It’s very common for buildings to be lit up, heated and cooled even when there is nobody using them.
This may be an obvious area to consider when reducing energy costs, but can be complicated; on a busy campus, buildings are in use and empty at varying times of day over the course of a week or a term, and patterns of use can change often.
Relatively simple changes can help reduce energy use, like presence-detection lighting in corridors, but bigger savings can only be made by addressing the overall complexity of building use, and how this use might be tracked and heating and lighting tied to it.
There are various ways that IT can improve the efficiency and effectiveness of university and college estates, and reduce the energy consumption and carbon emissions of buildings.
Making the most of building management systems by refining what is measured and how often, and integrating the systems with administrative and academic systems, can open up a way for more flexible control of heating and lighting based on building use. For example, timetables could be reorganised to minimise energy peak use while still meeting educational objectives, or heating could be automatically turned off when rooms are not in use.
Case study: multiplying savings in Aberdeen
When major refurbishments are undertaken the University of Aberdeen takes the opportunity to install energy-efficient equipment and controls. Changes can be small, but when multiplied up over the university they are significant.
Some sample wastage costs from the university show how change can make a difference:
- Leaving lights on in a large lecture theatre overnight - £20
- Leaving a 10kW furnace on for 24 hours when not needed - £29
- Leaving 20 windows open during the heating season - £388
Automatic lighting control
The introduction of automatic lighting control at the university has been a major benefit.
For corridors, presence detection is used; the sensor detects a person entering the area and switches the lights on for a pre-set period. For offices and rooms, the user can turn on the lights, or leave them off if desired. If the lights are turned on, the presence detection also comes on. If the person leaves the room and does not switch out the lights, the system will automatically turn them off after a pre-set period.1
Making buildings more efficient is about bringing together IT, measurement and building use.
Like most institutions, Leeds Beckett University has a mixed inheritance of building types and ages, with room climate controls ranging from simple household type radiator heating systems through to state of the art building management systems, combining heat, air conditioning and ventilation with fine control and feedback.
The Jisc-funded heat and light by timetable project at Leeds Beckett aims to integrate the separate heating/cooling control and timetabling systems to ensure that heating or cooling is provided only at those times where rooms are in use, and allow the environment to be less comfortable when rooms are not in use.
"Our work has shown that it is possible to derive the control patterns in a way which allows us to directly link one university system (our timetabling program) with another (the building management system). Using standard SQL as our core 'translation' system means that our approach should be widely useable."
Professor Colin Pattinson, Head of School of Computing, Creative Technologies and Engineering at Leeds Beckett University and project lead
Leeds Beckett plan to use their occupancy data for other purposes as well: controlling other functions such as lighting is obvious; they may also link with security and other monitoring tools.
The work by Leeds Beckett also revealed that in practice, there are additional complications to address when controlling heating and cooling cycles intelligently:
- Heating or cooling a space takes time, therefore you need to start the process ahead of occupancy (likewise, you can usually turn off before the end of a session)
- There is a minimum time between successive occupations below which it makes no sense to make any changes
- Each building control typically covers a number of separate rooms, therefore any use of any room in that coverage area will give rise to the need to control the whole set of rooms
- Settings (including on/off delays) will vary according to external variables like outside temperature, and internal factors like room size
Monitoring activity patterns
One of the issues that the project at Leeds Beckett surfaced was that of the differential pricing of electricity by power suppliers. The cost of energy is varied at half-hourly intervals throughout the day - and that can give rise to an apparent paradox where falling consumption results in higher costs.
This is particularly evident in the mid / late afternoon period, as the number of separate activities within the university falls towards the end of the working day and demand drops as a consequence of electrical equipment being powered down. However, the late afternoon is the very period when energy cost is increased by suppliers to control demand and manage their generation activity. So the cost of the electricity doubles, even as the demand is falling.
This gave the university a strong incentive to examine the occupancy patterns in this late afternoon/early evening period.
A building management system (BMS) can work on a number of levels. It can monitor, control and automate facility operation and usage (such as heating, cooling and lighting) in your building.
Many institutions have their buildings connected to a BMS, but how well it is monitored, how the data from it is used, or how it is programmed to manage and automate building controls, may vary widely.
People are important too. You need staff on the ground collecting and analysing data and reporting back; this will enable you to make the right decisions about building efficiency based on those data.
There is a history of building management systems being proprietary, stand-alone and unable to talk to each other. Such systems may need dedicated networks, and special interfaces to talk with other systems.
More modern intelligent building systems are now being used alongside, that integrate using internet protocols and open standards such as DeviceNet, SOAP, XML, BACnet, LonWorks and Modbus, and often include or take the form of ‘smart devices’, allowing easy and constant remote access to the system.
Building management systems are often in their own silos with different front ends and their own discrete controls, and integration between legacy and new systems can be difficult, with issues including firewalls, routers and network construction to consider. These are traditionally IT issues, but with the development of the modern BMS, estates managers now need to understand these systems and the IT perspective.
Look at how your BMS is set up; it may be possible to reduce costs using your existing systems by refining the programming.
A BMS is only as good as the data it provides and the control it allows – your existing setup may not be configured in the best way.
Identify what systems you currently have and what they do.
- What kind of building management systems do you have?
- What do they measure and control?
- Are there other systems, such as those controlling timetabling, that you would like them to be connected with?
- To do what?
Think about the level of integration you want (or can afford). What do you want to achieve? It is extremely important to specify exactly what you mean by ‘integration’ – what systems are to be included and what do they need to do? Vague specifications can lead to inflated costs as providers may not understand what you need.
It is worth working out early on how much it is likely to cost to achieve your vision, and setting a budget. If you can provide projected figures on what your integrated systems could save in terms of energy use for heat and light, this will help your case when applying for funds.
Any integrated system you plan needs the flexibility to respond appropriately to different scenarios. If the building changes use, this allows you to make appropriate changes easily. If you don't have a flexible architecture you're going to struggle to drive down energy costs in the face of change.
Use our impact calculator to demonstrate the impact of a process redesign or system implementation by quantifying the tangible benefits or efficiency gains that can be derived from it.
The importance of data collection
Energy use data are important for:
- Working out how much you are spending and where
- Planning building use
- Identifying problem areas
- Projecting likely spend
- Working out how much you could save by making changes
Improving on planned building performance
2013 Green Gowns award winners (Technical Innovation category) University College London are leading on a free online tool called Carbon Buzz to help organisations to better understand the gap between the planned and actual performance of buildings. Carbon Buzz provides a platform for directly assessing the live building performance against design expectations.
Supported by CIBSE and RIBA, Carbon Buzz represents a collaboration between academics, architects and building engineers. Funding has been provided by the Technology Strategy Board, among others.
Academic, technical and estates teams need to work together to get the best results out of a new and or integrated system.
Software developers, estates managers and commercial providers can all offer useful insights when planning systems to run buildings more efficiently. Communication between estates staff and IT practitioners is vital, so technical expertise on areas such as interfaces and standards, and the current set-up of any BMS, can be shared. You may also need advice from an external provider or consultant on improvements or changes.
For systems that are going to work intelligently alongside the timetabling of classes within buildings, academic and administrative staff will need to be involved to ensure that teaching is not affected and that any alteration to timetabling systems as part of integration is understood by those using it.
Systems that are going to be integrated are often held within different domains within the institution, with different aspects managed by different people, which can mean it is uncertain who should have overall responsibility for the new system. Make sure everyone involved is aware and a decision is made.
Integrated systems will naturally bring complexity. Training for users and documentation of new systems and how they are connected is critical, so people know how to use them properly and are aware of what data and functionality the systems can provide.
Case study: Strathclyde U-CARE project
The University of Strathclyde’s U-CARE project developed a software application, ECO-APT (Energy Consumption and Occupancy – Analysis and Planning Tool), to enable the graphical display of occupancy data alongside energy consumption data for their computer lab.
ECO-APT was developed specifically to trend energy consumption data against occupancy data and to establish a correlation between the two, enabling future need for heating/cooling, based directly on occupancy, to be modelled. In this way, usage information can potentially inform building optimisation strategy and timetabling activity.
The potential savings using this model have yet to be confirmed and could not be completed within the scope of the U-CARE project, but the potential of applications like this can be clearly seen.
Webinar: efficient buildings
This is one in a series of guides around green ICT. You may find also the following of interest:
- Engaging users to reduce energy use
- Reducing your ICT energy costs
- Using videoconferencing and collaboration technology to reduce travel and carbon emissions
- Improving energy efficiency in your data centre
- 1 Source: University of Aberdeen website http://www.abdn.ac.uk/environment/energy/lighting