Kombinerat system för ventilation och rumsuppvärmning
Parameterundersökning i simuleringsmodell för takvärmesystem
A large amount of our time is spent indoors in an artificial climate. To make the experience pleasant there are requirements on the ventilation and the heating system. At the present time the most common form of heating is a radiator system complemented with a ventilation system. A ceiling heating system with combined heating and ventilation can replace the two separated systems. The benefit with a ceiling heating solution is that it saves space since the radiator system is no longer needed. This report aim to evaluate if it is possible to replace a radiator system with a ceiling heating system and maintain a pleasant indoor climate. The ceiling heating system is designed as a comfort module that blows air in four directions, the module is placed in the centre of the ceiling and is heating the room with warm air. The aim of this report is to evaluate which parameters that affects the indoor climate and how these are to be set to make the climate most pleasant. A comparison between the energy efficiency of a radiator system and a ceiling heating system is made.By using the simulation program COMSOL is it possible to evaluate the ceiling heating system and see how the: the angel of which the air enters the room, area of the module that distribute the air in to the room and the temperature of the air entering the room. The climate is evaluated by a number of key numbers which indicates how many of the individuals that feel discomfort for different module set ups. These numbers are plotted with the temperature and different design on the comfort module. The key numbers that will be used is PPD-value, PD-value, radiation asymmetry on a plane and the temperature difference between ankles and head. To be able to compare the ceiling heating systems energy loss through the façade with the radiator systems energy loss a simulation model with a radiator as heating solution were also created. To be able to verify the simulation a lab was executed under similar conditions.The simulations shows that a good indoor climate based on PPD-value is achievable for all different designs of the comfort module with a difference of what temperature that was necessary to achieve PPD=5 %. A problem with the ceiling heating system is that the air does not stir as well as it does when using the radiator system and that the PD-value is too high. There?s a very small difference in energy efficiency between the radiator and ceiling heating system.