Experimental Study On The Indoor Thermal Environment And Lying Human Body’s Thermal Comfort Of Double-sided Radiant Cooling And Heating System

With the aims of energy conservation and pursuit of comfort, a lot of scholarsdevote themselves to the study of the relevant technologies related to radiant heating/cooling system and their application in practical projects, as well as the researchesconcerning human body’s thermal comfort in office buildings. However, there are only ahandful of researches which concentrate on the thermal comfort of such kind of peoplewho are often in the state of sprawl. especially in a situation of single or double-sidedradiant heat transfer system.Aim of this research paper was to study the characteristics of indoor thermalenvironmentand lying human body’s thermal comfortboth in empty rooms andbedrooms in a situation of double-sided radiant heating/cooling system, with thefundamental purpose of giving inspirations to the design and application ofdouble-sided radiant heating/cooling system in practical projects, e.g. hospital buildings,bedrooms, hotel buildings, etc.In this research paper, we choose winter and summer to make experimentalmeasurement of empty rooms and normal rooms which have furniture inside of twobuildings respectively. The test subjects are required to make the thermalcomfortexperiment in rooms which have furniture inside. Consulting the definition andcomputational method of meanradiant temperature and operative temperature, this paperpresents the computational formulas of mean radiant temperature and comprehensivecharacteristic temperature available to both the upper place and the lower place in aroom which has furniture inside.Through the experimental data analyzed the uniformity of indoor air temperatureand the envelope surface temperature,And also the results show that there exists astrong linear relation between the indoor air temperature and the mean radianttemperature in an empty room, while the indoor air temperature and the mean radianttemperature of the upper place and the lower place in a room which has furniture insidehas a kind of strong dualisticlinear relation. Moreover, in order to simplify thecomputational formulas of mean radiant temperature, the temperaturedifference ofindoor envelop enclosure surface temperature and indoor air temperatureinthecontextofradiant heating/cooling system is also explored.This paper analyses the key factors that impact the experimental measurement of lying human body’s heat comfortthrough the questionnaire investigations made by thetest subjects about the heat comfort in the lying state in the context of different timeranges and different heat environment. Accordingly, as far as healthy people who arewearing long-sleeved pajamas and lying on the bed（also covered by quilt in winter） isconcerned, in summer amd winter, the mean radiant temperature above the bed whichmakes them feel comfortable is within the scope of26~29℃、17~20℃, the airtemperature is within the scope of25~28℃、16~19℃, and the comprehensivecharacteristic temperature,26~28℃、17~20℃.Last，this paper put forward the simplified computational formula of radianttemperature and supply-return water mean temperature in radiant coils.With the aid ofthe experimental conditions of this pape, verified the accuracy of using the simplifiedcalculation formula to calculating water temperature.And in this way we can simplifythe relationship between radiant temperature and water temperature, thus thesuitablewater temperature which a comfortable indoor thermal environment requires canbe estimated.