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Access Control Systems Improve Energy Usage

12 March 2019

Building Energy Usage

BACnet is a communications protocol developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) to provide a common communications protocol for building services and related systems. BACnet is an abbreviation for ‘Building Automation and Control network’ and is today used by many building critical systems as a way to provide operational information and control to central monitoring points such as a Building Management System (BMS). Typical systems using BACnet include HVAC heating, ventilation and air conditioning systems, lighting controls, life safety products and some access control systems including the Entro Series from Remsdaq.

Native BACnet and Subscriber Objects

The Entro series of access control panels, readers and management software, was the first access control system to include native BACnet. Any device described as having ‘native BACnet’ means that the device manufacturer has implemented the ASHRAE protocol, guaranteeing that their product will communicate with other BACnet enabled devices from other manufacturers. Where a device does not include native BACnet, the manufacturer or supplier may offer a BACnet server to translate the product protocol into BACnet.

The BACnet protocol defines device/controller components as ‘objects. It is up to the individual product manufacturer to determine which ‘objects’ are visible to other BACnet enabled devices and those (objects) to which these devices can subscribe in terms of: read only, read/write and none/not visible.

For the Entro series, BACnet allows for Peer-to-Peer communications between the Entro door access controllers (EntroStar and EntroNet) and other devices and eliminates the need for integration through a security front end. As a manufacturer, Remsdaq has published a Protocol Implementation Conformance Statement (PICS) document listing the built-in Entro series BACnet objects and defining what the user can do with each of these. When a BACnet enabled device subscribes to an object, changes in the object status can generate a notification to all subscribers. Using this information, subscribers can detect event notifications which can include door opening, closing or an alarm condition when the door is left ajar or forced.

BACnet has become more important within recent years through the adoption of smart building systems. The aim of these is to provide the best possible work environment for the building users and achieve the highest possible energy efficiency. Many new building specifications now includes a section on ‘wellness’ or ‘wellbeing’ describing what is required from the building fit-out to create as productive and energy efficient environment as possible.

Building Management and Energy Efficiency

Almost everyone who works within a building is aware of climate change problems and the need to be more energy efficient. According to the US-based International Energy Agency (IEA), the building sector accounts for:

  • 25% of energy related CO² emissions
  • 30% of total final energy usage globally
  • More than 50% of global electricity consumption

These ratios are high and any reduction can have a large impact on energy consumption and electricity bills.

All buildings have a core infrastructure that includes some form of temperature control and lighting. Temperature control systems can include traditional heating (oil-based, gas or electric), air conditioners and outdoor heat pumps. Lighting can range from older tungsten lamps, typically fitted in warehouses to the latest energy saving LED lighting. Overall the IEA estimates that temperature control and lighting can account for over 57% of a building’s total energy consumption, with up to a third being wasted through poor optimisation and reduced energy efficiency.

Most buildings have areas of high and low usage. The challenge for many building operators, engineers and facilities managers is how to optimise temperature and lighting controls throughout a building, ensuring a comfortable environment when needed. Conditions and usage trends change based on many factors including economic, seasonal, time of day and weather related.

One of the biggest hurdles to managing core infrastructure systems within a building is that of knowing how populated a building is and where the occupants are on a minute-by-minute basis. The primary system that can help provide this information is a BACnet enabled access control system such as the Entro series.

Data Capture and Analysis

Access control systems consist of door controllers, card readers (or keypads or biometric readers) and a management software package. The software database contains credential information which is used to verify whether a card holder is authorised to pass through a controlled doorway. The card holder presents their credential (normally a MIFARE card or key fob) to a reader. The information is checked by the access control software and if the person has authority to enter, the door controller is instructed to open the door. Biometric credentials work in the same manner as do electronic keypads, mobile phone credentials and other types of proximity card readers.

An access control system like the Entro series can provide two sources of building population information:

  • Overall at the systems level, the credentials database can provide information on who is in a building and the last controlled door they went through.
  • At a component level, a BACnet enabled door controller like EntroStar or EntroNet can provide information via ‘Object’ subscription, and again indicating the last door a credential was used at.

Not every space within a building may use a door controller for access. In these areas, Internet of Things (IoT) beacons can be used to track people movement using wireless technology. These beacons rely on Bluetooth and can be incorporated into the holders used for a Mifare type card. The beacons tracks movement through wireless hubs which typically have to be placed every 8m or so.

Collecting and analysing building occupancy and movement data can help to greatly improve energy efficiency and improve building productivity and the overall environment for its users. Unoccupied spaces require less or even no lighting or heating if they are not in use. Washrooms and stores areas may be used sporadically or within peak demand times. Knowing the traffic levels within specific parts of a building, allows building managers to reset thermostat and system set-points, as well as optimise maintenance schedules and related upkeep programs. Manual system overrides can also be monitored, as way to track whether pre-set temperature control settings are reasonable for the time of year, time of day and population usage.

The more complex the building and systems, the more difficult the analysis problem is itself. Middleware software platforms provide an integration route for the various access control, population and movement data sources available. Within these software packages, data can be analysed and compared to trends against rule-based algorithms. Changes in energy usage can automatically trigger alarms, promoting investigation and further analysis. Often these can be tracked back to sudden changes in population usage, system maintenance, seasonal variations and other unexpected events. The tracked data can also be used for building performance forecasting and ‘what-if’ scenarios with regard to increased usage as more space is made available or for when it is overpopulated. Another example includes using credential-based data to set-up ‘hot-desk’ areas based on personal preferences and past configurations.

Summary

Today, smart access control systems can provide additional benefits to organisations that install them. Building, contents and occupant protection from external threats is guaranteed but with the added benefit of the generation of information that can assist smart buildings to make the right decisions. Decisions that are more intelligence-based than those available from simple motion detecting light switches and thermostatically controlled heating or air conditioning. Furthermore, there is a case to be made (depending on the size of the installation, energy usage and efficiency) that installation of BACnet enabled access control systems like the Entro series, can lead to a payback within a one-to-two-year time frame.

For more information on ASHRAE and BACnet please see: https://www.ashrae.org/technical-resources/bookstore/bacnet or contact Remsdaq. For more information on the integrated security solutions available from Remsdaq or to discuss the Entro series BACnet PICS document please contact us.