Energy Efficiency Pilot Project Achieves Healthy Results
Encouraging results - including a 20% energy costs saving - have been achieved by a commercial building energy efficiency pilot project initiated at UKZN’s Oliver Tambo building in May last year, industrial sponsors of the project heard at a recent workshop.
The aim of the ongoing project is to determine the impact of double glazed windows and thermal insulation to establish whether they result in a reduction of energy consumption in air-conditioning and associated financial savings. For these purposes only two floors were selected one being totally retrofitted and the other serving as a reference floor as each had similar levels of usage and occupancy.
The four-storey Oliver Tambo building was selected for the project for a variety of reasons including:
• The front section of the building is sun facing and gets direct morning sunlight
• The rear section is shaded and only gets limited sun
• The rear and front offices are separated by a common passage
• There is no restriction for the sunlight onto the front facing offices
• The occupants of the front facing offices complain about the heat
• The occupants of the rear facing offices complain about the cold especially when the front facing offices have air-conditioning on
• Air-conditioning is supplied by a central chiller unit which only runs during the day with individual unit control for each office.
The industrial sponsors and project partners are REHAU, The Cape Windows Group, National Glass, GVK-Siya Zama, Saint-Gobain and Eskom.
Following initial research and based on measurements taken it was decided it would only be necessary to make changes to the sun facing side of the building as the rear facing side was hardly affected by the sun due to the shading offered by the bank and trees at the rear of the building. As such nine sun-facing, first floor aluminium windows were replaced with 20 mm double-glazed uPVC windows manufactured from the UV stable REHAU Ecotec system.
The Cape Windows Group manufactured the casement windows and fixed glazed units, National Glass sponsored the glass for the windows, a GVK-Siya Zama team removed the aluminium windows and installed the uPVC windows, and Saint-Gobain installed ETICS - a polystyrene thermal insulation panel system which was fitted to the outside wall of the installation area.
This specific floor of the Oliver Tambo building was chosen for the energy saving study as it receives direct sunlight, resulting in uncomfortably high temperatures in the offices and subsequent high usage of air-conditioning. In addition it was decided to run the chiller 24/7 instead of the normal daily operation.
The workshop was hosted at UKZN with participants from Eskom, the Department of Energy, SANEDI and the German Embassy representing the German Ministry of Economy and Technology.
The event was opened by Mr Gerhard Gross of Energy Consult and Trade who gave a brief introduction about the project and the different industrial role players. This was followed by the welcome and introduction by Mr M Mfusi of Campus Management Services.
UKZN Energy Consultant, Mr Gregory Diana, said results so far indicated that despite switching to 24/7 air conditioning and with 2014 experiencing much higher daily differential and average temperatures, a 20% energy cost saving was achieved in May 2014.
Diana said measurements of room temperatures on the pilot floor which were retrofitted with double glazed Upvc windows and thermal cladding were shown to have average temperatures lower than the reference floor above it.
A thermal camera was used to compare the heat of an uPVC window with an existing aluminium window on the same side of the second floor. Diana said at an outside temperature of 35°C, the thermal scan of a double-glazed uPVC window read 38°C and an aluminium window 52°C, representing an improvement of 36%.
The University will publish the results of the ongoing project.