The performance of the comfort conditioning system during the Solar Decathlon was excellent allowing the house to be also awar-ded first prize in the Comfort Zone contest. This contest tested the ability of solar houses to maintain temperature and humidity inside the house within a narrow comfort zone. The interior target range for temperature was between 22.2 C and 24.4 C, while relative humidity had to stay in a range between 40% and 55% for points to be awarded in this contest.
A comparison of the performance of ElementHouse with the second and third place teams is shown in Fig. 26. Both of the other competitors lacked the ability to separately control temperature and humidity. Therefore, both had difficulty in simultaneously controlling temperature and humidity and each had to accept either one or both being out of range. This is likely due to attempts to condition control by dry bulb temperature and with relatively low sensible loads, failing to keep the system long enough to dehumidify. The ability to control temperature and humidity separately allowed the ElementHouse team to have greater flexi-bility in maintaining the required latent and sensible conditions.
Fig. 27. Overall dc power, energy balance, and solar radiation during the Decathlon week.
During the Solar Decathlon, several sets of data were recorded for ElementHouse. Among these data, the overall dc power balance, as shown in Fig. 27, is very useful in showing the performance of the house and its PV electrical system. When the overall dc power balance is positive, the PV arrays are producing more power than the power needed by the house loads. This corresponds to an increase in the energy stored in the battery bank, as can be noted in Fig. 27. On the other hand, when the overall dc power balance is negative, the PV arrays are not producing enough power and the loads extract energy from the battery bank. This of course leads to a decrease in the energy stored.
Fig. 27 shows that the energy balance was negative by the end of the competition week, meaning that the house loads used more energy than what was produced by the PV arrays during that week. This is due to the cloudy and rainy weather on the last two days of the competition week, as shown by the decreasing solar radiation in Fig. 27. Note that, even though the first three days of the competition week were sunny, the solar radiation never got close to a clear sky reading of 1 kW/m2, further impeding the PV arrays from outputting their maximum power. Short term negative energy balance is not a problem as long as there is enough energy stored in the battery bankdthis was the case for ElementHouse prior to the competition week. Furthermore, if the competition was to continue for another week, the energy balance would have easily become positive again. The generally agreed upon goal of a net-zero-energy house is to have zero or positive energy balance over the course of a year.
All the above shows that the University of Illinois student teams sought to prove that addressing the visual and aesthetic does not mean sacrificing price, marketability, and performance. The student team designed and built a house, which demonstrated that solar power is a reliable and affordable energy source when well integrated into the design of a home. ElementHouse proved to be a working prototype for a new-style energy-efficient house in the U.S. By competing in the 2007 Solar Decathlon, the University of Illinois student team achieved its goals in demonstrating to a wide public audience that a solar home can be comfortable, serving many choices of daily activities as it is also an energy efficient and environmentally friendly home. The team also met the great chal-lenge of delivering an affordable and marketable home.
Acknowledgments
We would like to express our gratitude to all the students who helped to design, build, and transport ElementHouse. We want to thank the University of Illinois at Urbana-Champaign for giving us financial support. We are deeply indebted to our faculty advisors, Prof. Ty Newell, Prof. Michael McCulley, and Prof. Patrick Chapman, who guided and encouraged us all the time. 全电气化太阳能房屋英文文献和中文翻译(4):http://www.youerw.com/fanyi/lunwen_41426.html