What You'll Learn

• What Quick Charge Mode is and how it differs from the full diagnostic workflow
• Which measurements Quick Charge displays and which it hides
• When to use Quick Charge: topping off charge, adding refrigerant to a known-good system
• When not to use Quick Charge: initial commissioning, unknown system condition, complex faults
• How to run Quick Charge in measureQuick v3.5

What You'll Need

• Device: iPhone (iOS 15+) or Android phone (Android 10+) with measureQuick v3.5+
• Account: Basic tier or higher
• Tools: Pressure gauges (manifold or wireless probes), suction and liquid line temperature clamps, outdoor ambient temperature probe. Refrigerant scale and tank for the refrigerant type being charged.
• Knowledge: Understanding of superheat and subcooling targets for the system's metering device type (see E3). Familiarity with the AC Service Workflow (see G2).
• Time: 5 minutes to read; 10-20 minutes for a Quick Charge session in the field

What Is Quick Charge Mode?

Quick Charge Mode is a focused refrigerant charging workflow available in measureQuick's Quick Tests menu. It strips away the full diagnostic interface and shows only the measurements relevant to adding refrigerant: superheat, subcooling, suction pressure, discharge/liquid pressure, suction line temperature, liquid line temperature, and outdoor ambient temperature.

The purpose is speed and clarity. When you already know the system is mechanically sound and you just need to verify or adjust the charge, the full diagnostic screen with 20+ measurement points adds complexity that slows you down. Quick Charge gives you the essentials in a clean, simplified view.

Jim Bergmann notes in the Cooling Commissioning Measurements walkthrough: "You can also do the quick charging mode, which is helpful for newer technicians to actually indicate" the charge state without the visual noise of the full diagnostic screen.

Step-by-Step Guide

Step 1: Confirm Quick Charge Is Appropriate

Quick Charge is the right tool when:

• Adding charge to a system with a known leak repair: You fixed the leak, evacuated the section, and now need to restore the charge. The system was previously diagnosed, and you know the only issue is missing refrigerant.
• Topping off after a component replacement: You replaced a TXV, filter drier, or line set section and need to add refrigerant to compensate for the new component volume.
• Verifying charge on a system you just charged: You weighed in the factory charge and want a quick confirmation that superheat/subcooling targets are met.
• Return visit to adjust charge: A previous technician's notes indicate the charge was close but slightly off, and you need to fine-tune.

Quick Charge is not appropriate when:

• Initial system commissioning: New installations require a full diagnostic with all measurement points to verify total system performance, not just charge.
• Unknown system condition: If you have not performed a diagnostic and do not know whether the system has airflow problems, electrical issues, or other faults, charge readings alone are misleading. Airflow restriction causes the same superheat/subcooling symptoms as incorrect charge.
• System has multiple faults: If the diagnostic flags showed airflow, electrical, and charge failures, address the other issues first. Charging a system with restricted airflow results in an overcharge once the airflow is corrected.
• Customer reports a specific complaint you have not diagnosed: Do not skip straight to charging. Run a full diagnostic first to identify all faults.

Step 2: Access Quick Charge Mode

From the measureQuick home screen:

1. Tap Quick Tests
2. Select Quick Charge Mode
3. The app opens a simplified charging interface

If you have an existing project for this customer, you can also access Quick Charge from within the project. The charge data will be associated with the project for documentation purposes.

Quick Tests menu showing Quick Charge Mode option

Step 3: Profile the System

Enter or confirm the equipment profile:

• Refrigerant type: R410A, R22, R454B, R32, or other. This is critical because saturation tables and target ranges differ by refrigerant.
• Metering device: TXV or piston/fixed orifice. This determines whether you charge by subcooling (TXV) or superheat (piston).
• Tonnage: Affects expected operating pressures and charge quantity.
• Outdoor ambient temperature: The app uses this to calculate target superheat for piston systems.

If you started from the cloud and the system already has a profile, verify the refrigerant type and metering device. An incorrect metering device setting produces wrong charging targets.

Step 4: Connect Probes for Charging

Quick Charge requires a minimal probe set:

Connect your manifold gauges or wireless pressure probes. Place temperature clamps on the suction and liquid lines at the outdoor unit service valves. Place the ambient probe in a shaded area near the outdoor unit.

The app displays live readings as probes connect.

Step 5: Charge and Monitor

With probes connected and the system running, the Quick Charge screen shows:

• Superheat (current value and target range)
• Subcooling (current value and target range)
• Suction pressure
• Discharge/liquid pressure
• Line temperatures

For TXV systems: Charge to the subcooling target. Add refrigerant slowly and watch subcooling rise toward the target range (typically 8-14F for R410A, varies by manufacturer). Superheat should self-regulate through the TXV as subcooling reaches target.

For piston/fixed orifice systems: Charge to the superheat target. The target superheat depends on outdoor ambient temperature and indoor wet-bulb; the app calculates this from the ambient probe reading. Add refrigerant and watch superheat drop toward the calculated target.

Add refrigerant in small increments. Wait 2-3 minutes between additions for the system to equilibrate. Quick Charge shows real-time trends, so you can see the effect of each addition.

Quick Charge live view showing superheat and subcooling gauges with current values approaching target ranges

Tip: Do not rush the charge. Even in Quick Charge mode, the system needs time to stabilize after each addition. Overcharging because you added too much too fast is one of the most common field errors.

Step 6: Verify and Save

When superheat (piston) or subcooling (TXV) reaches the target range:

1. Stop adding refrigerant
2. Wait 3-5 minutes for final stabilization
3. Confirm the values remain within target
4. Save the data

The Quick Charge session is stored with the project. If you need to generate a report, return to the full project view to create the PDF.

Quick Charge vs. Full Diagnostic: What Is Different?

Quick Charge is a focused tool, not a shortcut for full diagnostics. Use it only when a full diagnostic has already been completed or is not needed.

Video Walkthrough

• YouTube: (23 min, 24,378 views) - Comprehensive charging procedures including proper stabilization, metering device identification, and target verification. Applicable to both Quick Charge and full diagnostic charging

• YouTube: (1 min) - Quick overview of charging best practices

• YouTube: - Mentions the Quick Charge mode and its use case for newer technicians

• YouTube: - Covers charging fixed orifice metering devices and how the app displays charge targets

Tips & Common Issues

Superheat or subcooling is not moving toward target after adding refrigerant

Check the basics first: Is the system actually running? Is the outdoor fan operating? Is airflow across both coils unrestricted? If there is an airflow problem (high static pressure, dirty filter, blocked condenser), charge readings will not respond normally to refrigerant additions. Exit Quick Charge and run a full diagnostic to assess the whole system.

I am not sure whether the metering device is TXV or piston

The metering device determines which parameter you charge by. If you charge by subcooling on a piston system (or by superheat on a TXV system), you will likely overcharge or undercharge. Check the indoor coil data plate or the installation manual. If you cannot determine the metering device type, run a full diagnostic where the AI System Profiler can help identify the equipment configuration.

Can I use Quick Charge for R454B or R32 systems?

Yes. measureQuick v3.5 includes saturation tables for R454B and R32. Select the correct refrigerant in the system profile. The targets and calculations adjust automatically. Be aware that R454B is a mildly flammable (A2L) refrigerant, so follow all applicable safety procedures when handling.

Quick Charge says "out of range" but the system seems fine

If the charge appears correct but the app shows out-of-range, verify: (1) the refrigerant type is correct in the profile, (2) the outdoor ambient reading is accurate and the probe is not in direct sunlight, (3) the system has been running long enough to stabilize. An incorrect ambient reading shifts superheat targets significantly on piston systems.

When should I switch from Quick Charge to a full diagnostic?

If the charge does not converge on target after a reasonable amount of refrigerant has been added, or if you notice abnormal pressures that suggest a restriction, non-condensables, or compressor problem, close Quick Charge and run a full diagnostic. Quick Charge assumes the system is otherwise healthy. When it is not, the full diagnostic is necessary to identify what else is wrong.

Related Articles

Prerequisites (complete these first):

• AC Service Workflow - Full Test In / Test Out service procedure
• Superheat & Subcooling in measureQuick - Charging fundamentals

Follow-up articles (next steps after this one):

• Cold Weather Charging - Charging when outdoor temperatures are below 55F
• Generating Reports - Creating customer-facing documentation from Quick Charge data

Related in the same domain:

• Non-Invasive Service Testing (NIT) - Temperature-only assessment when gauges are not connected
• Heat Pump Service Workflow - Full heat pump diagnostics
• System Stabilization - Detailed guidance on when readings are stable enough to evaluate
• AI System Profiler - Equipment identification for accurate profile setup

Need Help?

Contact measureQuick support: support@measurequick.com