Investigation On Energy Saving And Indoor Thermal Comfort For Cooling/Heating Radiant Air Conditioning

The characteristics of air conditioning method by radiation heat transfer are smallvertical temperature grade,high thermal comfort and energy saving.While the systemeconomy is rather poor,if employing two suits of roof and floor systems for airconditioning in summer and heating in winter respectively.Therefore,considering thedemand of comfort and energy saving of interior buildings,this paper presents theresearch of utilizing a same suit of system of side wall radiant panels for air conditioningin summer and heating in winter simultaneously,which is significantly important toachieve energy conservation and emission reduction and the demand of people to indoorcomfort.Sensible heat loss and latent heat loss of indoor human body interact withsurroundings by convection and radiation.For side wall radiation,the influencing factorsof indoor comfort include vertical air temperature difference and ununiformradiation.Employ vertical air temperature difference indicators to evaluate thermalcomfort of human body.The amount of heat exchange can be calculated by linearizationmethod of ASHRAE.Taking an office of Baoding city in Hebei province,employing k-εdouble equationsmodel and DO radiant heat exchange model,this paper utilizes commercial software toanalyze radiant cooling and heating.The simulation result shows that the verticaltemperature difference by using roof radiant cooling and floor radiant heating can satisfythe demand of indoor human body both in summer and winter.Nevertheless,roof radiantheating and floor radiant cooling with the same parameters can’t meeet thedemand.Though indoor space can achieve the demand of cooling and heating by addingthe area of radiant panels,it still can’t reach to thermal comfort due to too large verticaltemperature difference.Indoor temperature and vertical temperature difference canbasically meet the demand of indoor human body to comfort in summer andwinter,arranging the radiant panels on the location of center on the east and west sidewalls.To optimize the arrangement of side wall radiant panels,this paper presents thesimulation of arrangements of radiant panels in the center and center on the lower of theeasten and westen side walls.While both indoor mean temperature and verticaltemperature difference can satisfy the demand of cooling in summer and heating inwinter,the indoor temperature distribution is still ununiform.For this reason,give ascheme of arranging the radiant panels on the location of easten,westen and southen sidewalls.The result of numerical simulation shows that not only the indoor average temperature and vertical temperature difference can meet the demand of cooling insummer and heating in winter,but also the indoor temperature distribution is moreuniform by employing this scheme.