Pros and Cons of Wireless Building Automation Systems

By Gislene D. Weig  
OTHER PARTS OF THIS ARTICLEPt. 1: This PagePt. 2: WiFi, Zigbee, EnOcean Are Most Common Wireless TechnologiesPt. 3: Construction Materials Can Interfere With Wireless BAS Signals

While wired building automation systems (BAS) are both successful and easily implemented when planned in advance and installed during new construction, they are not always a viable solution when dealing with existing or historical buildings, where adding cables can be challenging, costly or aesthetically unappealing. In instances such as this, wireless systems or hybrid systems (a combination of wired and wireless) are often the ideal solution, there are pros and cons of wireless building automation systems to be considered.

In a BAS network there are mainly three tiers. Tier 1 (top level — primary bus) is where devices such as logic controllers, workstation terminals, Web servers, and other supervisory devices are networked. Tier 2 (the secondary bus) connects to major mechanical, electrical, and plumbing components like the central plant controller, air volume box controller (VAV), boiler controller, and lighting controller. The third tier is where end devices like thermostats, lighting sensors and other sensors are located. The most common implementation for wireless BAS has been at the sensor level (tier 3) due to the ease of installation, flexibility, and lower installed cost.

From an IT perspective, there are six key components for wireless: available technology types, reliability, wireless link, interference, security, and battery life.

5 Reasons To Think About Wireless Lighting Controls:

  1. Opportunity: Lighting accounts for 25 to 35 percent of energy use in a commercial building.
  2. Options: Wireless may be a cost effective way to add scheduling, daylight dimming, occupancy sensing, personal control and demand response capabilities, according to E-Source.
  3. Savings: A wireless system with full dimming — including daylight dimming, high-end trim dimming, lumen maintenance dimming, and occupancy sensing using both wired and wireless occupancy sensors, wireless photocells, and wireless area controller, with dimming ballasts — has the potential to reduce energy use 49 percent compared to ASHRAE 90.1, according to a study by Clanton and Associates.
  4. Commissioning: It's a necessity, regardless of whether lighting controls are wired or wireless, say experts.
  5. Rebates: Some utilities offer incentives for lighting upgrades. Check www.dsireusa.org.

— Edward Sullivan, editor


When to Consider Wireless

There are many reasons to consider wireless building automation systems (BAS).

  • When there is a desire or requirement to implement BAS networks in new, existing or retrofit buildings where wiring is a challenge.
  • If adding more sensors and actuators throughout a building can further improve the comfort of occupants while reducing energy consumption.
  • When wiring is either aesthetically undesirable or cost prohibitive (e.g., historical buildings).
  • When there is a need to increase flexibility. Without a need to re-wire, tasks like re-locating or adding thermostats and sensors throughout a space become extremely easy, with a minimum of disruption to tenants.

— Gislene D. Weig

Continue Reading: Controls: 6 Keys to Wireless Systems

Pros and Cons of Wireless Building Automation Systems

WiFi, Zigbee, EnOcean Are Most Common Wireless Technologies

Construction Materials Can Interfere With Wireless BAS Signals

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  posted on 3/10/2013   Article Use Policy

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