Effects of Airtightness and Solar Heat Gain Coefficient (SHGC) on Heating Energy Performance of Building Envelope with Trombe Wall

ABSTRACT This study models the retrofit of a Trombe wall to the southern façade of an existing dwelling in Edirne, Turkey. The existing (uninsulated) heating load of the building is calculated as 88 kWh/m2. After the application of insulation, annual heating load decreased to 30 kWh/m2. In addition, annual heating load of the building was calculated as 27 kWh/m2 when a Trombe wall was applied to the southern façade. The study assesses the effects of changes to the building envelope in terms of airtightness and solar heat gain coefficient (SHGC), which influence annual heating load. The effects are calculated according to two scenarios, using Energy Plus and Design Builder software. The two scenarios show 15% and 23% reductions in heating load, respectively, associated with an improvement in airtightness from 1.0 ac/h to 07ac/h and 0.5 ac/h, respectively. An increase from 0.5 to 0.7 in SHGC results in decreases of 4% and 13% respectively in terms of heating load. The findings suggest a Trombe wall represents a practical option for improving energy efficiency by reducing heating load.