Refrigerant Manifold Gauges: Digital vs. Mechanical

A manifold is an essential tool for any HVAC technician performing their trade on an air conditioning system. The manifold primarily measures the low and high side pressure of the system, which then gives the user useful information to diagnose the system. Which type of refrigeration manifold gauge do you commonly use — digital or mechanical? Each type has its advantages and disadvantages.

1. Reading the numbers
Given that space on the gauge is limited, some of the dials will be printed smaller (to fit all of the dials in there) therefore making it tougher for the user to get a good read on the mechanical manifold. The digital manifold has a digital display, that will show you the exact numbers clearly every time. This means you can read the resolution easily and you can also switch the display to get other readings that are available to you.

2. Superheat and subcooling
Manifold sets with temperature probes can calculate and display real-time superheat and subcooling values, which can allow technicians to see real-time changes to these values. This can be very helpful when those values change rapidly during the troubleshooting process, such as on an outdoor air-cooled condenser with fan cycle controls operating in a cold ambient, or on systems where the TXV is hunting.


3. Refrigerant types
Most analog gauges are ideal for a specific refrigerant. That means that you may have to carry different gauges to be prepared to handle any refrigerant you might encounter out there. The gauges can also be used in other processes such as evacuation and leak testing. Digital manifolds are able to operate with virtually all kinds of refrigerants in the market today.

4. Data Recording
Some digital manifold gauges have a data logging function, which can be useful when troubleshooting unique problems. This can allow technicians to trend the operating pressures or a superheat/subcooling value over time to see when the problem occurs. Some also have a built-in micron gauge, which can helpful during the evacuation process.

5. APP Monitoring
There are also digital gauges that are Bluetooth enabled, which allow technicians to read the displayed value on a smartphone or tablet. This can be helpful when trying to analyze a problem while looking at two different sections of a system. Apps are also available that will help technicians troubleshoot a system problem with suggested issues based on the measured pressures and temperatures.

The drawback to a digital manifold set is that it is much more expensive than a traditional mechanical set, which could be a major consideration when purchasing. They also require batteries, which can be a pain to change or recharge when in the middle of a repair, and they can be difficult to read in direct sunlight.

With the increasing digitalisation of instruments, more and more users are considering whether to switch from analogue to digital. As for whether you should buy a set or not, first look at what you need to finish your job better, and what works for you.