Ventilation strategies for thermal performance improvement of an attached sunspace.

In this paper ventilation strategies are examined in order to improve the thermal performanceof an attached sunspace of a two-storey semi-detached house in the area of Athens Greece.The ventilation strategies examined are cross and single-sided ventilation through the verticalwindows of the sunspace. Simulations were conducted implementing multizone ventilationmodel COMIS coupled with the thermal simulation model Suncode. Wind pressure distributionis estimated using a wind pressure parametrical model and results of wind tunnel experiments.It was concluded among others that ventilation strategies appear to be important for the energycontrol and for the formation of the temperature variations in the attached sunspace. Incorrectuse of the windows could turn over the benefits of the bioclimatic design. Keeping the windowsclosed during winter makes the sunspace energy eficient and energy independent inmost hours of the day for almost all of the examined mild climates (Greek and USA cities). Insome of the examined climates the risk of overheating is likely to happen even in winter. Theventilation strategies during the summer period affect temperature variations significantly less,mainly because of the shading devices used to block direct incoming solar radiation. As itswas derived from the thermal balance diagrams in most cases the attached sunspace contributessignificantly to the heating demands of the house.