturing tranquil courts that awaken all the senses from the sound of running water to the smell of jasmine. One often overlooked but palpable aspect of the sensory experience is temperature control, which in the Sonoran desert can range from scorching summers to freezing winter nights.
While Stone Court Villa presents a tough yet honeycombed 3-inch thick skin of white Mexican travertine on its surface, an invisible filigree of capillary mats embedded in the ceilings above and a radiant temperature control system in the floor below channel the sap of life through slabs of concrete and plaster to maintain a quiet, constant and comfortable ambient temperature throughout the home.
The client also wanted freedom from the conventional hum of forced air for climate control. This type of home had only been attempted in Arizona once before by Dave Scheatzle, an ASU professor, architect and environmental control specialist who pioneered methods to achieve radiant cooling in the 1980s. The architect called us in to help because he knew that we’re obsessed with pushing boundaries in technique and technology. As we revisited Professor Scheatzle’s research nearly 30 years later, we were thrilled to tie all the systems together with smart technology that wasn’t readily available in the 80s. Sometimes good ideas just take patience to come to fruition.
“We like clients who are attracted to innovation,” says 180 Degrees Design + Build’s Principal Architect James Trahan AIA, who was also the construction and BIM modeling lead on the project. “Anyone can put flex duct in a room, but we’re driven by the thrill of innovation.”
Research & Development Through Prototyping
The client allowed us to do a full scale mockup on one of the caretakers’ quarters which let us experiment before committing to a solution. We discovered that we needed access to the perimeter of one side of each room’s ceiling for supply line maintenance, so we included a 3-inch wide metal panel on a piano hinge that’s flush with the plaster. This operable panel played a critical role in allowing access to our dew point sensors that controlled the system should our humidity rise to an unacceptable level that could create condensation.
The full scale mockup provided an incredible testing ground for our team, allowing us to run significant real-time tests to uncover any flaws with this very complex system.
Upon completion of our full scale mock-up we realized that the mechanical team that we originally selected were not cable of executing such a complex mechanical system and two that we needed to take the lead on the fabrication and installation process.
After all components were digitally modeled, we set our task to model every pipe, fitting, sensor, and control devices. We instructed out new mechanical sub to build exactly from our digital model and to not deviate any dimension more than one quarter of an inch. This model allowed the subcontractor to pre-componentize all parts prior to visiting the jobsite. This mass customization process worked as planned and installation went smoothly.
Through the mock-up process we also determined that installation would be much quicker if we pre-fabricated each mat on a room per room bases. These drawings were extrapolated to excel spreadsheets that create order lists for all mats used on the project. The drawings and spreadsheets were sent to Germany for fabrication.
The client’s role as a patron of innovation was critical; they were willing to invest in the research and development for the concept to make it work. They view the process as their contribution to the advancement of technology.
Great care is taken to protect adjacent building components, as well as protect installed components as soon as they are completed. Our scheduling overlays always strive to stagger subcontractors so that each can focus on their task at hand without the aggravation of working around others in the same general area.
We solved the client’s request for noise-free climate control by embedding capillary mats directly in the plaster ceilings. By maintaining the ceiling plane at a constant 60 degrees, heat is then drawn away from the body. The capillaries are filled with water, which is more efficient than air for heat transfer.
"It feels like a cave,” James marvels. “It’s one of the most comfortable sensations of cooling that you’ll ever experience."