Energy performance of combined radiant and convective systems for energy efficient indoor environment

  • Bolashikov, Zhecho Dimitrov (Project Participant)

Project Details


In Denmark, EU and other countries directives for energy savings are outlined. Substantial part of the energy used in public buildings is for ventilation and air conditioning. Indoor environment becomes important for occupants’ health, comfort and performance. It is a result of ventilation and air conditioning of occupied spaces. At present ventilation systems have poor performance (draught discomfort, poor air quality, etc. are often reported in buildings). Furthermore they are energy inefficient. The reduction of energy consumption in buildings requires development and use of new, energy efficient ventilation and air conditioning systems that create high quality indoor environment.
The proposed research will focus on the energy performance of two new systems for generating high quality indoor environment: 1) chilled beam with radiant panels and 2) chilled ceiling (i.e. radiant cooling) combined with ceiling supply ventilation to distribute air over the chilled ceiling and cool before it flows into the occupied zone. The new systems perform on combined radiant and convective cooling unlike the present available systems based only on the use of convective heat and mass exchange in spaces. It is expected that the use of water based radiant cooling in addition to convective cooling to remove part of the heat generated in spaces will reduce the needed ventilation flow rate and thus to potential energy saving.
The author of this application is involved in an ongoing research at DTU BYG on human response to the non-uniform thermal environment generated by the two systems as a result of the combined radiant and convective cooling. Investigation of the new systems with regard to energy use is also important and is needed to access the system performance. However this research is not included in the limited budget of the human subject study in progress. This proposal focuses on the missing and needed research related to the energy performance of the two systems.
In this research the performance of the chilled beam with radiant panels (CBR) and chilled ceiling combined with mixing ventilation (CCMV) with regard to their energy consumption and resulting indoor climate will be studied and compared with the performance of the chilled beam (CB) without radiant panels which is widely used today. The research will include physical measurements and energy analysis. Test room equipped with the systems and with realistic simulator of solar heat load from windows will be used. The same test room is used in the mentioned above ongoing study to collect human response. Indoor parameters affecting the thermal and air quality performance of the two systems (CBR and CCMV) will be measured and compared to that achieved with conventional ventilation and conditioning systems. The indoor environment generated by the systems will be identified in comprehensive parametric measurements in the occupied zone of the room. Heated dummies, lighting and other heat load will be simulated. Thermal manikins will be used to assess the thermal environment. Energy performance of the systems will be simulated. The results of the measurements will be used for the simulations. The obtained experimental and simulation results will be analyzed in cluster with the human subject response collected in the ongoing project in order to draw conclusions and recommendations.
Important practical implications of this study is that it will define a way for possible savings following the EU directive on energy efficiency through decreased energy consumption in the building sector, help improve the overall indoor environment and last but not least provide the ventilation engineers and consultants with necessary design recommendations.
Effective start/end date01/01/2013 → 28/02/2015