Residential hybrid ventilation: Airflow and heat transfer optimisation of a convector using computational fluid dynamics
Hybrid ventilation systems suitable for residential applications are being developed to reduce the energy demand of the housing sector. This paper describes the development and validation of a computational fluid dynamics (CFD) model of a convector unit that is a component of an existing residential hybrid system. The system incorporates a wall-mounted convector unit that controls ventilation airflow rate and air temperature. Airflow is provided by natural driving forces; a mechanical exhaust fan is used at times of low natural driving forces. The CFD model was used to study the aerodynamics and heat transfer processes of the convector unit with the aim of optimising system performance. Based on the modelling results, alterations to the geometry of a set of louvre blades inside the convector unit are suggested. The new louvre geometry prevents the formation of an airflow separation zone inside the convector unit. This improvement reduces the energy requirements of the system by reducing the convector air resistance by 20% and by increasing the thermal effectiveness of its heat exchanger.