Basic Data Logging Equipment (33 kb pdf)
There are basic pieces of equipment that are needed to collect data for analysis and reference:  a data logger, cables for programming and downloading data, a software interface for logger programming and data graphing, as well as an external power supply if needed.

Monitoring Ambient Temp / RH Readings (38 kb)
To monitor and record ambient temperature and humidity for reference, it is best to shield sensors to ensure that direct sun light or water do not come in contact with the sensors.  Also, from these readings, dew point can be calculated.

Monitoring Chiller Performance (40 kb)
Chillers provide chilled water to the air handlers that are responsible for space conditioning.  They consume large amounts of energy and so should be operated as efficiently as possible.  In general, the power consumption the chilled water temperatures, and the condenser water temperatures are monitored to determine if they are operating according to their design intent, and if any changes can be made to increase their efficiency.

Monitoring Cooling Towers (39 kb)
Cooling towers provide heat rejection for chillers.  If a cooling tower is working properly, the sump temperature will be low and the chiller will work as efficiently as possible.  Cooling towers, by themselves, do not consume a lot of energy, but if they're operating inefficiently, the chillers will consume far more energy.  Measuring the cooling tower inlet and outlet temperatures, the outdoor wet bulb temperature, and fan electrical power will give you the data required to determine how well your cooling tower is operating.

Monitoring Thermal Storage Performance (40 kb)
Thermal storage systems will shift large amounts of demand from the middle of the day to night-time hours when electricity is often cheaper.  Keeping that chiller off during the day will avoid demand charges and high energy bills.  Since thermal storage systems vary in design, it is hard to generalize the methods for monitoring them.  Regardless of the system type, it's important to confirm that the actual delivered capacity of the system is maintained at its design level.

Monitoring Compressors and Condensers (42 kb)
Compressors are used in HVAC and refrigeration applications.  Their energy consumption can be inexpensively monitored with CTs, or more accurately with WattNodes.  Knowing how much energy they consume can help determine if they are consuming excessive amounts of electricity.

Monitoring Plug Loads (37 kb)
Plug load monitoring can identify how much electricity appliances are using.  Types of plug loads that are often monitored are refrigerators, electric dryers, computers, and home entertainment systems.  Plug load monitoring can identify large amounts of electricity that are consumed even when the appliances are turned off.  WattNodes and/or CTs can be used for this monitoring.

Monitoring Power (WattNode A Model, 48 kb)
Monitoring Power (WattNode B Model, 50 kb)
Monitoring electrical power consumption is key to understanding how your equipment and buildings are using energy. Whole-building power monitoring using WattNodes (fill in whatever you want here) will show how much energy is being used when the building is unoccupied, if there are large peaks that contribute to high demand charges, and in general, when power is being used. Once you know more about your energy usage, you can often take easy steps to reduce demand and substantially reduce demand charges. Similarly, by knowing about off-hours energy usage, you can start to turn off unneeded loads and save energy and money.

Monitoring Zones: Fan Coils (36 kb)
Fan coil units are often used for institutional and educational heating and cooling applications.  They often consist of hot water and chilled water coils and an air circulation fan.  If they are overheating or overcooling a space, are running when there is no load, i.e., during unoccupied hours, or operating incorrectly, they will use excessive energy.  Measuring the fan status the zone temperature, and inlet and outlet air temperatures will provide a lot of information that can be used to determine if they're working properly.

Monitoring Zones: Heat Pumps (36 kb)
Heat pumps are often used for individual zone heating and cooling applications.  In a large building, they are usually connected to a water loop maintained at a constant temperature.  If this water loop is too hot in the summer or too cold in the winter, the heat pumps will use excessive energy.  Measuring the compressor status, the water loop temperatures, and inlet and outlet air temperatures will provide a lot of information that can be used to determine if the heat pumps are working properly.

Monitoring Zones: HVAC Roof Top Units (37 kb)
A large percentage of all commercial cooling is provided by packaged roof top units(RTUs). These units often do not operate as efficiently as expected, and through monitoring the performance of the economizer and compressors, they can be tuned up to operate as efficiently as possible. Economizers can be evaluated by measuring outdoor, mixed, and return temperatures. Supply temperature and whole unit power or current will provide information about run time and overall health of the RTU.