Calling the rise of wireless technology a trend is kind of like referring to a hurricane as “a windy day.” We’re all for embracing new ways to keep our clients comfortable in their environment, but is a wireless solution always the best option? Pete Cattie, a Project Manager for Oliver Mechanical Services, doesn’t think so. Here’s his take on why we shouldn’t be so quick to default to wireless solutions:
WIRELESS, WIRELESS, WIRELESS. Everyone is jumping into this new technology thinking that this is the way to go. Is it? In the commercial side of the HVAC business I see it as the last resort if all other standard and reliable means are exhausted. About 10 or 15 years ago Honeywell came out with a wireless product and I thought it was the neatest thing. No one bought it so they dropped the product, and now it has returned. Don’t get me wrong: there are places that a wireless solution is a perfect fit and I will try to explain.
With wireless systems, the signal strength is important in transmitting information to the piece that you are operating. Most of the wireless companies are currently working in the 2.4 GHz and 900 MHz range, with other bands in the wings. These two bands I mentioned are pretty robust, with pretty solid signal strength. The potential problem is that these bands could potentially interfere with other critical equipment that you are operating, and it could start to work erratically. I highly recommend doing a test in the building to see if it will work before purchasing.
ZigBee is one of the bigger wireless companies operating in commercial HVAC. With their system, and most of the others, it’s important to keep in mind the distance that you can transmit a signal. Line of sight gives you the longest range, but if you have to transmit through walls and other obstacles it will reduce the signal strength and total distance you can allow between equipment. A mesh network is a nice feature that most companies – in other words, if you lose one piece that was part of your network the signal will find another path utilizing other wireless pieces on the network.
Another consideration with wireless is cost. It’s important to compare the total costs of both traditional and wireless systems before making a final decision about the best solution for your site.
How do these considerations play out in the real world?
I was called out to a shopping mall in Delaware to look at putting controls in to replace their pneumatic system. The mechanical rooms were spread out all over the mall, and we can all picture how large of a space that is. The problem was: how to connect each of these 5 mechanical rooms, with all of their controls, to the main controller. My recommendation was a system from wireless company AIC-Wireless that has the capability to transmit up to 7 miles, and is very versatile in the communication protocols it’s able to transmit. I designed a solution that set transmitters in the outside air ducts, on the roof, and pointed the antenna towards the next mechanical room. I did this in all five locations, and connected all the mechanical rooms to the main controller without having to spend the time and money to run the wires throughout the mall to each mechanical room. In this situation, wireless technology was a more cost-effective way to meet our client’s needs across the large space of the mall.
In another example, our client was a suburban college in Pennsylvania that wanted to sub meter buildings on their campus. When we started the project, the customer stated that he wanted to do this wirelessly. However, when we began researching we found that the scope of the project exceeded the manufacturer’s recommendations for a wireless transmission system. When we reached this conclusion, I asked whether the college had an existing LAN network, which it did. I was able to recommend a solution from meter company E-Mon which offers a product that could be installed on their existing LAN network, record the electrical information, and transmit it back to his building automation system or to E-Mon software without running wires. In the course of our discussions about this project, the client mentioned that he had an employee assigned to drive around to all 15 buildings, once a month, and record gas and water readings. It just so happened that the meter I was recommending for the electrical sub-metering was also able to record these two readings and send it back to the building automation system. This resulted in a triple win for our client: we were able to accommodate his original request to not run new wires without creating future headaches by installing a wireless system that wasn’t a great match for his needs, and he freed up an employee for other duties.
Of course, this article is only a very brief overview on wireless systems. What I am trying to convey is that there is a great deal of information to consider before making your decision about a wireless solution. Your best bet is to discuss the goals you want to achieve with a trusted, qualified contractor who will guide you down the path towards the best solution, utilizing the right technology. I would be honored if Oliver is your contractor of choice, and happy to help you design a solution for your facility.
Considering a wireless controls system for your facility? Or just have more questions about what this technology can do for you? Give us a call today, our experts will be happy to help you.