Energy & Resource Solutions, Inc. is a Massachusetts-based energy engineering firm whose goal is to help clients solve complex energy and resource problems.
AL Senior Engineer Chris Schmidt and Engineering Director Jon Maxwell are involved in a number of large engineering projects and studies addressing energy and resource conservation in the United States. They recently shared with us their experience and expertise on trends in energy assessment, data loggers U12-012, U12-013, UX120-006M, U12-008 and their role in the energy performance monitoring industry.
Q1: What are some of the trends you are seeing in Energy Monitor?
Jon: With all the different LEED credits and related mv requirements and opportunities for corporate tax incentives in reducing energy consumption, we're seeing more and more demand for metering. Companies are looking for more ways to estimate cost savings and justify their energy efficiency investments.
Chris: Beyond that, we're seeing more and more requests to monitor the impact of sustainability programs. Furthermore, in recent years, building commissioning has become a big industry that requires data. Both of these trends drive a greater need to invest in data logging equipment.
Question 2: Describe a common missed opportunity in an industrial energy saving environment.
Chris: When Air Compressors are not performing properly, they can be a huge waste of energy. The type of controls and control settings have a major impact on the energy use of an Air Compressor, so there are often many opportunities for energy savings. One of the effective means to describe and quantify these opportunities is through the use of data loggers.
However, over the years, we've seen a lot of misconceptions about how to monitor an Air Compressor. Many people don't realize that the control mode of their compressor to operate and monitor intervals should be that of an Air Compressor or process machine tool. Many use time intervals (5 minutes) to capture the energy used by compressors over longer periods of time (at least a week), which is of course important. However, Air Compressors can have frequent changes in the rate of power consumption, so the data sampling interval should be set so that you can capture the change.
Jon: For example Chris, in a recent project, we used two HOBOU12-012, U12-013, UX120-006M, U12-008 data loggers to record the current screw Air Compressor compressed air flow sensor T -CDI-5200-10S, T-CDI-5400-20S. A logger has a fast sample second. Loggers fill up the day, but it enables us to understand the peculiarities of the cyclic system.
In the meantime, we installed a second logger and collected data at five-minute intervals for two weeks. This shows the entire load. Together, U12-012, U12-013, UX120-006M, U12-008 give us a better understanding of compressor performance so we can accurately estimate existing energy usage and predict savings potential. In this particular case, the savings would result in a change in the sequence control preventing both compressors from being modulated simultaneously.
This method is also suitable for many other types of equipment with high frequency change rates.
Question #3: Which ones should be considered when monitoring current?
Jon: When monitoring relatively constant loads, finding true power or power factor measurements combined with current logs can be a very cost-effective approach.
Current logging can be used in many applications even if the load varies. The key is proper voltage and power factor. The voltage part sounds simple enough, but in person we perform a lot of 3rd party metering and often see comment analysis, using current logger readings with the standard nameplate 460V, not the actual line voltage around 480V.
Chris: The power factor power sensor T-VER-8044-100 varies as a function of both motor size and loading, which makes true power monitoring desirable under variable load conditions, but this is not always practical. Due to cost constraints and sometimes physical limitations, the panel would not hold the three CTs current sensors CTV-A, CTV-B, CTV-C, CTV-D, CTV-E and Recorder.
The good news is that the relationship between power factor and current is fairly predictable. At MAN, we have developed custom algorithms to calculate power factor at any load. The algorithm considers point voltage voltage sensors T-CON-ACT-150, T-CON-ACT-300, motor nameplate current current sensors CTV-A, CTV-B, CTV-C, CTV-D, CTV-E and voltage.
Jon: When monitoring variable frequency drives, we always measure the drive on the line rather than the load.
Question #4: Have data loggers improved the way you gather information?
Jon: The cost of logging hardware has come down, and software interfaces have improved dramatically. These two factors also reduce metering costs per point.
This allows us to meter more devices at each site and meter more desirable parameters (kW, flow) than before. Furthermore, accessing the first cell migration data from dial-up remote, now networked media has improved our ability to perform long-term measurements.
Question #5: Thoughts on closing?
Jon: When the people team started to conduct energy audits, the average cost benefit cost savings we were able to identify was between 10 and 20% of the total usage. After nearly 20 years of customers performing upgrades, market transitions, code changes, etc., when we do energy audits today, we still find potential for savings of 10 to 20%. That's not because nothing about the plants has changed. it has.
Management has been investing in efficiency. But new technology, lower equipment costs, and higher energy rates mean there's plenty at your fingertips. This is exciting and heralds the future of our industry. Sometimes it's different from previous missed opportunities, but they sure are.
