A numerical model of room temperature control based on the operative temperature is developed for a room with radiant ceiling heating. A room thermal network model that accurately represents thermal mass in all walls and room interior radiation exchanges is employed for estimation of Laplace transfer functions that are subsequently used for control studies. First, an efficient technique for calculating the transfer functions for the effects of heat sources and temperature changes on operative temperature is described. Then, a feedback proportional control system that controls operative temperature is compared with one that controls room air temperature. Numerical simulations indicate that for equal thermal comfort the response time is significantly lower for control of radiant ceiling heating based on the operative temperature as opposed to the air temperature. Preliminary experimental results also indicate improved thermal comfort based on the operative temperature.

KEYWORDS: radiant heating, ceiling heating, room temperature, controls, rooms, operative temperature, calculating, comparing, thermal comfort, air temperature, heat flow, energy sources