What is BTU Meter for Chilled Water?

The BTU Meter for Chilled Water accurately measures the thermal energy consumed by chilled water in British Thermal Units (BTU). This is a basic measure of thermal energy in commercial and residential buildings. BTU meters are used in chilled water systems in commercial, industrial and office buildings.

BTU Meter for Chilled Water is to install a pair of temperature sensors on the ascending pipe and descending pipe passing through the heat transfer fluid respectively. The flow meter is installed on the fluid inlet or return line. The integrator collects signals from flow and temperature sensors. Use the cumulative formula to calculate the amount of cold and heat obtained by the heat exchange system.

BTU Meter for Chilled Water

BTU Meter in Chilled Water System

BTU Meter for Chilled Water consists of a flow measurement sensor, two temperature sensors and a microprocessor based energy calculator.

The flow sensor should be installed in the chilled water return line, and the chilled water flow direction should be installed in a vertical or horizontal position.

Two temperature sensors. A sensor is installed on the return line. The second sensor is installed on the water supply line.

The thermal energy transferred from the cooling water to the consumer over a defined period of time is proportional to the temperature difference between the flow and return flow and the amount of cooling water flowing through.

Sino-Inst offers two types of BTU Meter for Chilled Water. One uses ultrasonic measurement technology (ultrasonic BTU meter). Another uses the electromagnetic principle (electromagnetic cold and heat meter).

Extended Reading: 3 inch (3″) Water Flow Meter

Ultrasonic BTU meter is an intelligent heat metering device. Realize accurate measurement of cold and heat. It is used in heating facilities with heat metering and charging such as central heating, central air conditioning and combined cooling and heating.

Working principle

The Ultrasonic BTU meter measures the liquid flow in a circular tube based on the velocity difference method.

This series of instruments adopts advanced micro-power digital design technology such as digital transmission, digital reception, digital analysis, and digital output. The meter is accurate in measurement, reliable in operation, and more suitable for the needs of industrial sites.

Converter forms are: wall-mounted, panel-mounted, integrated;

The sensor forms are: plug-in type, pipe segment type, and outer clamp type.

Extended Reading: Wireless Water Meter

Ultrasonic heat and cold meter product features:

  1. Transducer: As the main signal generating component in the ultrasonic heat meter. Imported piezoelectric ceramic sheets are used. Stable performance and good consistency. Ensure that the ultrasonic heat meter achieves high-precision measurement.
  2. Temperature sensor: PT1000 high-precision platinum resistance is used. And configure the precision measurement circuit. Guaranteed high-precision temperature measurement.
  3. Self-diagnosis function: the ultrasonic heat meter is in stable operation. In case of abnormal communication, insufficient power or human sabotage. The system will display the corresponding code. The system automatically saves the data. Wait for the troubleshooting to recover.
  4. Remote transmission and centralized control function: with M-BUS, 485 interface. It can realize remote data transmission and centralized control.
  5. Beautiful appearance, can be hung in any direction in four directions. Easy to read and easy to operate.
  6. Easy to install. It has the functions of dust-proof, moisture-proof, waterproof, anti-disassembly and vandalism.

To choose the right ultrasonic flowmeter.

Compared with other types of heat meters, the electromagnetic heat meter is more stable and reliable in measurement. The LCD screen simultaneously displays parameters such as cumulative heat, cumulative flow, instantaneous heat, instantaneous flow, inlet water temperature, outlet water temperature, and temperature difference.

The measurement flow range is wide, and the flow velocity can be arbitrarily set within the range of 0.3m/s ~ 10m/s. With pluggable EPROM, it can store flowmeter configuration parameters and flow and heat detection data. Data is not lost when power is lost.

Electromagnetic sensor polytetrafluoroethylene PTFE (130℃), polyperfluoroethylene propylene F46 (180℃), high temperature resistant silicone fluorine rubber (250℃) for users to choose.

The parameter units displayed on the LCD screen are:
The optional display units of instantaneous flow are: m3/h, m3/m, m3/s, L/h, L/m, L/s, G/h, G/m, G/s.
The optional display unit of cumulative flow is m3, L, G, etc.
Note: G is imperial unit: gallon.
The unit of temperature is °C, and the unit of heat is KJ;
The electromagnetic heat meter is equipped with RS485 (MODBUSE protocol) as standard, and HART protocol can also be selected.

Measurement principle:

The split type electromagnetic heat meter is based on the flow signal of the flow sensor in the system and the temperature signal of the supply and return water detected by the paired temperature sensor. And the time the water has flown calculates and displays the heat released or absorbed by the system. The heat is displayed in cumulative form, the unit is kWh, and the large display is 8 digits.

The calculation mathematical model is: Q=qmΔhdt

Q—heat released: kJ;
qm—the mass of the heat-carrying liquid flowing through the heat meter: kg/s;
Δh—the difference between the specific enthalpy of the heat transfer liquid corresponding to the inlet temperature and the outlet temperature in the heat exchange circuit: kJ/kg;
t—time: s.

To choose the right electromagnetic flowmeter.

BTU Meter Installation in Chilled Water System

With the increase of large buildings and modern buildings, the cooling system has developed rapidly. The demand for cooling capacity of industry and its chemical industry has also promoted the development of central cooling. Central cooling means that the power plant uses the cooling medium (usually fresh water and salt water) to supply the cooling capacity of the refrigerator to the user. In order to manage and account for the operation of refrigeration equipment. Settling the cooling energy consumed by the user. It is necessary to measure the cooling capacity of the relevant nodes.

The method of measuring the cooling capacity of chilled water is the same as that of hot water. The amount of cooling supplied can be seen as negative heat. Just due to the low temperature of the fluid. lead to some differences in specific practices.

BTU Meter Installation in Chilled Water System

Extended reading: Magnetic water meter-ultrasonic water meter-mechanical water meter

For chilled water used in air conditioners, the water temperature level is generally 5-6 °C. The cold medium is fresh water. For cooling below 5°C, use brine or other cooling media. The cold measurement method of fresh water chilled water mostly adopts the measurement method based on mass flow as shown in the figure below.

In the flow measurement of chilled water, the electromagnetic flowmeter has obvious advantages, and its characteristics are as follows:

  • Magnetic flowmeter measurements are not affected by changes in fluid density, viscosity, temperature, pressure and conductivity.
  • The electromagnetic flowmeter measuring tube has no obstructing flow parts, no pressure loss, and low requirements for straight pipe sections.
  • The electromagnetic flowmeter sensor can be equipped with a ground electrode to achieve good grounding of the instrument.
  • The electromagnetic flowmeter sensor adopts advanced processing technology, so that the instrument has a good ability to resist negative pressure.

In addition to the electromagnetic flowmeter measurement, the ultrasonic flowmeter can also be used for measurement. Customers can choose according to on-site conditions.

Extended reading: Dam water level measurement

BTU Meter Calculation

The BTU (British Thermal Unit) is universally accepted as a unit of heat transfer measurement. The BTU is defined as the quantity of heat required to raise the temperature of one pound of water 1°F. The equation for heat transfer to a liquid is as follows:


Q=Heat transfer per unit time (BTU/hr)
W=Mass flow rate (lb/hr)
T2=Outlet temperature (°F)
T1= Inlet temperature (°F)
Cp=Specific heat capacity (1.0 BTU/lb for water)

Tools: BTU Calculator & BTU Formulas For Water Circulating Heat Transfer

BTU Meter vs Flow Meter

What is a BTU Meter?

BTU meters are flow meters with temperature sensors added to measure the energy consumption of any liquid heating or cooling system. BTU meters are also known as energy meters, heat meters. Commonly used are electromagnetic energy meters and ultrasonic energy meters. It is widely used in online metering of central air-conditioning cooling and heating energy metering and heating network. It can also be used to measure the performance of energy conservation measures or the loss of system efficiency that affects revenue. Read more about: What is BTU?

What is a Flow Meter?

A flow meter (or flow sensor) is an instrument used to measure linear, nonlinear,mass or volumetric flow rate of a liquid or a gas.When choosing flow meters,one should consider such intangible factors as familiarity of plant personnel,their experience with calibration and maintenance, spare parts availability,and mean time between failure history, etc., at the particular plant site.

Extended reading: Ultrasonic water meter working principle


Flow meters measure flow, and heat meters measure heat. The heat meter consists of an integrator (calculator), a flow meter, and a pair of temperature sensors. The first detection is the supply/return water temperature and flow rate, and then the integrator is used to calculate the heat. The basic principle is Q=Cm△t.

Extended Reading: Guide and Selection for Diesel Fuel Flow Meters

BTU Meter adds accessories such as thermometer and totalizer to the flowmeter. So the cost of BTU Meter will be higher than that of flow meter.
The price of the specific BTU Meter needs to be determined by the customer’s detailed measurement parameters.

Extended reading: Ultrasonic flow detectors types

BTU, short for British Thermal Unit, is a unit of measurement that shows how much energy your air conditioner uses to remove heat from your home in an hour. This may seem overly technical, but BTU is an important metric that can help you determine the type of air conditioner you need for a home of your size.

Extended reading:  Tri Clamp Sanitary Thermometers

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Sino-Inst offers over 10 BTU Meter for Chilled Water. About 50% of these are magnetic flow meters, 40% is the ultrasonic flow sensor, and 20% are other flow meter.

A wide variety of BTU Meter for Chilled Water options are available to you, such as free samples, paid samples.

Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

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