Investigation of the timetabling-based smart energy managment system for educational buildings and its implementation perspectives

Abstract

Buildings consume about 40% of global energy and 25% of global water, and are the source of about one-third of GHG emissions (UNEP, 2009). In the UK, the share of buildings in energy consumption is 44%, which is higher than that of transport (34%) and industry (22%). As the constraints on natural resources grow critical over time, saving energy through sustainable engineering methods becomes essential very much in demand. Energy consumption in educational buildings is affected by group events such as lectures at classrooms ’timetabling and examination, etc. and can be reduced by energy saving strategies designed specifically for such built environments. Heating, Ventilation and Air Conditioning (HVAC) in educational buildings represents the largest component of the use of energy (approximately 40%) (Crawley et al. 2008). Educational buildings involve highly variable occupancy patterns and often incorporate a wide range of zone types that further broaden their operating conditions (Martani, 2012). This research aims to focus on reducing the consumption of heating energy within lecture rooms, as this is an area largely influenced by the occupants’ behaviour and lecture timetabling. The key objective is to design and assess the long-term impacts of a number of novel energy saving strategies by use of timetabling data, while guaranteeing that all balanced requirements are met. A dynamic, steady-state simulation modelling of building energy performance is carried out in which all the heat transfer and heat balance analysis are undertaken on an hourly basis and the results over a long period of time are generated. Twelve lecture rooms at Brunel university London were modelled and simulated to evaluate nine various energy saving scenarios against the current situation (baseline) with regards to the heating system. Six years of weather data were used to incorporate weather variables over the years. Nine scenarios were associated with four groups of improvement strategies that have been developed in this research. The results on the ‘occupancy based scenario informed by timetable’ were promising in terms of the total annual heating load. In fact, the saving impact of this scenario is even greater than that of using triple glazed windows. This research also suggests that 5oC can be an optimum set-back point within the context of educational lecture rooms in cold climates similar to that of the UK. Furthermore, on the energy-aware timetabling strategy, the ‘No Late Evening Bookings’ scenario can be more promising in comparison with the ‘No Early Morning Bookings’ with regards to the total annual load performance. This suggests that room bookings on early mornings rather than late evenings, should be recommended from the energy saving perspective.