Accurate Thermal Metering Using Non-Invasive Technology For Building HVAC Energy Management

Non-invasive ultrasonic volumetric flow meter with temperature measurement for HVAC metering
Ultrasonic flowmeter specially configured for
thermal energy metering
Courtesy Flexim
The modern business climate has, for some now, been spooling up demand for accountability and, even more so, efficiency. Whether you think of efficiency as "doing more with less" or just avoiding the waste of financial, human, or natural resources the end result is the same and calls for similar prerequisites.

We live in a society of buildings, each with a mapped out function. Most buildings are predominantly occupied by people, bringing a requirement to maintain temperature, relative humidity, and air quality at levels of suitable comfort for human occupants. The energy consumption involved with providing that level of comfort stands as a bold line item in the operating expense ledger for any building. That is where accountability and efficiency come in. It is in the building stakeholders' interest to have knowledge regarding rates and quantity of thermal energy usage, as well as efficiency measures of delivered output per unit of input energy.

HVAC (Heating, Ventilation, Air Conditioning) primarily is an endeavor that generates and moves thermal energy throughout an enclosed space. Commercially available technology now allows a building operator to accurately measure that movement of thermal energy throughout a system or building. The process is generally called BTU metering and has a number of justifiable benefits.

  • Real time equipment performance measurement.
  • Sub metering can indicate specific areas of consumption.
  • Ability to directly bill multiple tenants in a single building for their thermal energy usage.
  • Monitor and balance energy flows.

BTU metering essentially involves inlet and outlet temperature measurement of heat transfer liquids, along with their flow rate. While the principle is simple, the intricacies of the measurement methods and equipment accuracy can have a substantial impact on the accuracy, and thus the benefit, of the measurement data. Additionally, adding more instrumentation to an already complex system can create an additional on-going maintenance and calibration burden to retain the necessary levels of accuracy and function. Success at gaining the benefit of the performance data while minimizing the additional maintenance burden due to the instrumentation should be the goal.

One solution calls for the use of clamp on ultrasonic flow meters to measure liquid flow, coupled with temperature measurement in a single unit that will perform necessary calculations and provide output data in useful engineering units. An overarching benefit of the clamp on meter is its non-invasive nature, allowing its retrofit to in-place systems with no disturbance to existing piping. Here are some other characteristics of a highly effective BTU measurement unit:
  • No wear mechanism as part of the flow measurement unit
  • Traceable accuracy of flow and temperature measurements
  • Simple installation in new or retrofit applications without disruption to system operation
  • Reliable and maintenance free operation
  • Accurate measurement from near zero flow rate to maximum system flow
  • Stable sensing with no zero drift
  • Communications protocol to match building energy management system
  • Large storage cache for data, in case of communication failure
  • Common output signals, 4-20 ma or other, usable with selected ancillary equipment
Selecting the right equipment or instrumentation is the most important step along the path of adding measurement capability to increase efficiency. Without a solid stream of reliable data, useful decisions become difficult. Contact a product application specialist and share your requirements and goals. Combining your process and system knowledge with their product application expertise will produce a good outcome.


Selecting Single-ended vs. Differential Voltage Measurement for Process Measurement - Part 2 of 2

programmable logic controller with input and output devices for process control
Selecting the proper signal conditioning equipment
is essential to maintaining process operation
This second part of a two part series of white papers provides discussion of the differences in function of differential and single-ended voltage measurement for industrial process measurement and control. Part One focused primarily on single-ended voltage measurement, how it differs from differential, and in what application context it can be best applied. This white paper, provided below, delves into differential voltage measurement and how it may be advantageous, even necessary, in a range of application scenarios.

The papers are produced by Acromag, Inc., a globally recognized manufacturer of signal conditioning equipment. Information about Acromag's extensive product offering is available from M.S. Jacobs & Associates, as well as technical details and application assistance.



Selecting Single-ended vs. Differential Voltage Measurement for Process Measurement - Part 1 of 2

DIN rail mounted process measurement signal conditioning module
Acromag manufactures an extensive array
of signal conditioning modules
Process control requires process measurement. The industry provides a enormous array of measuring devices for almost every conceivable process parameter. Selecting the right signal conditioner that will convert a current process state into a signal to be transmitted to and utilized by a controller can be challenging. One area of confusion centers around whether to use differential or single-ended voltage measurement.

Acromag, Inc., a globally recognized manufacturer of signal conditioning equipment for industrial process measurement and control, has provided a white paper that helps sort out reasons behind a beneficial selection of single-ended or differential voltage measurement devices. Explanation of how each functions and tips on selection criteria for an application are also provided. The technicality of the language is at a level that is comprehensible to most, but retains that exciting engineering edge for the purists among us. The first part of two (Part Two), provided below, focuses mostly on single-ended measurement. Part two covers differential.

Top flight assistance with your process measurement and control application challenges is available from M.S. Jacobs & Associates.



Get To Know MS Jacobs & Associates for Industrial Process Control Instruments and Equipment

Electric power generation plant
MS Jacobs serves the electric power generation industry,
as well as chemical, oil and gas, water and wastewater
M.S. Jacobs and Associates has been a leading manufacturer's representative and distributor of industrial instrumentation and controls since 1945.  Expanding from its original focus on the steel industry, MS Jacobs services and supplies products in all major industrial markets, including power generation, chemical processing, pulp and paper, oil and gas production, water and wastewater treatment, and nuclear power generation.

The company's longevity and dedication to the industrial market has resulted in a broad offering of superior quality products for flow, level, pressure, and temperature measurement, as well as filtration products and valves. Everyone at MS Jacobs takes pride in the company's ability to solve tough applications and provide exceptional customer service with a team of trained outside sales engineers and inside customer service representatives.

MS Jacobs' Pittsburgh service center provides instrument calibration and repair for MSJ's complete line of products, as well as those of other manufacturers. The company carries factory authorization for repair of numerous manufacturers' industrial process instrumentation products. The service center also provides custom assembly of instruments and other gear to meet customer requirements. Completed assemblies are tested and certified prior to shipment.

Reach out to MS Jacobs & Associates for the products and services that move your process instrumentation and control projects toward a successful completion.