Cooling: Combining Vegetated roofs with Night Ventilation

This paper describes the effects of green roofs and night ventilation on internal temperature of buildings using test cells with different configurations. Three cells are used in these tests, all of them cooled with night ventilation, one with an insulated green roof, another with an uninsulated green roof and another with a conventional code compliant insulated roof. Several series are performed and results indicate that the test cell with the green roof and no insulation performs better than the test cell with the insulated green roof and the conventional insulated roof. Thus, in warm climates with cool nights, when it is possible to use night ventilation to passively cool a building, it is preferable to have the soil mass coupled with the inside of the building instead of having additional insulation separating this mass from the space. Equations are derived from the experimental work that permit to calculate internal maximum temperatures as a function of outdoor maximum and mimimum temperatures with different glazing to floor ratios