Facilities and buildings account for approximately 40 percent of energy consumption across the globe and are responsible for 30 percent of the total emissions of carbon dioxide. These issues have warranted a drive towards metering and sensor installation approaches, such as submetering and CTs, but which approach is best to use?
To execute green building practices, facility managers, building engineers and their teams must be privy to methods for sustainability. Understanding the factors that affect energy consumption in a facility requires knowing how and when energy is utilized. Submetering and CT monitoring both offer viable approaches for monitoring energy consumption and the status of equipment. But knowing which one is right for a facility requires understanding how submetering works versus how CT monitoring works for effective visibility of equipment status and energy consumption. The differences between submetering and CT monitoring and their best applications are outlined below.
Submetering works by installing energy-measuring metering devices. When using submetering to monitor energy consumption, property or facility managers can measure individual units, including the power consumption of equipment and specific departments. For example, it can be used to keep track of the actual power consumption of a tenant's suite in a commercial facility or apartment building. It's important to recognize the advantages and disadvantages of submetering, including:
- Useful for measuring energy consumption in multiple units, such as monitoring tenant energy consumption of an apartment building
- Real-time monitoring and actual power consumption monitoring for accurate results
- Useful for tracking energy consumption patterns to help improve building efficiency
Current transformers or (CT) measures alternating current (AC) power. These sensors are best for measuring the generation or consumption of an entire building. The sensors work similar to nerve endings of the human body. They send information back to the controller. This form of power consumption monitoring is ideal for gathering estimates of energy consumption. For example, CT monitoring is useful for providing the virtual channel estimation to prevent energy leakage to maintain compliance with local and state regulations regarding energy control measures. Property managers can also garner data from CT monitoring sensors for the estimated power consumption of a facility. However, there are advantages and disadvantages of CT monitoring the are vital to note when making a decision on which is best for achieving facility management power conservation goals.
- Split core CT sensors don't require high-voltage electrical wiring
- Useful for tracking energy of entire buildings
- Can be dangerous to install if open-circuited
- Not best for providing actual power consumption measurements of individual units
Which to Use?
Deciding on whether to use submetering versus CT monitoring will depend on the facility management goals of the enterprise. When looking for the actual power consumption of a facility, submetering offers a better solution. However, if facility management goals only require estimates, then leveraging CT monitoring can prove advantageous. CT monitoring also can be a better fit if the goal is to monitor the entire building's consumption while submetering is useful for measuring the energy consumption of individual units in a multi-unit facility.
Knowing the difference between submetering and CT monitoring is essential for implementing sustainable building practices. To leverage smart building practices, it's also important to employ greentech building technology that takes into account both building control approaches. Submetering can be effective for monitoring energy consumption on an individual basis, and CT monitoring can be useful for monitoring estimates of energy consumption of entire facilities. Before committing to one specific approach, facility managers should consider the best power consumption method that fits the business' facility management goals.