In recent years, in the quest focused about energy conservative building design, as a high efficiencyair conditioning scheme, the variable air volume (VAV) systems owe their growing popularity in heating,ventilation and air conditioning (HVAC) applications. This paper reports the simulation study toinvestigate the inherent operational characteristics of direct expansion (DX) VAV air conditioning (A/C)unit when the supply air fan and compressor speeds are varied based on the thermal load persisting inthe conditioned space.
Field measurements of the indoor climate have been carried out in 128 lightweight timber-framedetached houses in Finland and in Estonia during the years 2002-2005. The temperature and relativehumidity were continuously measured in bedrooms, living rooms and outdoors for each house at 1-hourintervals over a 1-year period.
This paper reviews the previous attempts to evaluate the Indoor Air Quality (IAQ), investigatespreviously proposed IAQ factors and analyses the evaluation methods of these factors. The presentwork introduces, also, a new hypothesis of the optimum HVAC airside system design of the surgicaloperating theatres to achieve the comfort and hygiene levels. The present work is devoted to proposeand formulate a new scale capable of adequately evaluating the airflow pattern in the surgicaloperating theatres. The proposed new scale is proposed to cover the local and overall air qualityevaluations.
Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfortand hygiene conditions. This paper utilizes a 3D Computational Fluid Dynamics (CFD) model toassess the airflow characteristics in ventilated and air-conditioned archeological tombs of EgyptianKings in the Valley of the Kings in Luxor, Egypt .
In this paper, the indoor environmental quality for the commuter train space was analyzed for assumingthe load factor of seat capacity to be a parameter of analysis. Especially flow fields, temperature and airquality distributions in vehicle space were analyzed by using CFD technique. Furthermore, it reports onthe result of examining the controllability of indoor climate in the vehicle when the displacementventilation system was applied in it.
Assumptions of productivity costs related to the outdoor supply airflow rate and indoor temperature canbe made based on a number of recent studies. A life cycle cost (LCC) computer program for indoorclimate systems based on Swedish conditions was developed and used to compare and optimizedifferent indoor climate systems. A productivity cost related to the outdoor supply airflow rate and theindoor temperature according to the recent studies was assumed.
We already have had theoretical model to predict temperature and humidity variations in a room. Manyworks have estimated the accuracy of the numerical model, but they might be influenced by the airmovement. Thus, theoretically the temperature and humidity variations should be solved with airmovement in a room. In this paper, I calculated the minute temperature and moisture distributions in aroom which has the moisture buffering effects by the porous walls. The room space is regarded asrectangular box which has two hole, inlet and outlet for ventilation.
Energy conservation is one of the key issues for environmental protection and sustainabledevelopment. Currently, about 17% of the total energy is being consumed for heating, ventilation, airconditioning (HVAC) and refrigeration in Hong Kong. Therefore, energy saving in the HVAC systemsof buildings is an important topic. In this paper, a study on the energy saving in a hotel HVAC systemwas carried out. The cooling load features of the hotel were analyzed. Retrofitting strategy of theHVAC system in the hotel was then designed.
By natural ventilation, the air rate varies randomly. Therefore, it is difficult to evaluate the naturalventilation performance due to insufficient measured data. In the present work a complex office buildingwas taken as a study object for the experimental investigation. A measurement technology isdeveloped in this work for the assessment of the natural ventilation performance in the building.
The distribution of indoor airflow velocity by cross ventilation is influenced by the regional climateconditions, and the location as well as the shape of the building. In this study, CVDHI of 25 cases tochange the number and position of openings at 842 cities in Japan are calculated for the simple housemodel. The results indicate that CVDHI increases relatively in every case from the south to the north ofJapan.
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