The quality of a hydronic energy system isinfluenced by supply and return temperatures.Instead of using the exergy term, a TEA(Temperature and Energy Accumulated) curveis introduced for evaluating an examplifiedplanned 100 GWh district heating systemoutside Oslo.Main focus is on normal running conditionsoff the design point. The following questionswere raised when analyzing the energysystem:how could we make a design that improvesthe use of low temperature energy?is a design with low flow rate, i.e.
The building sector is the first responsible ofenergy consumption in France (about 43%).Improving procedures, simulation tools anddesign methods should go in parallel withefforts to enhance the energy efficiency and tofind optimal design solutions.This paper provides a simplified linearcorrelation method to predict the impact of 11envelope parameters on the heating annualdemand of a single family house in 3 cities ofFrance (Nancy, Agen and Nice).The corresponding model is identified usingthe design of experiments techniques (Taguchitables).
designed "air-curtain chemical fume hood" arediagnosed by using the tracer gas concentrationdetection method. It is found that the air curtainproperly setup across the sash opening allowsalmost no sensible exchange of momentum andmass between the flowfields of the cabinet andthe outside environment. Standard SF6 tracergas concentration measurements following theANSIJASHRAE 11 0- 1995 standard and therigorous EN14175 protocol for both the staticand dynamic tests show extra-ordinarilysatisfactory hood performance. The leakage ofthe tracer gas can approach almost null (< 0.001ppm).
In predicting the cross ventilation rate throughlarge openings, the use of general dischargedcoefficient , values for the conventionalorifice equation is not suitable. 'Interferencecoefficient' which is the ratio of the totalpressure loss coefficient of the room (0 to theconnected value of the pressure loss coefficientof an opening in series (Cn was used. This is akind of correction factor. The laboratory testswere conducted to measure this interferencecoefficient for the various opening sizes androom shapes using scaled models.
Nowadays, due to the energy saving purposes inthe building sector, at new buildings and atrefurbishments, modem closing elements arebuilt-in, with very good thermal insulation andair tightness properties. The frame of theseelements may be from wood, plastic or metal.Each of them has advantages and disadvantages,but during the exploitation the initial value ofair tightness may become higher. Thisphenomenon may appear because of the initialtensions in the materials or due to the failures inthe built-in procedure. The infiltrated air-flowthrough the frame gaps may be significant.
Activated carbon filters have been used forpurification of air and water in industrialapplications. However these technologies have notbeen applied to the non-industrial builtenvironment in general and there is no standard toquantify or to classify the performance of thesesystems for in-duct mechanical systemapplication.
In hot and humid regions, cooling anddehumidification are important issues of inindoor environment. In this study, theevaluation of solar-assisted desiccant airconditioningsystems utilizing periodicallyreactivated desiccant such as desiccant bedsunder hot and humid climates is performedthrough integrated building and equipmentsimulations. As a result, the periodicallyreactivated desiccant air-conditioning systemsperform with relatively higher percentage ofcomfort as well as higher primary energy COPof approximately 6.05 under not extreme highenthalpy conditions.
Thermal mass activation (TMA) can assure, incertain cases, thermal comfort conditionswithout the need of air conditioning systems.Even if other cooling systems have to be used,night ventilation significantly reduces theduration of the working time of additionalcooling systems.The desired night ventilation rate (NVR),could be achieved using either mechanicalventilation, natural ventilation or a combinationof these two methods (hybrid ventilationsystem).In this paper, we will investigate thefeasibility of night cooling using naturalventilation for a residential building in a hotregion of Fran
Traditional and modem natural ventilationtechniques have been integrated in a hybridsystem for a retrofitting of a public building inthe city of Mazara del Vallo (Ttaly). The hybridventilation and air cooling system integrates awind tower, an indirect evaporative heatexchanger, a ground cooling pipe network andventilated fagade. The first idea was to design apassive cooling system inspired to the typicalwind towers of the Middle East, being the areavery well ventilated.
HVAC (Heating, ventilating air conditioning)system is used to keep indoor air quality. Thepurpose of the traditional HAVC system isproviding a comfortable environment andventilating the indoor air pollutants. Recently,with the quality of life increasing, people havemore requests for indoor air quality. However,we found that the HVAC system still stressindoor ventilation, and temperature andhumidity adjusting.
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