Actualites - How do you choose a BMS that suits your needs?

How do you choose a BMS that suits your needs?

Expert article

We asked Frédéric Wafflart, Business Development Director at AREAL, three questions to shed light on the criteria for choosing a BMS system.

Question 1: As part a BMS project, what advice would you give during the requirement definition phase? 

In my opinion, a distinction needs to be made between an existing building and a new building. 
For an existing building, I'd highlight two essential steps to follow.

  • Firstly, take stock of the installations already in place and know the current energy consumption (by functional area and by energy type plus, if possible, an idea of the intensity of use). This will make it possible to assess the installations' performance relative to the standard and estimate the savings to make and also the financial effort to devote to installing the BMS.     
  • Secondly, conduct an inventory of the installations to list the equipment in place and its communication capability. These elements will make it possible to define specifications adapted to the existing situation, the energy consumption reduction goals and the budget, and therefore to assess the ROI of the investment.

For a new building, defining the requirement is simple. You need to go for the ultimate in BMS to comply with the regulations. I therefore advise investing in a highest level BMS. This solution incorporates supervision software paired with an energy monitoring tool. Although this tool is native to supervision, it's a must: it guarantees the cohesion of the solution and reduces the implementation costs that need to be taken into account from the start of the project.

In addition, all of the BMS components need to be open and interoperable, e.g. through the use of standardised and open communication protocols such as BACnet IP, Knx, Modbus TCP IP, etc. The idea is to choose a lasting and scalable solution that facilitates the integration of new technologies over time to serve the energy efficiency goal of your building(s). 
 


Question 2: In your opinion, what are the qualities that a "good" BMS needs? 

Firstly, I think it's essential to view the BMS as a way to reduce overall operating costs. The aim is to achieve a return on investment as quickly as possible. According to the CEREMA*, heating savings of around 38% can be achieved with a level 3 BMS that incorporates supervision software and an energy monitoring tool, versus a BMS that simply performs a monitoring function. This is the observed feedback.


With this in mind, here are the criteria I believe are essential in choosing the right components for your BMS:

  • Interoperability: don't hesitate, for example, to impose open inter-component communication protocols, such as BACnet IP, Modbus TCP IP and Webservices, and avoid the proprietary protocols of certain manufacturers.
  • The integration into the BMS of scalable supervision software, independent of manufacturers and natively incorporating a proprietary/operator-oriented data processing tool. This is the prerequisite for having an intelligent control tool that is essential not only for planning and optimising work operations, but also for targeting the improvements to make to the building's installations.
  • Lastly, the BMS system chosen must allow you to verify that the installations' energy performance always matches what the manufacturer promised (especially in the case of new buildings).


Question 3: What expert advice could you share with those embarking on a BMS project?  

Whether it's for a new or existing building, my main advice is to view the BMS as a continuous improvement tool that will evolve to optimise operating costs on an ongoing basis.     
The statistical insight offered by supervision software integrated into the BMS allows you to orchestrate upgrades linked to the energy performance goals. This way, you can test your improvement ideas before rolling them out on a larger scale.
In general, the BMS needs to incorporate intensity of use by area (presence, number of people, etc.). This is essential for measuring and optimising energy efficiency.
To give you an idea, experts estimate that fine-tuned management of the intermittency of presence can reduce energy consumption by 15%.     
Lastly, and in order to clearly state your energy sobriety ambition, I recommend setting up an energy performance contract with the operator and an energy sobriety charter through which the building's stakeholders will commit to reducing their energy impact.
 

*French public establishment under the supervision of the Ministry of Ecological Transition and Territorial Cohesion
 



Going further… 


A few tips once the BMS has been installed:  

On a day-to-day basis for managers, avoid micro-management. Focus on contextualised dashboards with key indicators that will identify energy efficiency shortcomings. Ask the operator to publish its dashboards on equipment performance compared to benchmarks.

For operators, I recommend weekly dashboards to spot optimisation faults and identify equipment that needs to be adjusted, maintained or replaced. 

Lastly, energy efficiency in buildings is everyone's business. 1°C less in the open space can make a real difference! Sharing information with users about their impact on consumption is key to achieving goals.