IEQ And HVAC

The vocabularies "environmental pollution" and "environmental protection" have been widely used. The environment problems are paid worldwide attention. People are facing a lot of serious environmental problems such as global warming, ozone layer breakage, human resources drying up, atmosphere and water pollution etc… All of these threaten mankind survival. In recent years, with the development of high-tech and improvement of living standard, the interior environmental quality problems have get more and more consideration. People spend more time in door than out door, so as a part of the environmental problem, interior environmental quality greatly affects the human life and development. The interior environment quality includes factors like interior air quality, comfortable degree, noise, social psychological stress, social work pressure, workplace background etc., which affect people physiologically and mentally in a single or a Comprehensive way.There are a lot of methods to create the high interior quality. Heating, ventilation and air condition (HVAC) is an important way to realize the target, and the development of HVAC assures the realization of high interior environment. The combination of interior air quality and the technology of HVAC play an important role in the effective usage of environment and energy too. But HVAC aroused the other problems. The HVAC equipments consume lots of energy and utilization of the energy is main reason of environmental problems. On the other hand, long period staying in indoor environment easy to arouse such symptoms as stuffy, headache, drowsy, which are so called "synthesize symptom of sick building". It is main point of the paper that how to improve interior environment quality to meet the humans need with the help of HVAC and how to coordinate relations of the interior environment, HVAC technology and effective use of energy.There are many factors influencing the indoor environment quality, but hot and wet environment, interior air quality, interior wind velocity and interior noise has close relation to HVAC. Interior air environment quality study pays more attention on warm comfort feeling of the human. Evaluation indexes of the warm comfort are predicted average evaluation (PMV) and predicted dissatisfied percentage (PPD). There are six factors affect warm comfort of people: Interior air temperature, relative degree of humidity, inside temperature of construction, interior air speed, human body metabolism rate, clothing condition of the people. According to the calculation of PMV and PPD about some air-conditioning room of summer, this paper defined indoor humiture scope of thermal comfort. By means of the result of PPD, analyzed that temperature is different with humidity on thermal comfort. The interior air quality is a part of the interior environment quality. Before, people almost took the interior air quality as a series of pollutant density index. In these years, according to the definition of the standard made by the American Society of Heating and Air Conditioning Engineers (ASHRAE), good interior air quality should be "there is no known pollutant reached the index that authority organization defined, and great majority people(≥80%)in the air do not complain about the it". This definition improved people's recognition of interior air quality, which combined objective evaluation with the subjective evaluation. According to this definition, the density of the interior pollutants can be taken as the objective evaluation index of the interior air quality, which includes grain pollutants and harmful fume. The pollutant density index of interior air quality pointed is not traditionally permitted density index by hygiene safety branch, it reflects it's chronic and latent influence on person when the person works long time under such environment. The quantity of fresh air volume can control the quality of the interior air. The grade of air filter can control interior air clean grade.Because of usage of the facilities of ven...