Building Controls

Building Controls Questions

  1. What suggestions are there for building monitoring systems? What criteria should we use to select them?
  2. Are there good estimates for energy and costs savings generated by using EMS or BMS systems?
  3. What devices are recommended to track energy use at the individual appliance level?

Building Controls Answers

1. Q: What suggestions are there for building monitoring systems? What criteria should we use to select them?

A: According to a 2009 Climate Corps fellow, the criteria he and his company used for selecting an EMS vendor included that the system be real time, web-based (IP protocol), scalable on an enterprise level, fit on top of existing systems and read most commonly used BMS protocols (Bacnet, Modbus, LonWorks, etc.), and have graphically rich user interface with a variety of tools variously appropriate for engineers, executive decision makers, and end users. We were also, initially, looking for someone who could do branch circuit monitoring.

He looked at a few vendors, including Northwrite, Archrock, Integrated Building Solutions (IBS), Triacta, Gridlogix (acquired by Johnson Controls), and Agilewaves. He ended up choosing IBS for the whole building monitoring system, commenting that the interface is terrific, they customize solutions, and they seemed like really smart guys.

He added, most companies will be glad to set up a WebEx session to run you through the functionality of their products. I found this helpful, actually seeing how they worked and what they looked like.

2. Q: Are there good estimates for energy and costs savings generated by using EMS or BMS systems?

A: Payoffs and causality are often really hard to justify in advance when implementing EMS systems. It's hard to know what inefficiencies you will discover until you discover them, and the amount of savings will depend on the actions and skills of those who receive the data. My building engineer just implemented a significant HVAC reduction last month, without the EMS, but might have done so more quickly or efficiently with the EMS. Very hard to say, but I am a firm believer in the power of real time knowledge.

Download a study by TIAXX commissioned by the DOE which analyzed projected savings from EMS or BMS systems. It's quite long, but the executive summary will give you a nice overview. The main points are that between 4 and 20% of all consumed energy in commercial buildings is wasted. This comes from 3 main sources: improper ducts, HVAC left on when no one is in the room, and lighting left on when no one is in the room. They also found that while up to 20% of consumed energy is wasted, integrated diagnostics and controls looking at the entire system can actually save more than just the wasted energy. Savings accounted to anywhere from 14-38% from the baseline.

3. Q: What devices are recommended to track energy use at the individual appliance level?

A: Here is a list of devices that can track energy use at the appliance level:

  • Kill-A-Watt: EDF used the Kill-A-Watt and found that it works great to measure energy usage from laptops, desktops, monitors, chargers, and some other random appliances like a toaster oven or treadmill. It gives energy usage at any given time as well as cumulative totals and is relatively inexpensive.
  • Watts Up Meter: The Watts up meters seem to gather and store time series data much like the HOBO. Applications where this could be interesting, are connecting to servers or other big equipment and finding out how the power consumption varies over time. The web-enabled version could certainly be useful and if $200 bucks isn't a big deal, it would certainly be a fun toy to play with but you can do the job with the basic non-web one.
  • Power Meter Store: Sells a variety of these types of devices.

Things you might want to think about in choosing which model are whether you need only spot readings on a bunch of loads, or want memory so the meter can stay in one spot and track usage over time. Also, some fancier meters will have the ability to take stored data and upload it to a computer.

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