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Digital vs. Analog Gauges

Digital vs. Analog Gauges

Digital vs. Analog Gauges

Are digital gauges necessary? This is a question that comes up a lot, and there are a wide variety of opinions. After all, the HVAC industry doesn’t seem to favor one style over the other. Why is one any better than its alternative?

Most HVAC technicians should keep at least two sets of gauges, and potentially three depending on their exact work. Different types of HVAC units may be more compatible with different gauges. Consequently, there isn’t really a clear answer to the question of which gauge type is superior, if at all. Let’s take a closer look at both types and their potential applications to find the right answer for your situation.

HVAC technicians may use both digital and analog gauges in their daily work. Which type is better for standard usage? Find out here. Click To Tweet

Different Types for Different Work

You need two, possibly three, sets of gauges depending on what you are doing. Some techs like to have one set for 410 refrigerant machines and another for R22 machines. However, we have so many different types of refrigerants now it’s not practical to have a set of gauges for each. One set of digital gauges and one back up set of analog gauges is all most people will ever need.

Using Digital vs. Analog Gauges

Digital gauges are far superior for testing and adjusting the charge, and they’re absolutely imperative if you want accurate superheat and subcooling readings. Digital gauges have temperature clamps that connect to the liquid line and suction line and have built-in pressure-temperature charts. You simply tell the gauge set what refrigerant you are testing, hook up the hoses and temp clamps, and get live instant readings of superheat and subcooling. The margin of error is remarkably low.

If you use analog gauges to perform critical charging, you will have to read literally between the lines of the needle and the gauge lines. Once you guess the pressure reading, you must then use a pt chart to obtain the temperature equivalent. After you get that number, you have to actually take a temp reading of the appropriate line and subtract those two numbers. Along the way, chances are you will either misread something, make a mistake in the math, make a pt chart conversion mistake, or several of the above. Even if you manage to get all that correct, there’s a good chance that the system pressure or temperature changed between all the readings. This change alone will lead to inaccuracies of four to five degrees. When you are talking about subcooling number targets of 10 or 12 degrees and you miss it by six, that’s a significant margin of error.

What Do Industry Professionals Prefer?

Some brand manufacturers require the dealers to charge with digital gauges if they want to continue and sell that brand. Usually, these policies exist because manufacturers have received warranty returns due to improper charging methods rather than actual problems. Consequently, the requirement for digital gauges is a (generally successful) attempt to combat these warranty returns and preserve business.

Analog gauges have their place, however, especially if you are working on a system that has a bad burn out and has turned the oil into acid. You will not want to pull this into your $400 digital gauge set, so you whip out the trusty analog set. The analog is also a great back-up set when your digital set goes out. 

Pro Tip: Different brands of digital gauges may have varying features, but overall, they all work about the same. Just find the brand with features you like the most.

Neither is Always Better

To summarize, there is no way to state for certain which type of gauge is better. While digital gauges are more convenient and generally preferred by HVAC professionals and manufacturers, sometimes an old-fashioned analog gauge works just as well or even better. The ultimate deciding factor is preference. To make sure you always have the type you or a client prefer, maintain a set of each type of gauge just in case.

Join the conversation to learn more about the best HVAC equipment for your situation and preferences.

R22: Is it Really the King of Refrigerants?

R22: Is it Really the King of Refrigerants?

The vast majority of American homes with HVAC systems use R22 refrigerant in the coolant system. Historically, this coolant has been regarded as the most effective and the best overall value, contributing to its widespread use. Plenty of HVAC technicians still highly praise this refrigerant and use it in all their work. However, is R22 really everything it’s claimed to be?

A growing number of HVAC technicians and industry experts are beginning to turn to alternatives to the R22 refrigerant. Whether they cite environmental concerns, chemical differences, or any of a number of other reasons, it’s worth looking closer at their questions about this so-called king of refrigerants.

R22 coolant may not deserve all the praise it gets from the HVAC industry. Take a closer look and learn the facts about this chemical here. Click To Tweet

Environmental Concerns

Almost since the invention of home air conditioning, R22 has been the nearly-exclusive refrigerant most people used. If not for its environmental dangers, it would probably still hold that title. The ingredients in R22 are known to damage the ozone layer and contribute to greenhouse gases. Even after the problem was discovered and a solution agreed upon, the deadline for a resolution has only recently begun to loom and prompt quick action.

Alternatives to R22

The puron refrigerant R410A, which was significantly safer for the environment, slowly began to gain prominence with time. Reluctant technicians stayed away from R410A at first, citing a host of reasons it didn’t work. Others pointed out that because of their different chemical compositions, R410A produced higher pressure than R22, making the compressors work harder in an HVAC system. R410A also contains caustic POE oils instead of the much safer mineral oil used in R22.

As the deadline approached, many manufacturers had to stop producing machines designed to use R22. Consequently, more and more technicians sought out alternatives such as R410A. However, many continued to cite bad results and blamed the new refrigerant rather than a lack of effort to change. Many still tried to purchase R22 for their work, causing the price to skyrocket from $50/jug to more than $900.

What This Means for Your HVAC Career

Chemists had developed a host of alternatives that could be used in R22 units, including several refrigerants with a near-perfect match on performance and pressure. Today, there are at least 10 refrigerants available that either match or outperform R22 in its refrigerant properties.421A in particular shows great promise. Why spend hundreds of dollars on an environmentally unsafe compound when you can save money and the earth through buying an alternative refrigerant?

Of course, many of your clients will still have older machines that use the original types of refrigerants or an alternative to R22 that you may not have heard of. Before you buy any new refrigerant for a client or suggest a top-off of what they have, make sure you know exactly what type they’re currently using. Putting in the wrong compound could damage their HVAC unit and cause terrible warranty problems for you as the contractor.

Pro Tip: Different units will use different types of refrigerants. Make sure to educate yourself on the most common types and their pros and cons so you can help your customers make an informed decision.

Finding the Right Refrigerant for the Job

The modern world changes rapidly, and the HVAC industry is no exception. Refrigerants will come and go as more cost-effective and environmentally friendly options are developed. Always be willing to compare your old favorites to new products. You may be surprised to see that what was once the gold standard now takes a backseat to a new arrival, much like the R22 refrigerant is phasing out of the industry.

Connect with us to learn more about different HVAC refrigerants and how to best use (or avoid) them in your career.