Energy metering devices (also known as data logging meters) are improving rapidly. Data logging meters, such as power and light intensity loggers, are important tools for diagnosing building system issues and/or calculating how much energy certain equipment is using. They also allow you to see how individual equipment is performing over time, which is key for measurement and verification (M&V).
For our work, the equipment we meter with data loggers includes HVAC systems, domestic hot water systems and electrical systems. In order to truly evaluate how a larger system or whole building is performing, we will generally use multiple meter types. For a lighting system, we use a meter that shows when the lights are on versus off, or a meter that logs light intensity (typically for systems that incorporate daylight dimming). For an HVAC system, we can monitor temperatures, see how often the associated equipment is running, and determine how much energy it is using to determine if the equipment is performing as intended. This information can then be compared to building control system trend data (if available) to see if the installed system instrumentation is accurate, or if parts of the system require calibration.
New Technologies and Improvements
The standard practice for deploying data loggers (often refer to as meters) has been to configure a meter on a computer using the meter vendor software, install the meter in the field, then pick it up and retrieve the data by again directly connecting the meter back to a computer. Recently, measuring device companies have been coming out with new technologies and improvements to make this process easier, more practical, more effective and safer.
Wireless Setup & Remote Real-Time Data Access
Meters can now be equipped with an optional wireless capability. This can be either Bluetooth or Wi-Fi technology (or both), and some are even equipped with cellular data capabilities (GSM). These features have several advantages over the traditional meter connection.
Using the Bluetooth technology, deployment and data retrieval from a meter can be done wirelessly within a short distance of the meter. No more cords! This also means that meter settings can be tweaked after the meter has already been installed. For example, Dent’s ELITEpro XC Power Meter can be installed on an electrical panel and meter settings can be adjusted without needing to reopen the panel door. This is a safer and faster approach to readjusting the meter’s setup information.
With wireless capabilities comes the ability to remotely access your device in real-time through a Wi-Fi connection, allowing a user to access the meter data from a computer and in some cases, a smart phone or tablet. The following are two advantages to having this feature:
- Meter data can be viewed and/or retrieved without going into the field.
- The user can periodically check the meter status to make sure it is working correctly and still logging. This will prevent surprises and/or issues with the data after a metering period is complete that can make the data suspect and not useful.
Many companies, such as eGauge, Dent Instruments, and Onset’s Hobo Data Loggers have added these wireless options to their product lines.
Larger Memory Capacity
Data logger companies have also been expanding the memory capability of their devices to allow users to collect larger quantities of data over a longer period of time. This means that a smaller time interval can be assigned to a meter (e.g., data can be collected every 5 minutes instead of every 15 minutes for the same metering period) and/or the meter can handle being in the field longer. This can make it possible to use a meter long enough to collect data for different seasons, which provides a more comprehensive set of data.
I look forward to using these new types of metering devices in our work and to seeing what other technologies will develop in the metering field. If you have had the chance to use data loggers with these capabilities or others I did not get into, please describe your experiences in the comments section.