No abstract

Computational fluid dynamics (CFD) has been used extensively for the prediction of air movement in buildings. In many cases buoyancy forces generated at heated surfaces that dissipate their energy by an interactive process of convection, radiation and conduction dominate air movement. In this work a new method for calculating conjugate fluxes at surfaces involving coupled short-wave and long-wave radiation, convection and conduction is developed as part of the CFD eld problem. The method is based on translating surface radiant exchanges into local volumetric fluxes. Results for a test room with a heated surface compared with data generated within the framework of IEA Annex 20 show that the method produces better results than might be expected from conventional models that use simplified radiant treatments.

This research investigates the overall heating energy consumptions using various control strategies, secondary heat emitters, and primary plant for a building. Previous research has successfully demonstrated that a dynamic distributed heat emitter model embedded within a simplified third-order lumped parameter building model is capable of achieving improved results when compared to other commercially available modelling tools. With the enhanced ability to capture transient effects of emitter thermal capacity, this research studies the influence of control strategies and primary plant configurations on the rate of energy consumption of a heating system. Four alternative control strategies are investigated: zone feedback; weather-compensated; a combination of both of these methods; and thermostatic control. The plant alternative configurations consist of conventional boilers, biomass boilers, and heat pumps supporting radiator heating and underfloor heating. The performance of the model is tested on a primary school building and can be applied to any residential or commercial building with a heating system. Results show that the new methods reported offer greater detail and rigor in the conduct of building energy modelling.