11 Oct 21
I have worked in the BMS Industry for two of the major manufactures, Trend (now Honeywell) and Satchwell (now Schneider) the technology is probably one of the most complex technology within a building, but if it is not over complicated it could be one of the best ways of managing your energy. Because it provides visibility and it provides control. I would also go as far to say that 100% of all new commercial buildings today will have a BMS and possibly 90% of all the commercial buildings we visit today will have some form of BMS control.
The BMS system is made up from inputs and outputs with intelligence in between. Therefore, simply a room sensor would be your input and the output would be the heating and based on the temperature in the room the heating would be on or off.
Now this is oversimplifying the BMS. Because there are other parameters, we can start to bring into the equation. For instance, time of people in the building, outside temperature, the day, required temperature setpoint and even the optimal time for the room to be at temperature.
Now we are starting to complicate the technology and the intelligence required to drive the output because now we need more inputs. The inputs are made up of the following:
· Inputs
o Analogue – temperature, humidity, pressure, and air quality
o Digital – on – off signals, indicators, and counters
· Outputs
o Analogue – Valve positioning, damper position, and speed control
o Digital – on / off Enables
A BMS can save in the region of 35% Energy now that is a bold statement and I have been involved in various studies in the mid-90s where we proved these savings. These saving are all concept savings from design and will only be achievable if the BMS is being maintained by a specialist. Far too often a BMS is installed and there is no training provided and no support. This is critical, I have been to buildings and maintenance teams have not even had the password to the system and have never been trained on the system. (I normally have a library of datasheets to hand to share with them). Especially the older systems of Trend and the NDPs of this world.
Above is a Trend NDP Network Display Panel
Whenever I am on an assessment and I see one of these (I smile) and then I predict the following:
· Maintenance team do not have a ‘Password’
· They do not know how it works
· There are no times set-up
· There are no training notes
I always carry these with me on my IPAD, I would seek access to the system and provide training there and then (I always say here, I have probably created 5% savings alone on the day). Before we started, the maintenance manager did not have access to the system, there was no visibility and there was no control. What we find in addition that all the plant is in ‘manual’ (Please prefer to a previous article about Hand-Off-Auto.
The BMS by rule of thumb will control the following ratios of energy:
· 55% of Electricity will be connected to the BMS (more if there is lighting control)
· 100% of the Gas if there is no catering or 88% of the gas if there is catering
So, you can now start to see that the BMS is a critical system within the building to be ‘Managed’. If you are an organisation with a BMS or you are planning to install a BMS you must consider the ‘Life Cycle’ of the product. Because these systems are normally backward compatible it is likely to be able to add to the system in the future. Remember during the ‘Life Cycle’ buildings change and control strategies need to keep in line with these changes. It is also that you are likely to see old systems on the same network as new systems.
If you are installing a BMS or you have a BMS (in fact any energy management and energy saving systems in place) these are the principles to follow:
1. Always provide training to the staff who need to operate and maintain the system.
2. Keep staff fully informed with any upgrades or changes to the system
3. Maintain a monthly or quarterly review to the system’s operation.
4. Keep all documentation up to date to the system drawings and changes.
5. Have the system supported by a specialist minimally twice a year or monthly (according to system criticality) and keep a log.
6. Carry out an annual review to align the building, the organisation, and the system
To conclude we have reviewed the importance of the BMS what it can do and what it can achieve and how it should be wrapped in cotton wall to protect the return on investment of the property owner and management.