Observatory Roof Deicing
The Smithsonian Institution’s Fred Lawrence Whipple Observatory is located southeast of Tucson, Arizona. While Arizona doesn’t exactly conjure up images of snow and ice, the observatory is located in the mountains at 8,585 feet and regularly deals with winter weather.
One of the best times for using the observatory’s telescope is immediately following a storm when the skies are clear. Snow presents a problem as it can fall inside the structure and damage equipment when the roof is opened for the telescope.
To allow the telescope to function year round without worrying about snow and ice on the roof, Warmquest provided an Invizimelt deicing system to be installed beneath the metal roof covering. 2700 feet of low voltage Tuff Cable was installed in aluminum Invizimelt panels and fastened to the sub roof. The Tuff Cable is installed and spaced so that it produces 21 watts per square foot. The metal roofing panels were then installed over the Invizimelt.
The facility also requested that the safety tie off points on the roof be kept ice free. This provides year round access for any maintenance or other work on the roof. This was accomplished with 100 feet of our self regulating GutterMelt which was installed around the safety tie off points.
The entire system is operated off of an automated temperature and moisture sensor. This activates the system when the ambient air temperature drops below 38°F and the sensor detects moisture. This ensures the roof stays clear at all times. A manual timer was provided as an alternative if the system ever needed to be run without a storm.
Among the unique challenges for this project, was working around the moving structure. Not only does the roof open up for the telescope, but this observatory was the first telescope housed in a rotating building. As the system was designed and installed, planning was required to allow for the opening of the roof and the rotation of the entire building.