What You'll Learn

• How to run an evacuation test using a BluVac vacuum gauge with measureQuick
• How the BluVac app communicates with measureQuick through app-to-app integration
• Target vacuum levels for different refrigerants (500 microns for R410A, R454B, and most modern refrigerants)
• How to perform a proper decay test: isolating the system, monitoring for rising microns, and interpreting results
• What rising microns during a decay test indicates and how to respond
• How measureQuick records evacuation data and includes it in project reports

What You'll Need

• Device: iPhone (iOS 15+) or Android phone (Android 10+) with both measureQuick and BluVac apps installed
• Account: measureQuick account (Quick Tests generate free PDF reports)
• BluVac gauge: BluVac Pro or BluVac Max, charged and connected via Bluetooth to the BluVac app
• Vacuum pump: Appropriately sized for the system (larger pumps for larger systems)
• Core removal tool and hoses: For connecting the vacuum pump to the system
• Micron gauge position: Mounted at the system, not at the pump, for accurate readings
• Time: 15-45 minutes depending on system size and cleanliness

How BluVac Works with measureQuick

The BluVac gauge does not connect directly to the measureQuick HVAC app via Bluetooth. Instead, measureQuick and BluVac use an app-to-app communication scheme. The BluVac app handles the vacuum gauge connection and data collection. measureQuick launches the BluVac app from within a project, and the evacuation results pass back to measureQuick when the test completes.

This design avoids redundancy between the two apps. The BluVac app is purpose-built for evacuation monitoring with features like multi-gauge support, grid view, and detailed decay tracking. measureQuick integrates the results into the broader project record.

To enable the integration: in the measureQuick app, go to Toolbox > Data Sharing Tools > BluVac System Evacuation App and choose Activate. This only needs to be done once.

Step-by-Step Guide

Step 1: Set Up the Vacuum Rig

Before opening measureQuick, prepare the physical setup:

1. Connect your vacuum pump to the system's service valves using appropriately sized hoses. Larger diameter hoses (3/8" or 1/2") reduce evacuation time significantly compared to 1/4" hoses.
2. Use a core removal tool to remove Schrader valve cores from the service ports. The cores create a significant restriction during evacuation.
3. Mount your BluVac gauge at the system, not at the pump. The gauge must read the vacuum level at the point furthest from the pump to get an accurate measurement of the entire system's vacuum level.
4. Open all valves between the pump and the system.

[Visual Reference] Vacuum rig connected to an HVAC system's service valves via large-diameter hoses (3/8" or 1/2"). The BluVac digital vacuum gauge is mounted at the service valve on the system side, not at the pump. Schrader valve cores have been removed from the service ports. This placement ensures the gauge reads the true vacuum level at the furthest point from the pump, giving an accurate reading of the entire system's vacuum state.

Tips:

• Keep hose runs as short as possible
• Check all connections for tightness before starting the pump
• A small leak in your vacuum rig will cause a false failure during the decay test

Step 2: Start the Evacuation in measureQuick

Open your project in measureQuick. Navigate to Quick Tests and select Evacuation Test with BluVac. measureQuick will launch the BluVac app.

In the BluVac app, confirm your gauge is connected and reading. Start the vacuum pump. The BluVac app displays the current vacuum level in microns in real time as the pump pulls the system down.

[Visual Reference] BluVac app screen during active pump-down. The display shows the current vacuum level in microns, decreasing in real time as the pump pulls the system down. A live graph plots micron level over time, with the line trending downward toward the 500-micron target. The gauge connection status shows active and the pump is running.

Step 3: Pull Vacuum to Target

Run the vacuum pump until the system reaches the target vacuum level. For most modern refrigerants:

The 500-micron threshold is the industry standard for ensuring adequate dehydration of the refrigerant piping. Some manufacturers specify tighter targets (300 or 400 microns); always check the equipment installation manual.

The time required to reach target depends on system volume, hose size, pump capacity, and moisture content. A clean, dry system with a 12 CFM pump and large hoses may reach 500 microns in 10-15 minutes. A system with residual moisture may take significantly longer as the pump must boil off water at low pressure.

Tips:

• If the system stalls above target and will not pull lower, moisture is likely present. Continue pumping; the pump is evaporating water from the piping.
• If microns rise and fall cyclically, moisture is boiling off and re-condensing. Keep pumping until the level drops steadily.

Step 4: Perform the Decay Test

Once the system reaches the target vacuum level, close the valve between the pump and the system (or turn off the pump and close the isolation valve). This isolates the system from the pump.

The decay test begins. Monitor the micron reading over time. The BluVac app tracks the rise rate automatically.

Pass criteria: The system holds below 500 microns for the specified duration. A common standard is holding below 500 microns for at least 10-15 minutes with no significant rise, though some manufacturers specify longer hold times.

What rising microns means during decay:

[Visual Reference] BluVac decay test graph after the pump has been isolated. The X-axis shows elapsed time (minutes) and the Y-axis shows vacuum level in microns. A passing result shows a flat or nearly flat line holding below 500 microns for the full test duration (10-15 minutes). Minor upward drift that levels off below 500 indicates normal outgassing and is still a pass.

Step 5: Save and Return to measureQuick

When the decay test is complete and the system passes, save the evacuation data in the BluVac app. The BluVac app will pass the results back to measureQuick, where they are stored as part of the project record.

The evacuation data includes:

• Starting vacuum level
• Final vacuum level at end of decay test
• Decay test duration
• Pass/fail status
• Time-stamped micron graph

This data appears in the measureQuick project alongside any other tests (commissioning, diagnostics) performed during the same visit. When you generate a PDF report, the evacuation results are included.

measureQuick project view showing evacuation test results imported from BluVac, with pass status and micron graph

Step 6: Reinstall Valve Cores and Charge

After a successful decay test:

1. Close the vacuum pump valve if not already closed.
2. Reinstall the Schrader valve cores using the core removal tool.
3. Proceed with refrigerant charging per the equipment manufacturer's specifications.

Do not break vacuum by opening the system to atmosphere. Open the service valves to release the factory charge (for new installs) or begin charging from your refrigerant cylinder.

Video Walkthrough

• YouTube (measureQuick): (4,501 views, 14:32). Detailed walkthrough of the decay test process using BluVac 3.0, including multi-gauge support and interpreting decay curves

• YouTube (measureQuick): (13,113 views, 16:07). Updated evacuation best practices covering hose sizing, pump selection, and moisture management

• YouTube (measureQuick): (1,312 views, 12:26). Overview of BluVac 3.0 features including multi-gauge support and grid view for monitoring multiple points simultaneously

• YouTube (measureQuick): (79,558 views, 1:14:19). Jim Bergmann's comprehensive presentation on vacuum theory, evacuation procedures, and common mistakes

• YouTube (measureQuick): (5,975 views, 26:00). Jim Bergmann covers evacuation technique fundamentals and common field errors

• YouTube (measureQuick): (view count varies, 3:24). Real-world case study showing that proper evacuation does not have to be slow when the rig is set up correctly

Tips & Common Issues

My BluVac is reading erratically

Check the Bluetooth connection between the BluVac gauge and the BluVac app. Ensure the gauge battery is charged. If readings jump around, the sensor may need calibration or the gauge may be too close to a heat source. See the video "My BluVac is Reading Erratically!" (8:02) for troubleshooting steps.

The system will not pull below 1000 microns

This usually indicates moisture in the system. Continue pumping. The vacuum pump must boil off the water at reduced pressure, which takes time. If the system has been open to atmosphere for an extended period (especially in humid conditions), expect a longer evacuation. A triple evacuation (pull down, break with dry nitrogen, pull down again, break with nitrogen, final pull down) can speed dehydration in severe cases.

Decay test fails but I cannot find a leak

First, rule out your vacuum rig. Isolate the gauge from the system and see if the gauge holds vacuum on its own. Then check each connection point in sequence. The most common leak sources are flare fittings, Schrader cores that were not fully removed, and the pump isolation valve itself.

BluVac reports not appearing in measureQuick

Confirm that the BluVac integration is activated in measureQuick (Toolbox > Data Sharing Tools > BluVac System Evacuation App). The evacuation must be started from within a measureQuick project for the data to transfer back. If you run a standalone evacuation in the BluVac app without launching it from measureQuick, the results will not automatically appear in the project.

How do I save the BluVac report separately?

The BluVac app can save evacuation reports to Dropbox or Google Drive directly. See "BluVac Saving to Dropbox or Google Drive" (0:42) for setup instructions.

Related Articles

Prerequisites (complete these first):

• BluVac Integration - How to connect and activate BluVac with measureQuick

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

• A/C Installation Workflow - Full commissioning workflow that includes evacuation as a step

Related in the same domain:

• Static Pressure Screening - Quick TESP measurement without a full workflow
• NCI Quick Tests - NCI Air Upgrade quick test workflows

Need Help?

If you get stuck or this article does not answer your question:

• Check the Related Articles section above
• Contact measureQuick support: support@measurequick.com
• Schedule a training session with the measureQuick training team