How to Measure Paint Booth Air Flow – A Guide (Includes Video)
Airflow is critical with paint booths to ensure that you are removing a sufficient volume of air to be in line with recommended safety guidelines like NFPA 33. Over time paint booth fans can have bearings or belts that wear that can eventually cause your paint booth to perform less effectively than it once did. Whether you need to measure paint booth air flow to determine your booth is running properly, to calibrate a booth that has been recently purchased, to troubleshoot a paint booth problem, or to verify for important record keeping it is good to know the tools you can use to measure paint booth air flow and how to measure paint booth air flow.
Tools to Measure Paint Booth Air Flow
Tools to measure paint booth air flow can be as simple as a vaneometer but can quickly become a few thousand dollar precision instruments depending on the sensitivity you need when measuring air flow. Will cover a few of the tools here for you to consider. Whichever tool you end up considering to measure air flow you want to choose a tool that is able to measure between 0 and 200 FPM with relative accuracy as most paint booths will have air moving anywhere between 50 to 200 feet per minute (not miles per hour) for common crossdraft or downdraft paint booths. We will offer up tools for measuring paint booth air flow in order of most economical to highest cost but greatest precision so you can consider which is right for you.
Dwyer Vaneometer
The Dwyer Vaneometer is one of the most affordable tools available to measure paint booth air flow. For around $35.00 it provides a simple, durable, easy way to quickly validate paint booth air flow. The Dwyer gauge is what we use in most field settings due to its affordable price point. That being said if you need a lot of precision in measuring paint booth air flow you will typically be better off to consider one of the other options we mention.
KanoMax 6800 Anemometer
Kanomax offers a variety of anemometers to measure air velocity and has greater accuracy than some of the lower cost options For great precision and accuracy their tools would be a good choice. This unit is offered online for around $900 and offers precision plus accuracy
Proster Anemometer
The Proster Anemometer is a digital affordable handheld anemometer that can determine wind speed between 0 – 5860 feet per minute making it well suited for paint booth air measurement. though it starts reading around 35 feet per minute which is a bit of a high starting point for some paint booths (like downdrafts)
How to Measure Paint Booth Air Flow
The key to getting good readings when measuring paint booth air flow is to take multiple measurements. ou will want to check the flow of air throughout your paint booth as a well designed paint booth will have similar airflow throughout it. You also need to know how each tool will work. The important thing to remember is that air should be moving across the vanes or spinning portion of your gauge. So for the vaneometer air would flow as shown in the picture below where as with the other units air would have to move as shown in the other photo. Remember with a downdraft booth a vaneometer will typically not work because of its design. See video for details on measuring air flow.
Once you have measured the air flow you will want to see what the original design specification for your paint booth airflow was. Typical paint booth air flow values can be read about here or just remember typically a cross draft paint booth will have air flow of about 100 Feet Per Minute (based on the width and height of the booth), a downdraft will have air flow of about 50 feet per minute and a side downdraft will also have air flow of about 50 FPM (both based on the length and width of the booth).
What to Do if Paint Booth Air Flow Seems far From the Standards Referenced
If your paint booth’s airflow is significantly slower or faster than the suggested speeds mentioned above, you will want to review your paint booth for potential causes of the problematic air flow. Common areas that can cause underperformance include painting with filters that have excessive overspray build up. Additionally, it may be that your fan’s belt is in need of tightening or replacement. Finally, it may be that your paint booth fan has overspray build up on it reducing the fan’s performance or the fan motor has worn out and needs replacement (which can be checked using a voltmeter). While this is just a sampling of potential problems, this should give you a few ideas of what can cause underperformance in paint booth air flow.
On the other hand, if your paint booth is moving air at a significant volume of air above the standards mentioned it may be for design purposes due to the nature of what you are painting. If there is not a design reason for the fan moving air as fast as it can, you could potentially have a variable pitch drive on your paint booth fan that has been set at the fastest speed without needing to be set their (please review booth information with the original provider of the equipment before slowing down the paint booth fan). If this is not the reason it may be something changed with the booth over time whether it be a duct run or something similar.
Final Thoughts
Ultimately knowing how to measure paint booth air flow can help you verify your paint booth is running right and provide one potential way to start to determine if your paint booth is having issues. By knowing an overview of the tools that are available, how to use them, as well as the expected air flow for different booths you can be better informed about your paint booth and it’s performance. If you have further questions contact us for additional help.