B&D was honored to have been selected as a 2019 AGC Best Buildings winner. B&D will be recognized on May 3 for Best Building (under $2.5M) for the Sandia Swimming Pool Facility Solar Thermal Boiler, Roofing Project. Here is an inside look at this amazing project:
Sandia Swimming Pool Facility Solar Thermal Boiler, Roofing Project
B&D Industries, Inc. prides themselves in supporting New Mexico’s growing renewable energy industry. Our state’s high UV index and environment make us a hotbed for the development of future solar energy technology.
B&D partnered with the City of Albuquerque, Albuquerque Public Schools and the New Mexico Solar Energy Association (NMSEA) in constructing the city’s first Kingspan Solar Tube Arrays at the Sandia High School pool facility. This project entailed installing a Kingspan Solar system that is used to heat the pool water at Sandia High School pool. B&D installed 60 A-frames on the roof that hold 1,800 solar tubes. The tubes harvest the sun’s energy to heat the pool water, reducing their use of fossil fuels. The A-Frames sit on large aluminum support beams that were installed by Building Envelope Services (BES). The beams sit on metal stanchions that were installed by DKG Roofing. The solar array took up approximately 2,680 sqft on the roof of the facility. The water/glycol passes through the tubes on the roof and then pass through a heat exchanger. The tubes harvest the sun’s energy to heat the pool water reducing their use of fossil fuels. In the first two weeks of operation, the tubes have produced over 50 million BTUs of clean energy.
The Solar Tubes operate on a “closed glycol-water loop system”. The photovoltaic ribbon faces the sun. Ultraviolet rays activate the ribbon by exciting electrons and generating energy in the form of heat. The heat is then transported to a copper diode; which can reach temperatures above 250°F. A solution of glycol and water is piped across the diode absorbing the heat and transporting it to the pool’s boiler; therefore, supplying the pool with warm water. The output of solar energy is completely dependent on the weather. New Mexico has such a high UV-index that it is possible that some of our summer days can generate too much energy; causing the pool water to overheat! To combat the occasional issue, B&D installed an 800lb dry cooler on the roof; therefore, allowing the pool to cool the water to the desired temperature before entering the swimming pool. The hope of this project is that solar heating will be efficient enough to save approximately 28,801 cubic meters of natural gas and eliminate 134,272lbs of CO2 emissions annually.
This project resulted in many difficult challenges that B&D had to overcome. It included coordination between multiple subcontractors. B&D had to coordinate with our roofing contractor, DKG to ensure the stanchions for the beams were installed in the correct location. There was no room for error on the stanchions. The stanchions had to be secured to the existing wooden roof trusses. If any stanchion was off by even the smallest margin the entire beam system would have been misaligned. We also then had to coordinate with BES to install the aluminum beams safely and efficiently. The piping for this project was extensive and required exceptional craftsmanship to be able to maintain proper slope while piping around the beams and A-frames. The installation of the 1,800 solar tubes was also a task in and of itself. The tubes could not be exposed to the sun for extended periods of time without glycol in them otherwise they would burst. To work around this, we had to work quickly too fill an entire A-frame with tubes and fill it with glycol immediately to avoid damage to the tubes. We had to continue to do this by valving off each bank one at a time. This ensured all tubes were not exposed for longer periods than what they should be.
This project was a design-bid-build contracted through the City of Albuquerque. During the bid process, the project management team ensured all aspects of the project were taken into account and all subcontractors were fully aware of their scope of work. The project management team used excellent manpower planning and material logistics to ensure this project ran as smoothly and efficiently as possible. Since the work was between multiple trades and subcontractors, proper pull planning technique was used to ensure all trades and subs were aware of each other\’s scopes. B&D also used proper logistics planning to ensure all material was properly staged and organized to expedite the construction process. Proper material handling equipment was used throughout the project to ensure a safe work environment for the construction crew.
This entire project utilized innovative materials. The type of system we used from Kingspan is very innovative and technologically advanced. The vacuum solar tubes that were used are up to 30% more efficient than typical panel solar systems. The system is so efficient a heat dissipater was added into the design for when the solar tubes were collecting too much heat.
This project not only brought state-of-the-art advancement but was extremely sensitive to the environment in offering an energy efficient solution. The purpose of the solar system was to bypass an existing gas fired boiler that was previously heating the pool water. Using this new system, Sandia pool is able to eliminate the use of approximately 28,801 cubic meters of natural gas and 134,272 lbs. of CO2 annually.