HVAC

Product selection & help guide for measurements on HVAC systems in buildings & laboratories.

HVAC is the acronym for Heating, Ventilation and Air Conditioning.  It is a term often used to describe a piece of equipment which is specially designed for use in an environmental control system for a building, room or a vehicle.

• Draft Pressure Sensors - Find low-pressure transducers & transmitters (inWC, mbar, Pa) designed for draft measurement in air handling, combustion control, and ventilation applications.
• HVAC Pressure Sensors - HVAC pressure sensors are essential for maintaining optimal performance and energy efficiency in heating, ventilation, and air conditioning systems.

• DPS200 HVAC Differential Pressure Transmitter
• IMPLR Low Range All Stainless Steel OEM Pressure Sensor
• DPS300 User Switchable Pressure Range, Volts or Current Output Low DP Sensor
• DPC Low Range Pressure Controller and Calibrator
• LEO Record (Ei) Capo Low Pressure Logger
• DPS Low Differential Pressure Transmitter
• 41X Low Range Digital Output Pressure Sensor
• DMP343 Low Range Pneumatic Pressure Sensor
• DS210 Combined Low Pressure Switch, Indicator and Sensor
• Clean Room Monitor for Air Differential Pressure, Temperature and Humidity – PMDS4
• DMD341 Compact Differential Air Pressure Sensor
• PrimAtü 10 Low Cost Low Range Differential Air Pressure Transducer

• 100 mbar pressure logger for monitoring natural gas pressures - Data-logger for connecting to a natural gas supply pipework which serves a number of boilers in a building.
• Refrigerant head pressure control transducer for commercial cooling systems - 225 psig pressure transducer designed for head pressure control in refrigeration systems, featuring a welded stainless steel diaphragm and a 0-10v analog output for precise variable speed fan control.
• Clean room monitoring system to measure pressure, humidity & temperature in 4 individual rooms - A complete clean room measurement system for 4 separate rooms, each with its own room pressure, humidity and air temperature indicator, and a central monitoring unit for clean room corridor or control room.
• Laboratory environment monitor for precise room pressure, temperature and humidity - Monitor and maintain critical atmospheric conditions with an integrated system featuring bi-directional pressure sensing, ambient temperature measurement, relative humidity tracking, and local relay control.
• Groundwater heat pump well monitoring using dual-parameter level and temperature probes - Dual-output 4-20mA solutions for monitoring aquifer levels and source water temperatures in open-loop geothermal systems requiring long cable runs.
• 1 hPa Positive Room Pressure Sensor, Switch & Display - A 100 Pascal range positive room pressure sensor with a 0-10 volt analogue output signal relating to the inside/outside room pressure difference.
• 3 psig range 4-20 mA output BMS natural gas or propane heater pressure sensor - A low range gauge pressure sensor for building management use to measure pressure of natural gas or propane on building heaters over a range of 0 to 3 psi g from the 1/4 NPT male process connection, and sending the corresponding 4-20mA signal through the integral cable electrical connection.
• R21/R22 refrigerant digital pressure gauge to read up to 500psi - Digital precision pressure gauge for measuring pressure from 0 to 500 psig of R12 or R22 gas which is used in refrigeration and air conditioning equipment.
• R134A Coolant Pressure Transducer For Automotive Air Conditioning - All welded voltage output pressure transducer for use on R134A refrigerant coolant gas used in automotive air conditioning systems.
• HVAC chilled water wireless pressure monitoring in BMS - Upgrade your Building Management System with a reliable wireless pressure sensing system. This case study explores the implementation of a 0-10 bar gauge wireless transducer and receiver pair for HVAC applications, highlighting the 'plug and play' installation and long-term, low-maintenance operation.
• Wireless differential pressure monitoring for room overpressure using a modbus gateway - Monitoring room pressure differentials without running new cables by utilising 4-20mA DP sensor converted into a battery-powered wireless node that integrates directly into a local SCADA system via a Modbus RS485 gateway.
• Wireless environmental sensors with custom MQTT SCADA system for energy management IoT platform - An energy management specialist required a multi-point wireless sensor network with specific accuracy requirements and a gateway that could output to their own MQTT-based SCADA system. This explains the selection of sensors and the dual gateway solution offered, covering both Modbus RTU and cellular MQTT options.

Heating, Ventilation, and Air Conditioning (HVAC) systems are critical for maintaining comfortable and safe environments in buildings and laboratories. Accurate measurement of various parameters is essential for optimizing HVAC performance, ensuring energy efficiency, and preventing costly breakdowns. This guide outlines key considerations for selecting the right measurement instrumentation for your HVAC system.

HVAC systems are employed across a diverse range of sectors, including commercial buildings, residential complexes, laboratories, hospitals, cleanrooms, and manufacturing facilities. The specific measurement needs will vary depending on the application. For instance, a hospital HVAC system will have more stringent requirements for air quality and temperature control than a typical office building. Similarly, laboratories often require precise control of humidity and airflow for sensitive experiments. HVAC technicians, building engineers, and facility managers are the primary users of this instrumentation.

When selecting measurement instrumentation for HVAC systems, several factors must be considered. Temperature is a fundamental parameter, and accurate temperature sensors are needed for monitoring air temperature, water temperature in chilled water loops, and refrigerant temperatures. Consider the temperature range, accuracy requirements, and the type of sensor best suited for the application (e.g., thermocouples, RTDs, thermistors). Humidity is another critical factor, particularly in laboratories and cleanrooms. Humidity sensors should be selected based on the desired humidity range, accuracy, and response time. Pressure measurements are crucial for monitoring airflow, duct pressure, and differential pressure across filters. Differential pressure transmitters are commonly used for filter monitoring, measuring the pressure drop across the filter. For duct pressure measurements, both static and total pressure are important. Static pressure, the pressure exerted by the air at rest, can be measured using a static pressure port. Total pressure, the sum of static and velocity pressure, is measured using a pitot tube or similar device. The difference between total and static pressure yields the velocity pressure, which is related to the air velocity in the duct. Airflow measurement is essential for balancing HVAC systems and ensuring proper ventilation. Anemometers, pitot tubes, and flow meters are used for measuring airflow in ducts and at vents. Refrigerant pressure and temperature measurements are important for diagnosing and maintaining refrigeration systems. Specific refrigerant pressure and temperature transducers are designed for these applications. Finally, don’t overlook the importance of data logging and communication capabilities. Many modern instruments offer data logging functionality and communication protocols (e.g., BACnet, Modbus) for integration with building management systems (BMS).

Questions & Answers on HVAC applications

Laboratory to hallway negative pressure

We wish to monitor the pressure in a laboratory space to insure that HVAC system is maintaining pressure at slightly negative compare to ambient and hallways.

The DPS is a low range differential pressure sensor which can measure low level negative pressure such as the ones generated between laboratory spaces and hallways.

Related Help Guides

• Measuring the difference in air pressure between rooms
• What affects the performance of low pressure sensors

Related Technical Terms

• g Effect
• inH2O – Inches of Water Column at 4 deg C Pressure Unit
• mmH2O – Millimetres of Water Column at 4 deg C Pressure Unit
• oz/in² – Ounce per Square Inch Pressure Unit
• Pa – Pascal Pressure Unit

Related Product and Application Guides

• Low Pressure Range

Related Application Questions and Answers

• Low range vacuum pressure logger for 0 to -60 inH2O g
• Argon gas compatible pressure sensor for measuring up to 100 mbar
• Using 25 mbar DP sensor on vacuum below 0.2 bar absolute
• Low range ATEX approved 100 Pascal range DP transmitter
• Biogas HDPE cover PD blower pressure sensor
• Four cleanroom zones monitoring system to measure overpressure, temperature & humidity
• Stainless steel 316L wetted parts 100 mbar ATEX pressure transmitter
• Solvent compatible +/-100mWG dp transmitter with PTFE seals
• Low delta P sensor with 200mmH2O range and response time < 5ms
• Negative room pressure monitor and logger for multiple zones

Contact us about this HVAC page to request more information, or to discuss your application requirements.