Because of the reduction of the world fossil fuel reserves and strict environmental protection standards, one main research direction in the construction field has become the reduction of energy consumption, including materials, technology, and building plans with lower specific energy need, on one hand, and equipment with high performance on the other hand.
The operation of central heating systems at reduced supply temperature results in considerable energy savings. After a thermal rehabilitation of the building, the exceeded surface of existing heaters and the decreased heat load of system can be adjusted to the new conditions by reducing the supply temperature.
This study showed that radiant heating panels works better than radiator heating. In well-insulated buildings, the energy consumption of the radiator heating system is up to 10% greater than that of the floor heating system, which also provided good thermal comfort. In well-insulated buildings, a floor heating system is recommended over a radiator heating system if a heat pump is used as the energy source. However, in this case, a radiator heating system can be designed for low water temperatures because of the smaller differences in the COPsyst (system coefficient of performance) value. There is no reason to use higher than 55/45 °C design water temperatures in well-insulated buildings.
The proposed analytical model of thermal emission for radiant floors was validated by the measured values, and a reasonable agreement prevailed. This model permits the determination of the floor surface temperature at any point on its surface and the emitted mean heat flux.
The floor-ceiling heating system has the best performance in terms of the lowest energy consumption, operation cost, CO2 emission, and the nominal boiler power. In addition, it is important to note that the next best performing radiant system is the system with the wall heating panel. The classical ceiling heating system displays the worst performances in terms of the listed parameters.
The comparison of the room operative air temperatures and the set-point operative air temperature indicates that all radiant panel systems provide satisfactory results without significant deviations.
New investigations should be performed to examine other low-temperature heating systems and their combinations.
Department of Building Services Engineering, Polytechnic University Timisoara, Piata Bisericii 4A, 300233, Timisoara, Romania
In Europe, high energy consumption in the building environment has raised the need for developing low-temperature heating systems both in new buildings and in retrofitting buildings. This paper addressed many different topics related to energy saving in central heating systems with reduced supply temperature and radiant panel heating including floor heating, ceiling heating and wall heating. The paper investigated the performance of these different types of low-temperature heating system using numerical modelling, simulation tools and also site measurements. Thus, energy performance of radiator and radiant floor heating systems connected to a ground-coupled heat pump (GCHP) is compared, as obtained with experimental measurements in an office room. Furthermore, the thermal comfort of these systems is compared and a mathematical model for numerical modelling of thermal emission from radiant floors is developed and experimentally validated. Additionally, a comparative analysis of the energy, environmental and economic performances of floor, wall, ceiling and floor-ceiling heating using numerical simulation is performed. Finally, the energy efficiency of a heat pump in conjunction with a radiator or radiant floor heating system is calculated for different supply, return, and air design temperatures. This study showed that floor-ceiling heating works better than other low-temperature heating systems regarding providing better thermal comfort, lower energy consumption, lower CO2 emission and lower operating cost.Go To Energy Efficiency