Determining Active Thermal Capacity

Energy efficient building standards tend to focus on the thermal resistance requirements of the envelope, whilst the benefits of the thermal capacity present in masonry construction, are less highlighted.

Developing the SANS 204:2010 standard for Energy Efficient Buildings in South Africa, requires research to define the “deemed to satisfy” thermal properties of external masonry walls. Using simplified CR Method equations, with comfort theory amplitude ratios, the required active thermal capacities of the building structure are calculated.

A novel algorithm calculates the actual active thermal capacities of insulated masonry walls.

Simulation models predict energy use and life cycle cost for building occupancy types, correlating well with the CR-value of a masonry wall. Minimum CR-values for masonry walls are proposed for inclusion in the SANS 204:2010 standard.

Authors

PROF. DIETER HOLM
Department of Architecture, University of Pretoria
Vice-President for Conference, International Solar Energy Society (ISES)

HOWARD C. HARRIS
Technical Director
WSP Energy Africa

WAYNE BURTON
Technical Chairperson
Clay Brick Association of South Africa