Low-cost data loggers can provide association managers and boards with information that helps save thousands of dollars in energy costs, while helping to ensure indoor air quality and occupant comfort are maintained throughout properties.
By monitoring and recording simple variables like temperature, relative humidity (RH), carbon dioxide (CO2) and light or motor on/off, data loggers can help detect and document too hot or too cold conditions, whether your property has conditions suitable for mold growth and where energy savings are available when lights are off in unoccupied areas of the building. More sophisticated measurements – such as AC current, AC voltage, power demand (kW), energy consumption (kWh), pressure and differential air pressures – provide valuable information for troubleshooting HVAC/R systems, sub-metering, building commissioning and measurement and verification of energy savings.
Data logger basics
Data loggers are battery-operated, standalone measurement tools containing a microprocessor, a memory and sensors for measuring and recording one or more variables over time. They are typically quite small, enabling them to be deployed almost anywhere throughout a condominium building or complex, with some packaged to work in outdoor environments.
Some data loggers have internal sensors, making measurements available only from the logger location, while others have sensors on external cables that allow for monitoring at a distance from the data logger. However, a logger may offer a combination of internal and external sensors, as well as external channels accepting pulse, 4-20mA or DC voltage inputs from other sensors for even greater flexibility. The loggers operate unattended for hours, days or months at a time. Specialized software is used to configure the logger (select sampling intervals, synchronize logger and computer clocks, etc.) and to offload the recorded data from the logger to a PC for graphing and analysis.
Temperature is the most common measurement required for most condominium environmental monitoring applications, as it is important in monitoring the human environment as well as equipment operation and efficiency. RH and CO2 are two other common measurements for indoor air quality (IAQ) and comfort complaint investigations. Combined temperature and RH measurements are also critical indicators of conditions that may be conducive to mold growth, which is an important concern for today’s condominium managers, boards and residents.
In addition to standalone data loggers, web-based remote monitoring systems are available, which not only measure and record a range of environmental parameters, but also make the data available on the Internet 24/7. Typically, these systems incorporate some type of wireless communications technology – including GMS cellular or Wi-Fi – and offer web-based software that enables all logger management and retrieval functions to happen over the airwaves.
Typical monitoring applications
HVAC/R troubleshooting
Airflow pressure, monitored with an external airflow pressure sensor mounted within an air duct or attached to heating coils or pipes, can provide valuable insight into heating distribution or air balance problems. Multiple airflow points may be used to evaluate a larger section of an air distribution system for larger-scale analyses along with temperature readings (at supply and return vents). In addition, time-of-use data loggers can also be used to monitor HVAC/R equipment to detect short cycling of, for example, a compressor or blower, or other equipment runtime in order to evaluate potential failures for scheduling repairs or replacements.
Chiller system efficiency is easily and accurately monitored by logging outdoor temperatures, water temperatures and flow rates at supply and returns, and when pumps are turning on.
Energy management
Data loggers can be used to track energy usage in various parts of a condominium to verify equipment-operating efficiencies and to identify areas where energy costs can be reduced.
Light usage monitoring
Total light usage in a condominium complex can gobble up a good share of power, especially if left on unnecessarily for long periods of time. Light intensity (loggers that have built-in photo sensors) or state on/off data loggers can be placed as close as possible to individual light sources or on ceilings or walls to record when lights are on over various times. Data should be logged for a period long enough to cover various times of day and night, as well as occupied and unoccupied periods. The data gathered will not only detect direct light usage but can also help in deciding whether the expense of permanently installed occupancy light sensor/switches or some other remediation is justified.
If changes are made to reduce light use (or wattage reduction), the very same loggers can be re-deployed in the same spaces later on to generate data to verify that the changes were successful.
Conclusions
Portable data loggers are inexpensive and are easily deployed measurement-recording tools that can have a positive impact on containing energy costs without sacrificing occupant comfort levels. With so many possible uses in a condominium – energy usage monitoring, verifying comfort and IAQ conditions, etc. – they may be the ultimate measurement and recording tools for balancing and managing a building’s energy usage and environmental qualities.
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Author : Evan Lubofsky
Company : Onset
Evan Lubofsky is the director of marketing for Onset.
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