Eielson installs new SolarWall Published Oct. 20, 2011 By Robin Liggett 354th Civil Engineer Squadron EIELSON AIR FORCE BASE, Alaska -- Anyone that has driven on Industrial Drive may have noticed the south wall on the vehicle operations building seems a lot browner. The new wall is part of the first SolarWall passive heating system installed on Eielson Air Force Base. The brown metal siding is perforated so fresh outside air can enter the space between the brown siding and the actual building's wall. The dark brown color of the metal siding is good at absorbing heat from the sun which in turn heats the air in the space between the two walls. The heated air rises in the wall space until it is pulled into the facility through a damper that opens and closes based on the temperature in the SolarWall, providing the facility with free hot air which reduces the load on the facility's existing heating system. It would seem that there's no way this system could actually work because there's no sun at Eielson in the winter, however, that is a common misconception. We're not expecting to see much freely heated air coming into the facility during December and January, but the heating season at Eielson lasts considerably longer than those two dark months. By using the solar radiation data for the exact longitude and latitude of the wall, the system is estimated to save over 1,100 million British Thermal Units of heat each year, which equates to over $15,000 a year in avoided steam production costs. And don't worry, in the summer when the nice warm days and midnight sun is back, the SolarWall system won't be creating a sauna in the Vehicle Ops bay. The damper will be closed and the hot air will be naturally vented through the perforations in the upper portion of the brown exterior wall. Because the SolarWall is absorbing all of the solar radiation, the inside wall is in effect in the shade, so the building will actually stay cooler in the heat of the summer. A detailed monitoring system is being installed on the SolarWall so that real-time temperatures and system performance can be logged and tracked. Keep your eyes peeled next summer for an update when we find out how much hot air we actually got the system to make for us.