Abstract
M.Tech. (Architectural Technology)
It is estimated that commercial buildings are responsible for 5.4% of worldwide Green House Gas (GHG) emissions through their construction and on-going operation. In developed countries this figure can go up to 30%. The environmental control industry is one of the large consumers of this energy. Heating, ventilation and air conditioning (HVAC) contribute approximately 15% of South Africa's current peak electrical demand consumption according to Eskom (the South African electricity utility). The purpose of
this dissertation is to analyse and evaluate methods to reduce the energy consumption of the HVAC system in a commercial office building. This encompasses careful building design to reduce heat loads and promote the circulation of fresh air; the use of energy-efficient air-conditioning systems and the incorporation of materials and technology to reduce energy consumption. This will be based upon a case
study of the new SANRAL (South African National Roads Agency Limited) head office building in Val-DeGrace, Pretoria. A deductive research approach will be followed. The as-designed Actual Building is modelled with the
appropriate energy modelling software and its annual energy usage is obtained. A benchmark based Notional Building complying with SANS 204:2008 criteria of the same size, shape, location and operational schedules as the Actual Building is also modelled and its energy usage results compared to
that of the Actual Building. This comparison will determine how energy efficient the Actual Building's HVAC system is compared to a conventional Notional Building. Quantitative data collection is performed by empirical measurement of the energy usage of the as-built Actual Building. The raw data (power usageofthe HVAC system) is measured by Schneider Electric PM9c™ power meters located in the HVAC distribution boards of the building. This raw data are collected by Schneider Electric's ION Enterprise'
power management software which has a user friendly interface from where the data can be downloaded. The power management software is connected to an ANDOVEWM Building Management System (BMS). Due to commissioning procedures and the timeframe at hand for the completion of this dissertation measurements could only be taken over a 7 month period. Operational data were measured from July 2011 to March 2012 thus accounting for summer, winter and a seasonal changeover period. The modelled energy usage results of the as-designed Actual Building are compared to the
measured energy usage data obtained from the as-built Actual Building. This comparison serves to evaluate the accuracy of the software model...