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Tech made easy: let’s talk about building energy management systems (BEMS)

What we’re talking about: Building energy management systems (BEMS for short).

Why? To optimise your building energy performance and reduce energy use.

What is it? It’s a smart computer system that looks at all the energy demands and use patterns in your building and figures out smarter ways to do things. It could be part of a wider building management system that handles all the automated aspects of a building, such as energy, security and fire systems. Or it may simply handle the energy side of things – heating, ventilation and air conditioning (HVAC) as well as lighting and power.

Who would use them? They’re typically designed for large buildings, factories or warehouses. Also organisations that have multiple buildings spread around an area, such as health trusts or local authorities. However, you can get mini-BEMs for single or smaller buildings.

How do they work? There’s a central computer that’s connected to all your building’s energy components. This sends and receives information in order to optimise energy use. So, for example, it can get information from boiler flow and return temperature sensors, internal and external temperature sensors, occupancy sensors, humidity sensors, light sensors….

You’re saying the word sensor an awful lot. That’s because sensors are integral for all the data that needs to be collected. Have you heard of the internet of things? It’s the network of physical devices, vehicles, appliances and suchlike which are all embedded with electronicssoftware and sensors that allow this flow of information. It means things are going to get a lot more efficient. It’s the future.

It feels like the future is here already. Indeed. We are now living yesterday’s tomorrow.

And what happens with all the information that is being sensed? It’s sent via energy routers to the central computer where it can be stored for later analysis or used for real-time monitoring of buildings and energy appliances. For example, the system can be set up so it sends alarms when parameters or thresholds are breached. This could be an indicator that something’s gone wrong or a piece of equipment is in need of maintenance. Then you can input information to the central computer, which will change the settings on any of your building energy components.

Which presumably I can control from anywhere? Correct. If it’s internet-based you can access and control information from computers, tablets, smart phones – all the usual devices.

And how would I optimise all the information? They’re great for building up an historic picture of energy use in your building or buildings. They can generate reports and visualise the data to help you see what’s happening and determine patterns. So you can see, for example, how your building is performing when compared to similar buildings, or across different time periods.

So I can see if I’m saving energy compared to when I installed this a year ago? Exactly.

How much would a system like this cost? Hmmm, this is like the ‘how long is a piece of string’ question. There are so many variables. There’s the cost of the system itself, the installation cost, and any maintenance costs. It depends on how big your building is, what you’re monitoring and whether or not you’re adding it on to an existing building management system. This can be done with a few tweaks here and there.

But we’ll save lots of money? It’s hard to pin down a number because it depends on how efficient your building is already, but you should make savings on your bills of around 10-20 per cent.

Are these systems off-the-shelf or custom built? They can be either, depending on the complexity of your needs.

How onerous is the maintenance? To optimise internal conditions, and make ongoing savings, energy management systems need to be maintained regularly. The settings need to be reviewed at least every month so you can see if the settings match actual building use. You’ll also need to check physical things like the cabling, connections and sensors, checking if the sensors are accurate and check they’re in the best location. You should also record any changes or additions made to the system to keep it manageable and keep track of what’s where.

That doesn’t sound too bad. I’m convinced and ready to go… Great! Just bear in mind that for an energy management system to work effectively in an existing building, you need to be able to zone the heating, ventilation and lighting systems so you can alter settings according to use. Also, before you install the system, you’ll need to decide if you want it installed by the manufacturer with their maintenance package, or have it installed independently so you can shift the maintenance contract.

Sounds good to me. And if you want to find out more, don’t forget to give us a call on 0808 808 2268 or email us.

Our support to reduce your business costs are funded by the Scottish Government and by the European Regional Development Fund through the £73 million Resource Efficiency Circular Economy Accelerator Programme.