Why indoor temperature is higher then outdoor temperature?
I have measured indoor temperature of a simple closed room dimension of 4m x 4m x 3 m without any window and door and with walls are made by bricks and plaster and roof by concrete using the Energyplus 8.2. I input the weather data for Sydney and simulated from 1th Jan to 5th Jan. I find that the indoor temperature (room temperature) is always higher than the outside temperature. For example, when out side temperature is 32 degree C at that case indoor temperature is 41 degree C. Is the simulation results correct or not? If yes, how it possible to inside room temperature is higher then the outside temperature? How can I optimize the inside temperature?
That is the effect of thermal mass. Thermal mass stores all the energy and will re radiate it into the room. all the heat energy will be piled up (Stored) and it will be releasing all the energy once it is done with the storing. it is irrespective of the outside temperature. try to keep higher thermal mass and then you will end up seeing high temperatures during night time. if you put low thermal mass, you will end up seeing high temperatures during day time which can be higher than the outside air temperature and
That could also just be that you have high internal loads and no ventilation.