Radiant Floor Heating with Solar Thermal
Project (Summer 2012): Solar Thermal Energy for Winter Radiant Heating
Place: Custer, Wisconsin
Purchaser: Midwest Renewable Energy Association
The Midwest Renewable Energy Association (MREA) is a non-profit based in Custer, Wis. For the past 25 years, the MREA has been committed to educating homeowners, businesses and local governments concerning renewable energy and sustainable living solutions. In 2012, the organization was investigating deploying an energy efficient solution to heat their training building during the winter months. Because the building is used most often during the milder spring and summer months, the building can be kept at a much lower ambient temperature during the winter. Combining an advantageous roof pitch (60° angle) and radiant tubing built into the existing floor, solar thermal was an obvious radiant heat solution.
MREA decided to flush roof mount the system using Caleffi solar racking. Ten StarMax V™ panels would provide the necessary heating capacity. Because the fifth port on the bottom of the StarMax V accommodates the slope to ensure proper drainage, an aesthetically pleasing drainback design was utilized so that typical panel tilting could be avoided. The patented internal design of the StarMax V features two internal headers that are sloped to the center and a bottom outlet on each collector allowing all collectors to be mounted at an even height in a drainback system.
During design and installation project stages, the MREA hosted training sessions for solar thermal installers including MREA instructors and students. The students designed and installed the resulting drainback system, reinforcing MREA's educational vision. With the Caleffi drainback system deployed, the building is kept at 40°F from November to February. The system not only provides enough Btu’s for heating, but also fulfills any domestic hot water needs. On a recent cold winter day at the training facility in January of 2013, a daunting -10°F outdoor air temperature was no match for the 150°F temperature generated from the StarMax V panels!
The Caleffi system is also used for hands-on training during the summer, assisting students in learning about solar thermal technologies and installation practices. The solar system is a valuable and visual demonstration that lends itself well to MREA's mission: educating members about practical, quality and cost-effective renewable and sustainable solutions as well as meeting the organization's need for a cost-effective method to heat the building during the cold winter months.
(photo's Courtesy of: Midwest Renewable Energy Association/ Amiee Wetmore)