Thermalcapacityofindoorroomsurfacesincombinationwithchilled/heatedceilings,floorsandwallsarethebasicprincipalsofastableclimatecontrol.Theroomsurfacesmaintaintherequiredtemperatureforexhibitsbyembeddedwaterpipes(Figs.1and2).Thusallconventionalheatorcolddistributerslikeradiatorsorconvectorscanbeomittedwithregardtoconservatoryreasons.Thematerialsusedareconcrete(ceilings,walls),screed(floors),plasterwithcement,lime,gypsumorclaybinder(ceilings,walls)ormasonry(walls).Clayplasterhasarelativelyhighsorptionrate,whichallowsforstoringexcesshumidity(e.g.fortimesofhighvisitorfrequency).