What You'll Learn

• Which equipment types measureQuick supports and how the app classifies them
• Which Guided Workflow to select for each equipment type
• How profile settings differ between split systems, package units, heat pumps, and gas furnaces
• How probe setup changes by equipment type
• How ductless/mini-split systems differ from ducted equipment in measureQuick
• How variable speed and inverter-driven systems require special handling before testing
• How to use the comparison table to quickly match your job to the correct workflow

What You'll Need

• Device: iPhone (iOS 15+) or Android phone/tablet (Android 10+) with measureQuick v3.5+
• Account: A measureQuick account (Guided Workflows and Vitals scoring require an active subscription; see for plan details)
• Knowledge: Familiarity with the AI System Profiler (see AI System Profiler) and basic workflow navigation (see Workflow UI Navigation)
• Time: 10-15 minutes to read

How Equipment Type Affects Your Workflow

Selecting the correct equipment type is the first decision that shapes your entire test. It determines which Guided Workflow the app presents, which measurement fields appear, what diagnostic targets the app calculates, and how many probes you need for a scored Vitals result.

Get it wrong and the app applies the wrong targets. Superheat and subcooling calculations assume the wrong refrigerant cycle direction. Static pressure fields may appear when they should not, or disappear when you need them. The Vitals score becomes unreliable.

As Jim Bergmann explains: "refrigerant and this is really what I consider the most basic of profiles - all right, let's talk about what a profile is first." The profile tells the app what equipment you are working on, and every subsequent calculation flows from that selection.

measureQuick organizes equipment into six primary types. Each maps to one or more Guided Workflows.

Split System A/C

The most common residential equipment type. A split system has two components: an outdoor condensing unit and an indoor air handler or furnace with an evaporator coil.

Workflow Selection

Profile Settings

• System type: A/C (not heat pump, even if the outdoor unit looks similar)
• Refrigerant: Match the nameplate. R410A is the most common (152K tests in the mQ database). R22 systems are still in service (19K tests). New installations may use R454B or R32 (A2L refrigerants).
• Metering device: TXV or fixed orifice (piston). This changes diagnostic targets significantly. As Jim Bergmann notes: "I set the type of metering device - thermostatic expansion valve, piston, capillary tube, the electronic expansion valve, or automatic expansion valve." See Metering Device Selection.
• Tonnage: From the nameplate or AI Profiler result. Verify this value; default of 1 ton invalidates capacity calculations. As shown in the "Setting Up measureQuick Jobsite and Equipment For The First Time" video: "here's where you'll take some pictures of the system, the nameplate data, and enter that in." Photographing the nameplate before profiling avoids trips back to the equipment to re-read faded labels.

Probe Setup

Full diagnostic testing requires 9+ physical probe channels for a scored Vitals result:

• Suction line temperature
• Liquid line temperature
• Discharge line temperature (recommended)
• Outdoor ambient temperature
• Supply air temperature
• Return air temperature
• High-side pressure
• Low-side pressure
• Static pressure (supply and return)

Psychrometer (wet bulb) and electrical measurements (amps, volts, watts) add diagnostic depth but are not required for the minimum Vitals threshold.

What the App Calculates

Superheat, subcooling, CTOA/DTD, saturation temperatures, delivered capacity, EER, TESP, airflow (if TrueFlow or manual entry), and Vitals score.

Package Unit

All components in a single outdoor cabinet. The condenser coil, evaporator coil, air handler, and often a gas heat section are housed together. Common on commercial rooftops and some residential slabs.

Workflow Selection

Package units have dedicated workflows. Do not use the split system A/C workflows; probe placement instructions and measurement phases differ.

Profile Settings

• System type: Package Unit
• Refrigerant, metering device, tonnage: Same process as split systems. Match the nameplate.
• Heat source: If the package unit includes gas heat, note this in the profile. Some package units are cooling-only; others are dual-fuel.

Probe Setup

The same 9+ physical probe channels apply, but placement differs because all refrigerant lines are inside the cabinet:

• Suction and liquid line probes attach inside the unit, not on separate indoor/outdoor line sets
• Supply and return air probes go at the duct connections leaving and entering the unit
• Static pressure taps are at the supply and return duct connections, not at an indoor air handler

Access can be more restricted. Plan probe placement before powering the unit on.

Key Differences from Split Systems

• No long refrigerant line set means less opportunity for line temperature drop
• All refrigerant-side measurements happen in one location
• Static pressure reflects only the duct system, not the indoor unit's internal pressure drop
• Electrical measurements are captured at the single disconnect

Package Unit system profile with single-cabinet equipment fields

Heat Pump (Cooling Mode)

A heat pump in cooling mode operates on the same refrigerant cycle as a split system A/C. The reversing valve directs refrigerant flow in the cooling direction. From a diagnostic standpoint, the measurements and targets are nearly identical to a standard A/C.

Workflow Selection

Heat pumps in cooling mode use the same workflows as split system A/C. The app handles the heat pump distinction through the system profile, not the workflow selection.

Profile Settings

• System type: Heat Pump (not A/C). This matters because the app stores the equipment classification for reporting, and it determines which mode options are available later.
• Refrigerant: Same selection process. R410A dominates. R454B and R32 are entering the market as A2L replacements.
• Metering device: Heat pumps typically use TXV on both the indoor and outdoor coils. Some older units use a fixed orifice on one side.

Probe Setup

Identical to split system A/C. 9+ physical probe channels. Same placement locations.

Key Differences from A/C

• The reversing valve is energized or de-energized depending on manufacturer (some energize in cooling, others in heating). This does not affect your measurements.
• Heat pump market share reached 47.0% of all tests in full-year 2025. You will encounter them frequently.

[Visual Reference] The Heat Pump cooling mode workflow shows the system type set to "Heat Pump" with cooling-mode diagnostic targets. Subcooling and superheat targets match standard A/C values since the refrigerant cycle operates the same way in cooling mode.

Heat Pump (Heating Mode)

When the heat pump reverses to heating mode, the refrigerant cycle direction flips. The outdoor coil becomes the evaporator, and the indoor coil becomes the condenser. Superheat and subcooling measurement locations reverse.

Workflow Selection

This is the only equipment scenario that requires a dedicated workflow. You cannot test a heat pump in heating mode using the A/C or cooling workflows; the diagnostic targets would be inverted.

Profile Settings

• System type: Heat Pump
• Mode: Heating. The app switches diagnostic targets when you select this mode.
• Supplemental heat: Note whether the system has electric strip heat or a gas furnace as backup. This affects the temperature rise the app expects at the supply register.

Probe Setup

The physical probes are the same instruments, but the measurement context changes:

• Suction line is now the line leaving the outdoor coil (which is now the evaporator). In cooling mode this line carries liquid; in heating mode it carries low-pressure vapor.
• Liquid line is now the line leaving the indoor coil (which is now the condenser). In cooling mode this carries subcooled liquid from the outdoor condenser.
• Discharge line remains at the compressor outlet.
• Supply air temperature should be warmer than return air (reversed from cooling mode).
• Outdoor ambient temperature drives defrost cycle behavior and affects expected targets.

If you are unsure which line is true suction in heating mode, use a temperature clamp: the suction line will be cold (close to outdoor ambient or below), and the liquid line will be warm.

9+ physical probe channels are still required for a scored Vitals result.

Key Differences from Cooling Mode

• Superheat is measured at the outdoor coil (the evaporator in heating mode), not the indoor coil
• Subcooling is measured at the indoor coil (the condenser in heating mode), not the outdoor coil
• The app recalculates all diagnostic targets based on the reversed cycle
• Outdoor temperatures below 40F may trigger defrost cycles that interrupt testing; wait for the defrost to complete and the system to restabilize

Heat Pump Heating workflow showing reversed measurement context with outdoor coil as evaporator

Gas Furnace

Gas furnaces are combustion appliances. The diagnostic focus shifts from refrigerant cycle analysis to combustion safety and efficiency. As demonstrated in the measureQuick gas furnace workflow video: "the first thing we want to start off with is obviously the profile, and this has been profiled before, but let's take and review it, and all the data comes off the furnace label ... this is a 60,000 BTU input, 42 on the low side, the temperature split is 15 to 45 degrees ... the maximum gas supply pressure is seven, the minimum is 5 and 3.5." For gas furnaces, the nameplate is the primary source for input BTU, temperature rise range, and gas supply pressure limits.

Workflow Selection

There is one workflow for both installation and service of gas furnaces.

Profile Settings

• System type: Gas Furnace
• Fuel type: Natural gas or propane. This affects expected manifold pressure and BTU calculations.
• Stages: Single-stage, two-stage, or modulating. Modulating furnaces require testing at the high-fire setting for consistent results.
• Tonnage: Not applicable for furnace-only testing. If the furnace is paired with an A/C or heat pump, tonnage applies to the cooling system and would be profiled separately.

Probe Setup

Gas furnace Vitals scoring requires 7+ physical probe channels (not 9+). The measurement set differs from cooling tests:

• Supply air temperature
• Return air temperature
• Static pressure (supply and return)
• Flue/stack temperature
• CO (carbon monoxide) concentration
• O2 (oxygen) concentration
• Draft pressure
• Manifold gas pressure (optional but recommended)

A combustion analyzer (Sauermann is the currently supported option) provides CO, O2, stack temperature, and draft. Temperature probes handle supply, return, and ambient.

Key Differences from Cooling Systems

• No refrigerant pressures, no superheat/subcooling, no condenser or evaporator measurements
• Combustion safety is the primary diagnostic concern: CO levels, draft, and combustion efficiency
• Temperature rise (supply minus return) replaces DTD/CTOA as the key temperature metric
• The expected temperature rise range comes from the furnace nameplate (typically 30-70F depending on the model)
• The app presents combustion-specific diagnostic flags and pass/fail indicators instead of refrigerant-based ones

Gas Furnace workflow showing combustion measurement fields including CO, O2, stack temperature, and draft

Ductless / Mini-Split Systems

Ductless and mini-split systems use the same refrigerant cycle as ducted split systems, but they deliver conditioned air directly to the space without ductwork.

Workflow Selection

The mini-split workflow is currently in beta. If it is not available on your app version, use the A/C or Heat Pump Service workflow and adjust your expectations for which fields will have data.

Profile Settings

• System type: Mini-Split or Ductless (select the option available in your app version)
• Refrigerant: R410A is most common. Some newer units use R32.
• Metering device: Most ductless systems use electronic expansion valves (EEV), which behave differently from TXV or fixed orifice. Select the closest match available in the profile.
• Tonnage: Often expressed in BTU (9,000 BTU = 0.75 ton, 12,000 BTU = 1 ton, 18,000 BTU = 1.5 ton, etc.)

Probe Setup

Refrigerant-side probes apply the same way: suction line, liquid line, and high/low-side pressures. The differences are on the air side:

• No static pressure measurement. There is no duct system to create static pressure drop. The manometer fields will be empty or irrelevant.
• No TrueFlow airflow measurement. TrueFlow requires a filter slot in a ducted system. Airflow for ductless units can be measured with a capture hood (CPS EasyHood or Testo 420) at the wall unit's discharge, but this is not part of the standard workflow.
• Supply and return air are measured at the indoor wall unit's outlet and inlet, not at duct registers.

Key Differences from Ducted Systems

• Static pressure diagnostics are not applicable
• Airflow diagnostics are limited; the pass/fail assessment for ductwork-related subsystems does not apply
• Multi-zone systems (one outdoor unit serving multiple indoor heads) require profiling each indoor unit separately
• Line sets can be significantly longer than ducted systems (up to 75-100 feet on some installations), which affects subcooling expectations

Variable Speed / Inverter-Driven Systems

Variable speed systems use inverter-driven compressors that modulate capacity instead of cycling on and off. They run at the speed needed to match the load, which means they rarely operate at full rated capacity during normal conditions.

This creates a measurement problem. If you test a variable speed system while it is running at 40% capacity, your superheat, subcooling, and efficiency numbers will not match the rated design targets. The diagnostics will be inaccurate.

Workflow Selection

Use the same workflows as the equivalent fixed-speed system:

The workflow is the same. What changes is the pre-test preparation.

Profile Settings

• System type: A/C or Heat Pump (same as fixed speed)
• SEER rating: Variable speed systems are typically SEER 20+. Enter the rated SEER from the nameplate.
• Metering device: Most variable speed systems use EEV. Select the closest available option.
• Capacity: Enter the full rated capacity (design tonnage), not the current operating capacity.

Critical: Put the System into Test Mode

Before taking measurements, you must force the system to run at full design capacity. The procedure varies by manufacturer:

• Some systems have a "test mode" or "forced cooling" function accessible through the thermostat or control board
• Some require a specific thermostat setpoint differential (set the thermostat 10-15F below room temperature to force maximum output)
• Some require a technician service tool or manufacturer-specific app

Consult the manufacturer's installation manual for the test mode procedure. If you cannot force full capacity, your measurements will not match design targets and the Vitals score will be unreliable.

Probe Setup

Same as the equivalent fixed-speed system type. 9+ physical probe channels for cooling/heating. No additional probes are required.

Key Differences from Fixed-Speed Systems

• You must confirm the system is running at design capacity before capturing measurements
• Allow extra stabilization time; variable speed compressors may take longer to reach steady state
• If the system will not hold full capacity (common in mild weather when the load is low), document the operating capacity percentage if known
• Some variable speed systems display operating frequency or capacity percentage on the thermostat or control board; note this in the project for reference

Equipment Type Comparison Table

Video Walkthrough

• (9,324 views, 18:40) - Detailed walkthrough of profiling and testing variable speed/inverter-driven systems, including test mode procedures

• (975 views, 1:12) - Shows AI-based equipment identification for supported system types

• (1,714 views, 1:57) - AI Profiler demonstration on various equipment types

• Full gas furnace workflow walkthrough covering profile setup from the furnace label, combustion analyzer connection, static pressure measurement, and CO monitoring at supply and return

• First-time equipment setup covering nameplate photo capture, system profiling, and probe deployment

• New system commissioning walkthrough including profile setup with tonnage selection and model number entry

• Heat pump heating mode guided workflow covering reversed probe deployment and TXV diagnostics

Tips & Common Issues

I selected A/C but the system is actually a heat pump

If the outdoor unit has a reversing valve, it is a heat pump. Change the system type in the profile to Heat Pump. In cooling mode the diagnostic targets are nearly identical, but the equipment classification affects reporting and determines whether heating mode workflows are available later. You can change the system type in the profile without restarting the workflow.

The app is not showing combustion fields

You are in a cooling or heat pump workflow. Combustion measurements (CO, O2, draft, stack temperature) only appear in the Gas Furnace workflow. If you need to test a dual-fuel system, run the cooling test first, save it, then start a separate Gas Furnace workflow for the furnace diagnostics.

My variable speed system will not hold full capacity

In mild weather (outdoor temperature between 65-80F), some inverter systems will not ramp to full capacity because the load is too low. Options:

• Use the manufacturer's test mode or forced cooling function
• Set the thermostat to the maximum differential the system allows
• If you still cannot achieve full capacity, document the operating condition and note the partial capacity in the project. The Vitals score may not be accurate.

The mini-split workflow is not available in my app version

Use the A/C or Heat Pump Service workflow. Skip or leave blank the static pressure and airflow fields. The refrigerant-side diagnostics will work correctly. The Vitals score may be incomplete without airflow data.

How do I test a dual-fuel system (heat pump + gas furnace)?

Run two separate tests. Test the heat pump using the appropriate heat pump workflow (cooling or heating, depending on the season and mode). Test the gas furnace using the Gas Furnace workflow. Save each as its own test record in the same project.

Which refrigerant should I select for new A2L systems?

R454B and R32 are both available in the refrigerant selection list. Select the one that matches the nameplate. These are mildly flammable (A2L classification) refrigerants replacing R410A. The diagnostic targets differ from R410A, and the app applies the correct saturation properties for each refrigerant automatically.

Related Articles

Prerequisites (you may need these first):

• AI System Profiler
• Workflow UI Navigation

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

• Metering Device Selection
• Variable Speed Equipment (detailed profiling)
• A/C Installation Workflow
• Gas Furnace Workflow
• Heat Pump Heating Mode Probes

Related in the same domain:

• Manual System Profile
• Profile Verification
• High-Efficiency Systems

Need Help?

Contact measureQuick support: support@measurequick.com