Low temperature heating and high temperature cooling
REHVA Guidebook No. 7
Authors: Jan Babiak (editor), Bjarne W. Olesen, Dusan Petras
Publisher: REHVA (Federation of European Heating and Air-conditioning Associations)
The guidebook describes the systems that use water as the heat-carrier and where the heat exchange within the conditioned space is more than 50% radiant. Radiant ceiling panels are suspended under the ceiling with heat carrier temperature relatively close to room temperature. Embedded systems insulated from the main building structure (floor, wall and ceiling) are used in all types of buildings and work with heat carriers at low temperatures for heating and relatively high temperature for cooling. Finally systems with pipes embedded in the building structure (slabs, walls), which are operated at heat carrier temperatures very close to room temperature and take advantage of the thermal storage capacity of the building structure.
Using a low water supply temperature (of 25 – 40°C) in heating conditions and high water temperature (16 – 20°C) in cooling, allows the possible use of renewable energy sources. In cooling conditions it is also possible to use renewable energy sources, for example ground heat exchangers or rain water ground accumulators.
The guidebook describes the following systems:
• Radiant heating and cooling panels
• Pipes isolated from main building structure
• Thermo Active Building Systems (TABS)
Basic principles of radiant surface heating and cooling
Indoor environmental conditions
System types and estimation of heating/cooling capacity
Control and operation
Energy sources, Installation, Safety
Application of systems in buildings