Wibke I. De Villiers¹, Calvin L. Pagel², Chad Robins² and Brian Potgieter², William P. Boshoff²
1)  Department of Civil Engineering, Stellenbosch University
Private Bag X1, Matieland, 7602, South Africa
e-mail: wdv@sun.ac.za
2)  Department of Civil Engineering, Stellenbosch University
Private Bag X1, Matieland, 7602, South Africa
e-mail: bboshoff@sun.ac.za

Keywords: alternative masonry units, thermal testing, hot box, R value

Abstract. With the recent publication of the South African National Standard SANS 10400 Part XA: Energy Usage in Buildings, for the first time in South Africa a minimum R-value for walls is prescribed. In addition to this, the research and development of alternative masonry units for the South African low-income housing market is ongoing, in order to reduce the houses’ environmental impact and improve the occupants’ thermal comfort, resulting in masonry walls with unknown thermal properties. It is thus imperative that local thermal testing capabilities are developed and that the thermal performance of these alternative masonry units is determined. This paper reports on the development of a “hot box” thermal testing apparatus, according to ASTM C1363-11, in the Structural Laboratory of Stellenbosch University, South Africa, as well as the subsequent thermal testing of a conventional concrete masonry unit wall and an alternative adobe block wall.