HVAC Pressure Sensors

Optimized for HVAC System Requirements

Differential pressure sensors play an important role in energy conservation and ensuring HVAC systems are performing at maximum capacity. Sensors are used for measuring air pressure in many different air handling devices and applications. Some of the more common are depicted in the image below:

HVAC-compostite-illustration

HV Series Differential Pressure Sensors

The HV Series’ wide dynamic range is ideally suited to provide multiple pressure ranges in a single package, thus minimizing the number of sensor variants required to support the demanding functional requirements of the HVAC market.

Measuring dry air and non‐aggressive gas pressure, the HV has an extremely low noise floor and stable zero point, resulting in the highest levels of accuracy, steadiest long-term stability, and lowest error rates. Our unique Multi-Range technology enables the HV Series to support up to 8 pressure ranges in one device starting with pressure ranges as low as 25 pascals.

Power on time is also a consideration and with a warm‐up in the range of just a few minutes, the HV Series is an excellent choice for time-critical installation applications.

HV Series Product Matrix 2023-Q3

HV Series – Differential Pressure Sensors

HV Series

FEATURES

  • Highly integrated dual sensors with ADC and DSP
  • Selectable pressure ranges from ±0.1 to ±60 inH2O
  • Integrated 50/60Hz Notch Filter
  • Selectable bandwidth filter from 0.1Hz to 10Hz
  • Very high accuracy ±0.1% of the selected range
  • Long-term stability ±0.1% of FSS in the first year
  • Advanced digital filtering (optional)
  • Integrated closed-loop control (optional)
  • Temperature-compensated from 0°C to 50°C
  • Supply voltage compensation
  • Fully integrated compensation math
  • Standard I2C and SPI interfaces

Engineering Design Resources

CAD Design Files

3D Model & Configurator: HV Series

Select product requirements from table to see the order part number. In addition, view & download 3D Model in native CAD format.

(model download requires registration at CADENAS PARTsolutions)


90° Port Adapters

Depending on your product design, you may need the ports facing to the sides instead of the top. Superior offers highly reliable, high-quality adapters that plug into the two ports of our pressure sensors for easy implementation. With these 90° adapters, there is no need to worry about z-height.

90° adapters are available with and without o-rings:

KP-RAR: without o-rings

KP-ROR: with o-rings

Adapters are offered in packages of 50 and 1000.


Recommended NimbleSense Features for HV Series

A single device can accommodate up to eight different pressure ranges (from 25 Pa (0.1” H2O) to 15 kPa (60” H2O) across the HV Series), with each range being factory-calibrated and optimized to maintain consistent total error band, accuracy, and stability. This alleviates the complexity and complications associated with working with multiple sensors. Utilizing a Multi-Range part streamlines both the design and manufacturing process, eliminating the need for researching, purchasing, and integrating numerous parts.

Implementing the same component in all designs enhances efficiency and ease, and pressure adjustments are conveniently controlled through a single software command. Moreover, Multi-Range provides the added benefit of a singular inventory item, adding value and convenience to manufacturing operations. In summary, the value of Multi-Range is apparent to both design and manufacturing teams alike.

HV160 Multi-Range Comparison

Benefits of Multi-Range Technology include:

  1. Design flexibility with the ability to adjust pressure range throughout the development cycle
  2. Simplified product design with one sensor replacing up to 8 different sensors
  3. Ability to quickly develop product variants at different pressure ranges without changing hardware design
  4. Greater economies of scale by purchasing larger quantities of the same product
  5. Reduced manufacturing complexity and costs due to simplified calibration of sensors
  6. Up to 8x reduction in sensor inventory costs and product obsolescence
  7. Allows manufacturers to build fewer product variants, significantly lowering working capital requirements and inventory

By directly controlling motors, valves, and actuators, closed-loop control enhances the ability to establish and sustain flow rates through pressure management. Superior provides the option to integrate this capability into the sensor, allowing for more efficient control of flow rates and maintenance of flow rate targets.

Basic Control Loop System

Superior’s integrated closed-loop control design considerably reduces loop delays in electronic circuits by up to 100 times. This solution also removes the requirement to develop a complex, external control loop system, leading to more efficient, reliable, and cost-effective products. The benefits of an integrated closed-loop control cannot be overstated, especially in medical respiratory devices such as CPAP, HVAC systems, UAVs, and in products for measuring air quality.

Displayed in the diagram below is a block layout depicting the implementation of a superior closed-loop control system for an air quality application. For accurate measurement of air quality, it is essential to uphold a steady and predetermined airflow through the viewing window. The differential pressure measured across the venturi serves as a direct indication of the flow entering the viewing window. By setting a target pressure level across the venturi, the differential pressure sensor automatically adjusts the pump drive, up or down, to maintain the aimed differential pressure and sustain an even airflow into the viewing window. The utilization of the NimbleSense closed loop circuit, in combination with the company’s exclusive noise filtering technology, successfully reduced loop delay by more than 100 times.

CLC flow

Benefits of the integrated closed-loop control include:

  1. Greatly reduce loop delays to improve the accuracy and responsiveness of your product
  2. Improve the reliability of your product by eliminating discrete parts
  3. Reduce your overall system costs
  4. Minimize system power and heat
  5. Simplify your product design
  6. Speed your time to market

Superior’s cutting-edge digital filter is a multi-order filter that leverages advanced filtering capabilities at the front end of the sub-system to eradicate critical noise caused by fans, blowers, or other dry air/gas sources before they reach the pressure-sensing sub-system. This is accomplished using the NimbleSense advanced filtering capability, which eliminates sensor-induced mechanical noise before it becomes an error signal that can negatively impact overall system performance. By replacing a competing component in customer deployments, our sensor has produced a more than 10-fold reduction in sensor-induced noise, significantly enhancing the SNR of the sensor output. This improvement is even more substantial in very low-pressure systems.

By incorporating both standard and optional digital filters, this feature offers considerably better noise reduction and eliminates the need to design an external filtering system, leading to more efficient, reliable, and cost-effective products. Our advanced digital filtering is fine-tuned for each application to ensure that mixed sampling noise is well below the noise floor. By eradicating mechanical noise, we maximize the overall performance of the system.

Below is an example of a 4th-order FIR filter that has been specifically designed to eliminate pump noise above 50 Hz, which has an equal magnitude of noise as the signal being monitored. The graphs illustrate the outcome of Superior’s advanced digital filter.

Updated ADF transfer
Updated-ADF-1024x343

Benefits of the advanced digital filtering technology include:

  1. Greatly reduced system noise levels by 10x or more, especially important in very low pressure applications. For noise prone systems, an improvement of 100x to 1000x is not unreasonable.
  2. Eliminate noise sources such as fans and blowers before they reach the pressure sensing sub-system.
  3. Simplify product design with an integrated approach.
  4. Speed time to market by not having to design an external filtering system.

Superior’s pressure sensors have an exceptionally low noise floor, which can make it possible to detect power line interference during measurements. However, with the inclusion of an integrated 50Hz/60Hz notch filter, this noise is effectively eliminated. As a result, users are able to maintain the advantage of using a pressure sensor with an ultra-low noise floor, without any external interference. Additionally, the seamless integration of the notch filter into the sensor module ensures that the interference caused by these frequencies is blocked out before it reaches the user’s application. With the notch filter already built into the sensor module, there is no longer any need for engineers to design and implement an external notch filter. As a result, this feature promotes greater system efficiency, reliability, and cost-effectiveness by removing the need for external filters.

Benefits of the integrated 50/60Hz Notch Filter include:

  1. Eliminate the noise from the power grid and AC devices before it reaches the sensing element
  2. Simplify product design with an integrated approach
  3. Speed time to market by not having to design and/or implement an external notch filter
  4. Lower overall system cost as an external notch filter is no longer required

A pressure switch is a mechanical or electronic device that is activated when a certain pressure threshold or set point is reached. These failsafe response components instruct the system to perform an action if a certain pressure threshold is met.

Types of Pressure Switches

Fixed Pressure Switches

As their name implies, fixed pressure switches have pre-set, non-changeable pressure thresholds that are set by the pressure switch manufacturer. The device maker receives the pressure switch already configured and cannot change values. Examples where fixed pressure switches are common are certain types of medical devices, such as ventilators.

Variable Pressure Switches

With variable pressure switches, the threshold value can be set either by the device maker or dynamically in the field. If it is controlled by the device maker, when they build their product they select certain resistor pairs that control the voltage input that determines the threshold. Once they build the product, the threshold value cannot be changed.

In cases where the threshold can be set in the field, this is typically done via software or a mechanical knob/switch. In this scenario, the pressure switch is usually not implemented as a safety feature. A good example is with air filters – where depending on the system implementation, the threshold value needs to be adjusted to account for any head loss in the flow stream.

Superior’s pressure switch changes state depending on the measured pressure being above or below a certain threshold. This can be used as a fast response failsafe feature for overpressure conditions, and to provide other simplified on/off system feedback. However, unlike other more common pressure switches, the Superior Sensor pressure switch includes three modes for setting threshold pressure, one fixed and two variable:

  • Fixed mode: Superior Sensor Technology sets the threshold and provides the ‘ready for use’ configured sensor (with integrated pressure switch) to the device manufacturer.
  • Variable mode 1: The device manufacturer can configure and set the proper thresholds at the time of product manufacturing.
  • Variable mode 2: Pressure thresholds are field programmable via software, so the pressure switch can be ‘tuned’ after product manufacture depending on the use case.

Benefits of Superior’s integrated pressure switch include:

  1. Flexibility with 3 modes of operation
  2. Lower system cost as the need for an external pressure switch is eliminated
  3. Smaller overall PCB footprint
  4. Improve the reliability of your product by eliminating external components
  5. Minimize system power and heat
  6. Simplify your product design
  7. Speed your time to market

Video Corner

HVAC Applications Video

HV Series Benefits Summary