The Santa Clara Community Recreation Center is one of the first new, large buildings in the world to be both heated and air conditioned using energy from the sun. Located in the city's 52-acre Central Park at 969 Kiely Boulevard, the 27,000 square foot building is designed to meet a wide variety of community needs, and is administered by the city's Parks and Recreation Department. When the building was being planned in 1973, the city instructed architect David C. Thimgan to make provision for the possible solar heating of the building. Simultaneously, Lockheed Palo Alto Research Laboratory began assisting the city in the design of a solar system and the development of possible sources of federal funding. Santa Clara was interested in solar energy technology because of its long history as a municipal utility city and because of its desire to reduce the building's operating costs over its expected long life. Ground was broken for the Center in April, 1974, and in November of that year the city was successful in obtaining a grant from the National Science Foundation to partially cover the added cost of the solar energy system. When the federal Energy Research and Development Administration (ERDA) was created in 1975, responsibility for the project was transferred to that agency. Additional financial support was provided by the American Public Power Association. Four hundred thirty-six high performance solar collectors (7,085 sq. ft.) manufactured by AMETEK, Inc. are mounted on the south side of the building and over the auditorium at an angle of 18 degrees up from the horizontal. Water containing anti-freeze and corrosion inhibitors is pumped through the collectors at the rate of 140 gallons per minute. The collectors contain a copper plate with integral water passages and two sheets of glass to reduce heat losses. A special black coating of the copper plate further increases the performance of the collectors. During the summer, the collectors produce water at temperatures up to 220° F. These high temperatures are required in order to drive the absorption water chillers which provide cooling to the building. If allowed to run dry in bright sunlight, the collectors can approach temperatures of up to 450° F. Much of the solar installation work on the project was done by field crews from Santa Clara's Utility Department. This included installation of the solar collectors and the two underground storage tanks-one for 10,000 gallons of hot water and the other for 50,000 gallons of cold water. The two storage tanks allow the building to be heated and cooled at nights and on cloudy days without having to turn on either the backup boiler or the two 25-ton lithium bromide absorption water chillers. Computer simulations performed by Lockheed indicate that the solar system will provide 84 percent of the building's heating, 65 per cent of its cooling and 80 per cent of its total heating and cooling energy requirement on a year-round basis. The remaining energy requirement will be met by the backup boiler and the electrically-driven pumps and fans. In the heating mode, energy which is absorbed by the solar collectors is transferred either to the hot water storage tank or to standard fan coils distributed around the building. Air is blown across these units and into the rooms in order to provide heating. When there is not enough sunlight available, energy can be transferred from the hot water storage tank or the boiler can be activated. During some periods of the year the hot water tank will actually boil and steam will escape through the vent. During four to six months of the year there is enough solar energy available to drive the Arkla absorption chillers. These devices produce cold water at temperatures down to 45° F. and are "powered" by hot water produced by the solar collectors. When the energy is available, the chillers are turned on to cool off the water in the cold water storage tank. When there is a need to cool the building, cold water is brought in from the tank and circulated through the fan coil units. If necessary, the boiler can also be turned on to run the chillers. The operation of the entire system is completely automatic for both heating and cooling so that building occupants never need to operate" the system. However, it has been designed to be extremely flexible in operation so that experiments can be run to determine the optimum method of system operation. To assist in this research, a computer is installed in the rear lobby of the building where it is open to public view. The computer monitors the performance of the heating and cooling system and gathers such data as system temperatures, whether the pumps and boiler are on or off, electricity consumption, valve position and weather conditions. This data should assist designers of future solar heating and cooling systems in choosing appropriate components and efficient system designs. Data collection and analysis is being done by students and faculty members from the University of Santa Clara. The total value of the solar project is almost $1 million with approximately $550,000 devoted to actual building improvements. Outside assistance consists of grants of $667,821 from the Energy Research and Development Administration and $5,000 from the American Public Power Association. The Center is Santa Clara's largest recreation building and it is open to the public six days per week. There are a number of educational solar energy displays in the building and courses on solar energy technology are periodically offered by the city's Parks and Recreation Department. COOLING SYST Other Santa Clara Solar Projects... Santa Clara has expanded its solar energy program to include a number of applications beyond the Community Recreation Center project. For example, the city is investigating the feasibility of a utility's offering solar systems in the same way that it offers other utility services. A Solar Division has been created as part of the city's Water Utility Department and swimming pool owners in the city can now sign up for solar heating just as they can contract for electric or water service. The city then installs a solar heating system and a service charge appears on the customer's regular monthly utility bill. Systems have been installed on pools ranging from backyard size through apartment and condominium pools, and, in most instances, the individuals are paying less in solar rental costs than they formerly paid for gas heating. With the assistance of a grant from the Department of Housing and Urban Development, Santa Clara has installed solar systems to provide heating and hot water for five new homes in the city. As with the pool installations, the systems are city property and the customers pay a monthly service charge. The systems are being monitored closely to determine when the city can offer such systems at a price competitive with conventional energy sources. The only form of heating for the 3,800 square foot swimming pool at Santa Clara's new Montague Swim Center is solar heating. Combined with energy conservation measures such as covering the pool when it is not in use, it was determined that solar heating would be perfectly satisfactory during the six summer months the pool is open each year. Santa Clara is also planning to solar heat its famous International Swim Center. The cost to heat the over 19,000 square feet of pool area with natural gas has become enormous and the city plans to cut this cost with almost 13,000 square feet of solar collectors mounted on top of a canopy over the spectator stands. When completed, this will be the largest solar swimming pool heating system in the world. The city will probably offer retrofit solar systems for domestic water heating in the near future. Preliminary studies by the city's Solar Utility Division indicate that these are almost competitive in monthly cost with conventional electric hot water heaters. 1 Solar Utility 2 Solar Heated Homes 3 Montague Swim Center 4 International Swim Center |