Babel Buster: It is how to connect things to BACnet.
The Truth Behind Building Automation
Deciphering Fact from Fiction
Western Allied Mechanical
all been told to spend more money on building automation, but is
everything you’ve heard actually true? Is this new revolutionary
automation system you’ve installed really going to save you money?
Should you upgrade your current system to make it faster? How long can
you actually expect your DDC system to last for? The answer to these
questions and a few more can be found in this article about how to
better navigate fact from fiction in the world of automation.
So what do you know about your automation system? Have you heard the term BACnet but wondered what it meant? What can the DDC in your building do for you? So just how complicated is your system? Building automation is often undermined in technological advancement although it continues to play a heavy role in energy usage and management. Here are a few questions and answers about what you can expect with your next controls upgrade:
Question: What is BACnet and is it truly “open”?
Answer: BACnet is simply a communication protocol between automation field devices. Meaning, when your air handler talks to your zone VAV units or chiller plant, it does it with the BACnet “language.” Communications are established through a twisted -shielded pair of wires that runs around a building and ties together all the equipment controllers. BACnet, Lonworks, and Modbus are all examples of languages between controllers communicated over a pair of wires running throughout a building.
Automation manufacturers have tried to establish a standard of
communications between devices to create an “open” architecture. The
idea is to develop the standard for every manufacturer, allowing the
customer to choose several different vendors within their building.
Google tried the same idea in their Android mobile operating system
development which has essentially shut down as of October 2013. Why?
Every manufacturer took the Google backbone, twisted the idea with
their own programmers, and locked it down (Verizon, Samsung, and Kindle
for examples). Every openly developed software can be proprietized by a
manufacturer which includes communication protocols like BACnet.
Question: Can my building automation system help cut down my utility bill?
Answer: Building automation is a control method for the mechanical systems
within your building. You may not have new equipment or VFDs (Variable
Frequency Drives) on every motor, but there are likely still savings
that you could drive with a new automation system.
Take for example a small office building with constant volume package units. What could you possibly get for energy savings in this environment? Fan energy, or the energy used to blow air out of the grill in your office, comprises almost 70% of the energy consumption in a building. By controlling the fans more tightly with a schedule you can save up to 15% on your bill every year. To take it one step further, by increasing cooling and decreasing heating setpoints during peak usage hours you can alleviate 5-10% consumption; all with minimal impact to your workforce. That’s up to 20-25% reduction without any mechanical upgrades.
Question: What if I’m tired of my current controls vendor? How hard is it to switch vendors?
Answer: Although any vendor exchange within a site will come at an expense, you can minimize it with the right strategy. Historically, building automation systems have been proprietary to single or sometimes multiple vendors in a given territory. If you didn’t like your vendor, you’d have to strip out all the equipment at your site and start over (an expense typically in the six-figure range for most facilities.)
control systems like Tridium can integrate your old equipment and
prevent proprietizing your site to a single contractor. Integrations
like this not only open the market to competitive bidding, but can cut
integration costs as much as 40-50% versus the traditional
Remember, switching vendors in most cases
doesn’t simply mean bringing in any contractor and having them work on your current system. Controls
vendors may be able to work on a few different systems, but accessing
the software necessary to program your facilities’ system may be impossible due to its proprietary nature.
Question: My controls vendor said I need to upgrade my system to make it faster. Is that necessary?
Answer: The unfortunate part about technological advancements in everyday use, through handhelds and cellphones, is they’ve taught us
that speed is everything. Faster computers mean increased productivity. Faster Internet means quicker loading times while surfing. But is speed a necessity of building automation? After all, it is part of the technology boom.
Speed in automation is only critical when considering industrial applications. Industrial PLC (Programmable Logic Controllers) need to compute information twice as fast to make sure control of variables like temperature and pressure fall within industry standards. These controllers are extremely costly in comparison to a commercial application that is only concerned with occupant comfort.
If you’ve ever watched a temperature increase in an occupied space you could easily compare it to grass growing. Unless a space is overwhelmed with occupants, the fluctuation of temperature is extremely gradual; thereby decreasing the necessity of faster control capability. Basically, speed is not conducive to a properly controlled commercial application and is not a valid reason to spend tens of thousands of dollars for an upgrade.
Question: How long can I expect my control system to last?
Answer: Control systems have historically lasted for 10-15 years on average when considering mid to late 90’s installations. Unfortunately, with the pace of technology, your physical controls equipment is likely to outlast the associated software support for the installed product line. Now you are dependent upon the manufacturer to support the product line for up to fifteen years which is highly unlikely.
Take for example the cases of Apple and Microsoft. Windows XP was released in 2001 and remained the staple of Windows operating systems for around 11 years. Many companies are being forced to upgrade now to the new Windows 8 plaftform with the lack of support from Microsoft. The new Windows doesn’t support older hardware and, therefore, companies all over the world are having to upgrade their machines to match the new software.
When considering Apple, think back to the days of the iPhone 3G and
when it was released in 2008. By 2011, the last version of Apple
Updates was released for the 3G iPhone essentially guaranteeing its
hardware obsolescence by 2012 - only 4 years later.
No technology, including building automation, can ever expect to embody the longevity assumed in the 90’s. With the quickened pace of high-tech advancement all owners can hope for is hardware manufacturers that can manage revisioning for at least 5-7 years.
Question: My vendor said they needed to replace all the wiring in my building because it was old. Do new systems need new wire?
Answer: Wire install costs within a facility, especially one that’s occupied, embody at least 25-30%
of the total project costs. Rewiring occupied spaces comes at a heavy
expense in either occupancy comfort or total project cost. If you
decide to rewire your building after hours to alleviate tenant
dissatisfaction, the overall cost can be expected to increase as much
Most controls contractors can utilize either the BACnet or LON protocol to recycle your existing wiring and cut down on expense. In order to reuse existing controls wiring, contractors need to have in-depth knowledge on how to tune or reduce traffic on the system to ensure proper operation.
About the Author
I currently maintain an engineering sales position at Western Allied Mechanical. Our business is consulting customers on energy consumption and reducing costs through a joint mechanical and automation venture. I’m an avid follower of the industry and am always open to new opportunities and approaches. You can reach me at email@example.com or my cell at 650-798-4154.
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