Recent research conducted by three Minnesota State University, Mankato professors suggest solar thermal walls can cut heating ventilation costs by 20 percent. Researchers Patrick Tebbe, Louis Schwartzkopf and Saeed Moaveni devoted three years of time and effort to the project with help from students in the MSU engineering and physics departments.
The solar walls are made of dark aluminum or steel collector plates with tiny holes covering the surface attached to walls facing the south. The sun is supposed to heat the metal surface, transferring that heat energy into thin layers of air on either side of the panel. The air is then circulated by a fan and pulled through the perforated holes and eventually the heated air is cycled and moved into the building.
The solar thermal wall was originally developed in the ’90s by Conserval Engineering Incorporated. Before Conserval introduced the product, the company spent several years on research and development.
The research project, which took nearly three years, was conducted in three large buildings in the Twin Cities: a school, a police station and a manufacturing facility. The study was expected to estimate the total savings in cost, effectiveness and longevity of the product in Minnesota climates.
Test buildings resulted by a nine percent to 20 percent a year savings. In its first year of use, one building saved $2,400. Researchers concluded larger facilities could save even more. “Using solar energy to heat ventilation air means that managers of large buildings can use less fossil fuel and reduce greenhouse gas emissions,” said Schwartzkopf. “And the savings can be substantial. Payback times can be from one to eight years.”
A solar thermal wall is installed in addition to a regular building wall, so it is easy to apply the mountings to large buildings. Solar walls are also virtually maintenance free. “Solar thermal walls can operate for a decade or longer with little degradation in performance,” Schwartzkopf said.
Solar thermal walls can be cost effective towards natural gas and electric heating for large buildings such as commercial businesses, manufacturers, nonprofit headquarters and government agencies.
Not only do solar thermal walls save money, the walls generally produce fewer greenhouse gases, helping the environment. The emissions measured by the three researchers showed up to 20 percent in a year for the installations studied. This is just one step toward creating a clean and efficient future with a little extra money put back into pockets.