Research continues to present the many reasons why clay brick construction, so widely applied in South Africa for house construction, deserves its pre-eminent status. Equally interesting is the finding that clay brick internal partition walls add so much more to the thermal comfort equation of houses than previously thought.
The research findings, a product of 8 years of empirical study at the University of Newcastle’s Priority Research Centre for Energy – where the building modules comprising different wall construction types were continually measured under real life conditions under both free floating and controlled internal conditions – have comprehensively shown:
- Insulated lightweight building (high thermal resistance [R-value] with no thermal mass in the walls) as the worst performing in all seasons.
- Brick veneer (brick applied to the external skin of the external wall) performed better than the lightweight.
- Insulated cavity brick performed the best.
As shown in the graph, the lightweight module responded immediately to the external solar radiation that was incident on the external surface. Inhibiting the performance of the lightweight module was its lack of requisite thermal mass to assist in maintaining adequate thermal comfort.
The net outcome was that the insulated lightweight module exhibited greater variations in internal temperature and little thermal lag. The lightweight module, notwithstanding its high R-value, had the highest temperatures during the day and the daily swing in temperature was also consistently the highest. This necessitated the energy consumption of the lightweight module to be higher to counter the large daily temperature swing.
While these empirical research findings correlate with all thermal modelling studies that have used ASHRAE and Agrément SA compliant software, additional research at the University of Newcastle has now gone a step further to show clay brick internal partition walls as affording further thermal enhancement over lightweight internal partition walls for houses.
Specifically it was found that after introducing more thermal mass in the form of internal walls to the 6m² x 6m² modules comprising slab-on-ground, significant north wall glazing, the following additional reductions in energy consumption were realised:
- Insulated cavity brick – 6%
- Insulated reverse brick veneer – 8%
- Insulated lightweight – 20%
While internal partition walls in brick afforded improvements in all instances, the effect of the additional thermal mass was found to be less prominent than for the lightweight walled building, as the masonry walled modules were already benefitting from lower energy demand from thermal mass that brick walls provide.
To better understand why double skin clay brick construction with the appropriate use of resistance between the brick skins for the climatic zone is the real deal for achieving optimal energy efficiency in climates akin to South Africa and the ‘extra’ value clay brick partition walls provide, go to www.thinkbrick.com.au and download “Energy Efficiency and the Environment, The case for clay brick, Edition 4” and “A Study of the Thermal Performance of Australian Housing Priority Research Centre for Energy , University of Newcastle”.
According to Corobrik the bottom line for clay brick construction in the South African context is that it does the job properly and efficiently, providing excellent all round performance.
