Why Using Pressure Sensor

for HVAC/R Systems

For effectively reducing energy cost of an HVAC/R system, one of the feasible ways is to operate the system at a power level truly reflecting the system's actual need. In the past, once there was a demand for cooling, a pressure on/off device would indicate such demand to the system, and hence the system would run at 100% power consumption with the highest amount of energy. This implied that a significant amount of energy would be squandered.
To deploy smarter control, pressure sensors will be used. This is to say, if there is a demand which requires only 40% power consumption, the pressure sensor will feed the relevant data to cooling drive unit and the whole HVAC/R system will only consume 40% power, leading to much less energy waste.

Requirements of Pressure Sensor

Applied to HVAC/R Systems

A robust pressure sensor shall be able to provide accurate signals even at demanding conditions. HVAC/R systems are usually installed on roof tops of buildings, where occurrences of extreme outdoor temperature and humidity are always found. Therefore the pressure sensor shall be able to withstand such ambience when being used.

The pressure sensor shall be designed with airtight seal for prevention of leaks. This is particularly critical when the sensor is operating with refrigerants used in the HVAC/R system, where leaking is prohibited so as to reduce the amount of refrigerant be released into the atmosphere.

HVAC/R systems are extremely repetitive and can cause a high number of cycles to be placed on the equipment. Thus the pressure sensors must be able maintain high accuracy through many operation cycles over a very long lifetime.

Features and Benefits

of Avery Instrument AV300

● A +/- 0.25% accuracy and +/- 0.2% stability across a wide operating temperature range.
● Measure liquids and gases with pressure ranges from 0-1 PSI to 0-1000 PSI (70 bar)
● Media isolated design and rugged construction to handle excessive shocks and vibrations, and to protect against moisture ingress
● RFI and EMI protection available for clear uninterrupted signal in harsh electrical environments
● 316L as wetted material and stainless steel as body material for better withstanding harsh chemicals and gases
● Sealed to IP65 rating
● Thermally compensated range from 0 to 70℃, providing consistent performance under wide temperature ranges
● Applicable to HVAC/R systems, boiler controls and pressure instrumentation, etc.