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A Workplan to Analyze the Energy Impacts of Envelope Airtightness in Office Buildings | NIST
US. oi%ce buildings consume approximately 1.2 EJ (1.1 Quadrillion BTUS or Quads) of energy, 0.72 EJ (0.68 Quads) of which is associated with space heating, cooling, and ventilation. These estimates, and other analyses of energy consumption in oillce buildings, are based on building energy analysis programs such as DOE-2. These analyses have been helpful in identifying opportunities for energy efficiency, developing building energy efficiency standards and predicting future energy consumption levels. Although these programs contain sophisticated models of heat transfer and HVAC system performance in buildings, they are acknowledged to have shortcomings in accounting for the energy associated with building airflows, particularly infiltration of outdoor air through leaks in the building envelope. These airflows, and their dependence on weather and ventilation system operation, are more complex than the models used in these programs. The simple models of infWration, ventilation and interzone airflows that are used in these programs do not enable the analysis of the energy consumption wsociated with building airflow or the impact of options that may reduce this energy consumption, such as increased envelope airtightness or better control of ventilation system airflow rates. This report describes the impact of building airflows on energy consumption in multi-zone buildings and the analysis approaches that can be used to account for the energy associated with these airflows. Plans to link a multi-zone network airflow analysis program with a building energy analysis program are discussed. An initial estimate of the energy associated with inilltration in US. office buildings, based on a simplified analysis approach, is presented. This estimate reveals that infiltration in U.S. office buildings accounts for 0.074 EJ (0.07 Quads) of space heating energy use, which is 18°/0of the total heating energy use, and 0.0025 EJ (0.0024 Quads) for cooling, which is 2% of the total.
The Inca Occupation of the South Coast of Peru
like the others, however; it forks into several nearly parallel ravines of which the largest are Huayuri, Rio Grande-Palpa, Ingenio (called Collao in ancient times), Nasca proper (the ancient Caxamarca), Taruga, and Poroma. Due to peculiarities of the local topography, the irrigated areas in Ica and the ravines of Nasca are located inland, at the foot of the mountains, rather than at the mouths of the rivers as is more usual in Peruvian coastal valleys. No sharp natural or cultural boundary separates the valley of Chincha from the valleys of Cafiete (ancient Huarco and Runahuana), Asia, and Mala, the next valleys going up the coast to the northwest. At the other end of the area we are considering, however, there is a sharp break; beyond Yauca the Andean foothills reach out to the sea, natural conditions are quite different, and there are important differences in the archaeological picture as well. The historical sources which mention the south coast are not particularly helpful, except in so far as they provide us with a few dates. To begin with, no chronicler gives an explicit account of the political organization of the south coast at the time it came into contact with the Incas. It can, perhaps, be inferred from Cabello Balboa's statements about common policy toward the Inca invaders that there was some sort of political connection between the valleys of Mala, Cafiete, and Chincha, but the connection need have been no more than a temporary military alliance. Cabello makes no mention at all of Pisco. The valleys of Ica, Nasca, and 125