Heat cost allocators are devices attached to individual radiators in buildings that measure the total heat output of the individual radiator. Heat cost allocators can be either electronic, where one or two electronic thermosensors[1] and a microcontroller are used to calculate the heat consumption of radiator by the temperature difference between the radiator and the air in room,[2][3] or evaporative, where a special, calibrated liquid in a capillary tube records the total heat absorbed from the air (for which an average allowance is made) in addition to that output by the radiator.
Working principle:
As the radiator heats up, the back section also heats up. The temperature (or the temperature difference to room temperature for electronic two-sensor devices) is integrated over the heating period (one year according to the heating costs ordinance) and thus forms the measured value. Since the amount of heat emitted also depends on the size and type of radiator and the heat transfer between the radiator and the heat cost allocator, the measured value of each radiator is multiplied by an individual factor. This can be done in the heating bill. One then speaks of a unit scale, because every heat cost allocator is equipped with the same scale. If, on the other hand, the heat cost allocators on different radiators are equipped with different scales, so-called product scales, no conversion takes place because the factor has already been taken into account by the choice of scale. With electronic heat cost allocators, the scaling is achieved through programming. The evaluation factor is determined when the heat cost allocator is installed. For this purpose, the manufacturer and type of the radiator - as far as possible - are determined and measurements are taken. This leads to the radiator performance as the first part of the evaluation factor. The factor is then corrected by the so-called Kc value, which describes the heat transfer between the heating medium, ultimately the radiator, and the heat cost allocator. The radiator evaluation requires the knowledge of precise data about the heat cost allocator used and the radiator, which are obtained in extensive series of measurements and tests.
How do you read a heat cost allocator?
The heat cost allocator with optical communication interface can be read on site using an infrared adapter and a suitable computer and the data can be archived for later evaluation. Wireless heat cost allocators send parallel AMR and walk-by data telegrams in S-mode or C- mode.
How do you read a heat cost allocator?
The heat cost allocator with optical communication interface can be read on site using an infrared adapter and a suitable computer and the data can be archived for later evaluation. Wireless heat cost allocators send parallel AMR and walk-by data telegrams in S-mode or C- mode.
Products and reference designs of Heat meter
Measurement
Heat Cost Allocators use a temperature sensor to measure the temperature of the room radiator and a second sensor to measure the ambient room temperature. The sensors are typically read once every 30 seconds. Measurement includes Digital temperature sensors, the corresponding products are TMP110、TMP119、TMP4718
Application processor
Heat cost allocators require a host microcontroller to calculate the temperature differential between incoming and outgoing heat flow, to control the segment display and to execute all required communications stacks. Low power consumption is a critical concern in this battery-powered application. Application processor includes MSP430 microcontrollers, the corresponding products are MSP430F5438A、MSP430FR4133、MSP430FR6989
Anti-tamper
Heat Cost Allocators monitor for potential tampering for safety purposes and to assure accurate billing. Many different types of sensors can be used to detect tampering. Anti-tamper includes Signal conditioners, the corresponding products are AFE3010
Power supply
Heat Cost Allocators have digital, analog, and RF blocks with individual DC power requirements. Depending power levels TI has DC/DC converters, LDOs and power management ICs (PMIC) that can help to reduce power dissipation and size in the solution. Power supply includes Boost converters (integrated switch)、Buck converters (integrated switch), the corresponding products are TPS61299、TPS61030、TPS62730、TPS62840、TPS629203
Wireless communication
Wireless communication is required in heat cost allocators as the link to a local data collector. Wireless M-BUS is the most common standards-based protocol used in this applications. Many vendors also offer their own proprietary solution. IR communications are required for interfacing to handheld reading equipment. Near field communications (NFC) is an alternate solution for easy, ultra-low-power connection with smart phones and tablets. Wireless communication includes Sub-1 GHz transceivers、Other wireless products、Low-power 2.4-GHz products、Sub-1 GHz wireless MCUs, the corresponding products are CC1120、CC1125、CC1200、RF430CL330H、CC2651R3、CC1312R
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