How Do Differential Pressure Gauges affect HVAC checks?

How Do Differential Pressure Gauges affect HVAC checks?

There are a range of factors for Heating, Ventilation and Air Conditioning (HVAC) technicians need to account for, to ensure higher indoor air quality (IAQ). This includes:

  • Air flow
  • Relative humidity
  • Particulate build up

These factors have a far-reaching effect in regards to IAQ and internal comfort. It is because of this that the top technicians appreciate the range of HVAC instruments available from Testo New Zealand. One such instrument is the differential pressure gauge- but how does this work and why is it important for all HVAC checks?

How do differential pressure gauges work?

Differential pressure gauges work on the principal that high and low pressure cause a variance in levels of air flow. Almost all HVAC systems, regardless of their end application, have duct or pipe airflow. Air passing from outside to indoors is cleansed by filters within these tubes, once this air has been filtered, the pressure of the air on the downstream side of the filter will drop. This in turn will pull more air from outside into the pipe.

If the pressure is measured at points either side of the filter system, technicians are able to assess both particulates build up in the air and the condition of the air filter causing the change in pressure. A predetermined threshold is required for this process. This threshold is referred to in order to determine if the differential pressure has dropped too low. This threshold is set by technicians calculating the volume flow rate and identifying the filters physical characteristics, such as thickness.

How does pressure switch data help to improve HVAC system checks?

The primary, and most important, use of a differential pressure gauge is checking the performance of HVAC systems. A significant change in pressure measurements is the main symptom of a blocked air filter. If neglected, this will inevitably lead to a reduction in how effectively the ventilation, heating or cooling equipment works. Long term it can even cause the system to break down completely. Differential pressure readings are also indicative of more serious issues within a tube or pipe. If an air filter has been significantly damaged, for example, the above effects will happen at an exponentially faster rate, leading to costly equipment repairs or replacement even sooner. Data outside of a normal range can also indicate an issue with air flow before gasses even reach the filter. With this insight, HVAC technicians are able to make more informed decisions about system repairs and maintenance. 

Technicians are able to use pressure measurements produced by digital gauges for more than just ventilation system maintenance. HVAC specialists are also able to use the data to inform wider IAQ planning. Here are a few scenarios to consider:

  • A blocked filter inside a ventilation system may allow for contaminates to pass through the blockage, contributing to an increase of pollutant build up in your indoor space.
  • Restricted ventilation air flow can cause indoor air pressure - a restricted air stream causes a vacuum that sucks in the air from other areas in order to fill it.
  • Unbalanced differential air pressure will contribute to the HVAC system breaking down. This will have a knock-on affect to the IAQ.

We can therefore conclude the differential air pressure checks are an essential part of HVAC equipment servicing and wider IAQ assessment. With that in mind, which instruments will help make these checks easier?

Testo's digital pressure gauge

Testo are proud to develop a range of differential pressure and pressure loss solutions. These include flow measurements from water heaters, to filters in air conditioners, we have an instrument that will help technicians across a range of HVAC sector businesses.

The Testo 510 digital gauge set

 allows technicians the ability to perform measurements on a wide range of HVAC systems, from heaters to coolers to buildings’ integrated ventilation system. The Testo 510 is designed with easy transport in mind and comes equipped with rear-mounted magnets to make hands-free measurements hassle free.

Testo's 400 universal IAQ instrument

This solution is a major asset for any HVAC technicians. It is able to log and collate data on an incredibly impressive number of factors relative to IAQ and internal comfort. The end-game for all HVAC checks is to ensure that the system, no matter its function, is contributing to a more comfortable indoor environment. The Testo 400 instrument makes the process easier, allowing for multiple data measurements to be performed with the same instrument.

The Testo 440 differential pressure instrument

Testo’s 440 solution is perfect for performing differential pressure loss filter checks. Users are able to calculate flow velocity and volume flow using the internal pitot tube. Measurements are all stored in the instrument for future data analysis and documentation. It is equipped with a large screen and user-friendly menu guidance, making the Testo 440 ideal for time poor technicians.

It is impossible for a technician to fulfil all the expectations of high-quality HVAC system measurements and checks without a pressure differential gauge. For more information about Testo’s advanced line of HVAC system differential pressure gauges, get in contact today!