A study of the effect of zone design parameters on frequency domain transfer functions for radiant and convective systems.
This paper presents a fundamental parametric study on the effect of a number of room design parameters for radiant and convective heating sources as well as solar gains. This study is performed using frequency domain modeling approach by means of which important room transfer functions are obtained and studied. A room is considered with different types of heating (convective and radiative heating sources) and different levels of thermal mass on the floor. The effect of thermal mass and floor covering on the room thermal response considering different types of heating is investigated. The magnitude of the transfer functions between room air temperature and the convective heating source is a determining factor in the room air temperature fluctuations that affect thermal comfort. Also, in the case of radiant heating, the transfer function between room air temperature and radiant heat source can be used to determine the room air temperature swings due to the floor radiant heating source. The sensitivity of the magnitude of the transfer functions versus different values of convective and radiative heat transfer coefficients is studied and compared. This study will guide future model predictive control (MPC) research by means of frequency domain techniques to optimize key design variable such as thermal mass thickness and properties for floor heating and convective systems. It will contribute to linking building design with MPC.