Author: clidzbarski@fieldpiece.com

The HVACR industry has witnessed significant technological advancements in measurement and diagnostic tools over the years. From the era of analog refrigerant manifold gauges to modern digital gauges and wireless probes, the tools available to HVACR technicians have evolved to enhance accuracy, efficiency and convenience. Understanding the differences and strengths between these tools is crucial for technicians aiming to optimize their performance and service quality.

Analog Refrigerant Manifold Gauges

For decades, analog refrigerant manifold gauges were the standard in the HVACR industry. These tools allow for the addition and removal of refrigerant and measure system pressures while displaying saturation temperatures manually. They offer reliable and actionable data but require the use of additional instruments for anything outside of pressure and saturation temperature.

Analog gauges are often a great starting point for new technicians given their simplicity and lower price point. But they are far from “entry-level only” tools. Many experienced technicians keep an analog manifold in their truck alongside their digital tools because of their durability and reliability in tough environments.

One significant drawback of traditional analog gauges is the potential for inaccuracies due to human error and the inherent limitations of manual calculations. For instance, calculating superheat and subcooling with analog gauges involves multiple steps, including using a separate thermocouple for temperature readings and manual calculations based on pressure-temperature charts. This process is not only time-consuming but also prone to errors.

However, many technicians appreciate analog gauges for:

• Their robustness and reliability in demanding environments
• Situations where they prefer not to risk damaging higher-priced digital equipment
• Quick pressure checks and basic charging tasks
• Training environments where learning system fundamentals are key

It’s also common for techs to own both digital and analog manifolds and choose between them depending on the job. Analog gauges remain a dependable, cost-effective solution that delivers solid performance when used correctly – especially when built with durability and reliability in mind, like the new Fieldpiece analog gauge sets.

Digital Refrigerant Manifold Gauges

The introduction of digital refrigerant manifold gauges revolutionized the HVACR industry. Digital manifolds, such as the Fieldpiece SMAN® Series, offer several advantages over their analog counterparts:

• Higher Accuracy and Resolution: Digital gauges provide more accurate readings, reducing the risk of human error.
• Automated Calculations: Digital manifolds automatically calculate critical values like superheat and subcooling, streamlining the diagnostic process.
• Convenience: These tools display readings directly on their screens, and some allow for the wireless connection of additional tools such as psychrometers.
• Durability: Digital manifolds are designed to withstand field conditions while maintaining calibration and performance.

Digital manifolds have simplified the workflow for HVACR technicians, allowing them to take accurate measurements and adjust refrigerant levels quickly and efficiently.

Wireless Probes

Wireless probes represent the latest advancement in HVACR diagnostic tools. These compact instruments allow a technician to remotely take readings both inside and outside a home, with some allowing for data aggregation and calculation on smart devices. Wireless ranges for these devices can vary, with some reaching up to 1000 ft for access to live measurements on large job sites. For example, usage of wireless psychrometer probes to measure Delta T eliminates the need for a technician to repeatedly walk inside and outside to take readings.

The compact size of most probes also makes optimal placement in tight spaces or cramped service ports easier, which is crucial for achieving accurate readings. One of the few drawbacks to a wireless probe kit would be that adding or removing refrigerant will still require an additional tool in your configuration, such as a T-fitting or a valve core removal tool. However, system checks and quick diagnostics are more than possible with a well-rounded probe kit.

The Fieldpiece JL3KH6 Charge and Air Kit is one example, featuring Wireless Pipe Clamps, Pressure Probes, and Flexible Psychrometers. A comprehensive probe kit can be a technician’s best resource for conducting fast and efficient system diagnostics, making it an industry staple.

Choosing the Right Tool

When deciding between analog gauges, digital manifolds and wireless probes, HVACR technicians should consider their specific needs, workflow and jobsite conditions.

• Analog gauges provide rugged simplicity and dependable performance, especially with modern builds like Fieldpiece’s new Analog Gauge Sets. They’re ideal for technicians who want durability, cost-effectiveness, and a straightforward charging tool.
• Digital manifolds offer higher accuracy, automated calculations, and expanded functionality. Tools like the Fieldpiece SMAN® series allow wireless connectivity and advanced diagnostics.
• Wireless probes like the Job Link® System Charge & Air Kit, provide maximum flexibility and mobility, allowing for real-time monitoring via mobile devices and streamlined system checks.

Wireless probes are ideal for technicians who value precision and efficiency on jobs that require a quick snapshot of system readings. However, if using a mobile device is not feasible due to environmental conditions or personal preference, digital and analog manifolds remain robust alternatives.

In conclusion, the choice between analog, digital and wireless tools depends on the technician’s workflow and the specific requirements of the job. Embracing modern technologies like digital manifolds and wireless probes can significantly enhance diagnostic accuracy and service efficiency. At the same time, sticking with fundamental tools like rugged analog gauges – especially modernized versions built for today’s demands – ensures technicians always have a dependable back up option in the truck.

 

Temperature is everything

The key to understanding HVAC system performance is… to take its temperature! The supply and return temperatures, or Delta T, offer a technician crucial details about heat transfer at the evaporator coil, performance of the heat exchanger, refrigerant charge, and the effectiveness of air flow within the conditioned space.

Know exactly where to take the temp

Assessing system performance starts with measuring the supply side and return side temperatures. First, locate the supply air duct close to the air handler or the furnace. This is an optimal place to measure. If necessary, drill an access hole a few feet downstream of the heat exchanger or the evaporator coil for accurate readings.

To measure the return air temperature, measure in the duct closest to the furnace, drilling an access hole in the ductwork, if necessary. This measures the air returning to the HVAC system from the conditioned spaces. Ensure consistency by measuring at the same location each time.

Best practices for accurately finding temperatures

When taking readings, always stabilize the system first by running it for 15-20 minutes. Then, ensure the temperature probe is not affected by drafts or nearby heat sources such as heat strips found in heat pumps. When inserting the probe through an access hole, be sure that it’s placed in the airflow, and not touching the duct walls. Once finished, seal the access point to avoid air leaks.

Make sure the probe is inserted in the duct and not influenced by the room air. Consider taking readings at multiple supply vents to check for uniformity as well. If there are large discrepancies in readings at different locations, the system could have ductwork or airflow issues.

Benefits of Measuring Out of Duct

Delta T is most accurately measured in the duct, but prior to drilling, technicians can get a quick estimate by measuring temperatures at the nearest return vent and supply register or grill. Additionally, taking measurements at the end of the return and supply can assist a technician in diagnosing temperature loss or gain due to duct leaks.

Tools designed for the job

Fieldpiece makes many wireless, handheld tools designed specifically for quick temp checks. When measuring temperature in a duct, or at a register or grill, here are a few of our favorites:

• PRH2 Digital Psychrometer – Use this versatile, pocket-sized psychrometer to measure wet bulb, %RH, dew point and dry bulb temperatures. Readings are shown on the backlit, dual display and the tool can measure temps in the duct or while walking around.

• SPK1 Pocket Knife-Style Thermometer –This digital thermometer opens just like a pocketknife and features a sharp tip for piercing through flex ducts. It hangs easily at any angle from a vent or thermostat.

• SPK2 Folding Pocket In-Duct Thermometer – Also great for taking quick air temperatures, this folding thermometer rod can punch through flex ducts and easily hangs from a duct or on a grille. Not in the mood for math? The SPK2 holds measurements and calculates the delta T for you.

• SPK3 Rod and IR Temperature Pocket-Style Tool – In addition to a duct-piercing thermometer rod and delta T calculator, the SPK3 includes an IR feature with an 8:1 field of view angle and laser guide. The perfect tool to use when you’re doing a walk-around check of air temps at registers in hard-to-reach locations.

• SIG1 Gun-Style IR Thermometer – This standalone, non-contact infrared thermometer features a 10:1 field of view, a bright blue backlight, and a laser guide for fast, accurate readings.

Thank you for coming to our Temp Talk

As an HVAC pro, listen to your system’s air temps – they’ll tell you a lot about system performance. If you want to measure these temperatures quickly and precisely every time, pick up some of these powerful pocket tools from Fieldpiece.

A vacuum pump is a powerhouse machine that removes air, gases, moisture, and contaminants from a system to create a clean environment for refrigerant. These efficient and powerful machines need clean oil to perform at their peak. When oil becomes cloudy or saturated, the pump won’t work as well, and pulling a deep vacuum takes longer.

Double-duty Oil

The oil in the vacuum pump acts as both a lubricant and as a sealant. It keeps the pump vanes (rotor blades) lubricated and helps keep a proper seal for an optimal vacuum. The deep vacuum that the pump creates helps push moisture and non-condensables from the system to the pump, ensuring the system is ready for refrigerant. This process contaminates the oil in your vacuum pump, which negatively impacts the pump’s performance and efficiency by compromising its internal seal. Pumps with contaminated oil will struggle to create a strong pressure differential, leading to increased evacuation time and eventual damage to the pump.

When to Change the Oil

The need to change your oil will depend on several factors. The most effective way to maximize performance and efficiency of your vacuum pump is to change the oil after each evacuation. In humid environments systems are more likely to contain moisture. Systems with more moisture and non-condensable contaminants present will contaminate your oil faster, requiring more frequent changes to maintain performance. Moisture contamination is easy to spot because the oil looks milky or cloudy. Other contaminants can sink to the bottom of your oil reservoir, so vacuum pumps with better reservoir visibility, such as the large window on the Fieldpiece vacuum pumps, allow for more accurate monitoring.

Another key indicator that it’s time for an oil change is pump efficiency. When pulling a vacuum, if the rate at which your microns are decreasing starts to level out, this could signal the need to change oil. When pump efficiency starts to wane, pulling a deep vacuum becomes more time-consuming. Note that the time to pull a vacuum will vary depending on the size of the system, atmospheric conditions such as humidity, and the efficiency of your evacuation setup.

Oil Changes on the Fly

Some pumps on the market allow the oil in the pump to be changed while it’s pulling a vacuum, like the RunQuick® oil change system on Fieldpiece vacuum pumps. Towards the end of the evacuation is when you need fresh oil the most, so oil changes on the fly are key to working faster and smarter.

Get a Vacuum Pump that Works for You

Since clean, dry oil is crucial for faster evacuations, consider vacuum pumps that make oil changes quick and hassle-free. Fieldpiece vacuum pumps are powerful, portable and offer oil changes on the fly, saving you time on every evacuation. See the entire line of pumps, oil and other HVAC tools built and designed for techs.

For refrigerant heating and cooling systems to work correctly and optimally, the refrigerant must be free of air, nitrogen, moisture, and contaminants. Therefore, before charging a system, it’s critical to evacuate the system with a vacuum pump to create a clean and sealed environment. Here are a few tips and best practices to make your next evacuation faster and more effective. 

 

Tip 1: Purge with Nitrogen 

Moisture in a system can drastically increase the time it takes to pull a vacuum and removing that moisture and other contaminants is a crucial step to saving time. To ensure that the system is free of excess oxygen, refrigerant, moisture, and other contaminants, purge it with nitrogen. This is different than flowing nitrogen or conducting a nitrogen pressure test. To purge, connect a nitrogen tank and flow nitrogen through the system at around 100 PSI. This allows nitrogen to flow into one side and then out the other. The movement displaces excess oxygen and air. It also removes any dangerous gases and ensures the system is dry. While performing this purge, be sure to keep the area well-ventilated. Nitrogen can displace oxygen and create a dangerous environment for techs or other occupants, so always keep this in mind. 

 

Tip 2: Triple Evacuate 

When working in humid environments or on systems with significantly more moisture, a triple evacuation is a great way to remove the moisture entirely. This is an industry requirement for some OEMs, and one of the most effective techniques for systems with high moisture content. Start by sealing the system off and pulling the system down to a vacuum of between 1000 and 2000 microns. Then, break the vacuum by introducing nitrogen for 5 minutes at 5 PSIG. Perform another evacuation to 500 microns, and then break it again with nitrogen for five minutes. Perform a third evacuation and pull the system down to between 200 and 300 microns. Let the system sit for 10 minutes, or longer for larger systems. Performing the triple evacuation purges with nitrogen helps the excess moisture and other contaminants vent out of the system. Not to mention, systems with less moisture allow for pulling a vacuum faster, saving you time on the job. 

 

Tip 3: Change Your Oil 

Within a system is not the only place where moisture can impede evacuation efficiency. High moisture content in your vacuum pump oil considerably reduces your pump’s ability to pull a deep vacuum quickly. Cloudy oil is a sign of moisture buildup, a natural occurrence in used oil. Vacuum pumps with clean, dry oil can maintain a higher pressure differential, speeding up the vacuum process and allowing for a deeper vacuum. This means more frequent oil changes directly improve your ability to evacuate systems quickly, once again saving you time on the job. With Fieldpiece vacuum pumps featuring the RunQuick® oil change system, you can change oil in seconds without losing vacuum.  

Effective tools are only part of an effective service. Staying informed and up to date on best practice is just as important, so we hope these tips help make your system evacuations easier, faster, and better!