Choosing Airflow Designs

Airflow designs are a defining element of any spray booth, so it’s one of the first things finishing operators need to consider when upgrading to a new booth.

While there are only a handful of options when selecting a type of booth, each one carries a unique set of advantages and possible drawbacks. Airflow systems impact every aspect of a booth’s operation, so companies should carefully weigh how their chosen design will affect operating costs, quality of results and workplace safety.

Airflow Designs

Crossdraft

Downdraft

Semi-Downdraft

Modified Downdraft

Crossdraft Airflow Designs

Recommended for:
All Industries + Basic Finishing Requirements

  • Cost-Efficient Performance
  • Minimal Installation Requirements
  • Simple Maintenance and Upkeep
The standard in airflow designs, a crossdraft spray booth can be designed to handle a wide variety of uses and is typically recommended for parts that require a basic finishing quality and application process. The minimal installation requirements needed for this style of airflow design make it an ideal solution for most finishing facilities. The term crossdraft refers to how the air travels through the booth: horizontally along the “cross-section” of the booth.
Crossdraft Airflow 1

Stage 1

Air enters through the front of the booth and then through the intake filters. As the air passes through the filters contaminants are captured. This is accomplished without sacrificing the quality or volume of the airflow itself.

Crossdraft Airflow 2

Stage 2

Horizontal airflow intake causes air to flow uniformly over painted parts and through a rear exhaust chamber. The exhaust chamber incorporates exhaust filters so that the air can be filtered from any paint overspray as it passes through the chamber.

Crossdraft Airflow 3

Stage 3

As air passes through the exhaust filter, it is pressed through a continuous filament glass fiber with an open weave pattern. This airflow design prevents face-loading and fogging by changing the direction of paint-laden air throughout filtration. The clean, filtered air now continues through the exhaust plenum, which is designed to balance airflow throughout the entire booth.

Animated image depicting airflow through a crossdraft spray booth.
Air movement through a crossdraft booth.

Downdraft Airflow Designs

Recommended for:
Aerospace and Automotive + High-Quality Finishing Requirements

  • Powerful Performance
  • Pit Installation Requirements
  • Moderate Maintenance and Upkeep
Like crossdraft airflow designs, a spray booth with downdraft airflow can accommodate a wide variety of parts and uses. However, downdraft spray booths are typically recommended for parts that require a higher quality finish. Notably, conventional downdraft airflow designs require a below-ground pit for proper operation, which creates additional installation concerns. The term downdraft refers to the direction of airflow in a downward movement from the ceiling down towards the floor of the booth.
Downdraft Airflow 1

Stage 1

Airflow is introduced into the booth’s air supply plenum and drawn through the supply filters located in the ceiling, which acts as a diffusion media. The multiple synthetic layers of filtration are the result of combining a pre-filter, which consists of a high-performance cover mat, with a final filter of progressively structured media, which is thermally bonded and treated with a special adhesive tackifier.

Downdraft Airflow 2

Stage 2

The clean air continues down and around the part, collecting overspray along the way. This overspray is then pulled downwards through exhaust filters located in a grated pit at floor level. As air passes through the exhaust filter, it is pressed through a continuous filament glass fiber with an open weave pattern for maximum efficiency.

Downdraft Airflow 3

Stage 3

To prevent face-loading and fogging, paint-laden air is forced to change direction many times as it passes through the filtration system. Once in the filtration system, it passes through an exhaust fan designed specifically to accommodate the static pressure of the exhaust filters. Spray Systems precisely matches the size of the motor and fan performance for each booth, so that each fan operates at dBa levels well below OSHA limits.

Downdraft Airflow
Air movement through a downdraft booth.

Semi-Downdraft Airflow Designs

Recommended for:
Aerospace, Automotive, and Large Equipment + Complex Finishing Requirements

  • Balanced Performance
  • Minimal Installation Requirements
  • Simple Maintenance and Upkeep
Semi-downdraft spray booths combine the two airflow designs described above (crossdraft and downdraft) to strike a balance between efficiency, speed, and quality. Because this airflow design doesn’t require a pit for operation, like a conventional downdraft booth, this booth can be easily installed in most facilities. The term semi-downdraft refers to how air passes over the part with downward airflow before being exhausted via horizontal airflow.
Semi Downdraft Airflow 1

Stage 1

Air is drawn through the top of the booth via a ceiling supply plenum and passes through intake filtration comprised of multiple synthetic layers. This ensures that clean air is introduced into the system while providing uniform airflow throughout the booth.

Semi Downdraft Airflow 2

Stage 2

As air passes through the booth and towards the exhaust filters, uniform airflow collects overspray around the finishing product and moves particulate away from the spray environment. These exhaust filters utilize a continuous filament glass fiber with an open weave pattern to further prevent face-loading via saturation.

Semi Downdraft Airflow 3

Stage 3

Paint-laden air is forced to change direction multiple times as it passes through the exhaust system, reducing the occurrence of fogging. Whisper-quiet exhaust fans direct air through the exhaust plenum, which is designed to facilitate balanced airflow and energy efficiency.

Animated image depicting airflow through a semi-downdraft spray booth.
Air movement through a semi-downdraft booth.

Modified Downdraft Airflow Designs

Recommended for:
Large Equipment and Automotive + High-Quality Finishing Requirements

  • Powerful Performance
  • Minimal Installation Requirements
  • Additional Maintenance and Upkeep
Modified downdraft airflow designs are similar to conventional downdraft systems, resulting in powerful performance for higher-quality finishes. Compared to conventional downdraft booths, modified downdraft booths have the added benefit of not requiring a pit for installation. However, this means they require additional ductwork to operate efficiently which demands more intensive maintenance and upkeep. Sometimes referred to as a “side downdraft” booth, the term modified downdraft refers to how airflow travels towards the floor before being diverted to side exhaust plenums
Modified Downdraft Airflow 1

Stage 1

Air is drawn through the top of the booth via a ceiling supply plenum and passes through intake filtration comprised of multiple synthetic layers. This ensures that clean air is introduced into the system while providing uniform airflow throughout the booth.

Modified Downdraft Airflow 2

Stage 2

The air continues down and around the product through precisely balanced airflow, collecting overspray along its path and pushing it away from the spray environment. After reaching the floor, the downdraft airflow is diverted towards side exhaust plenums, which are outfitted with exhaust filters made of continuous glass fiber woven into an open pattern to prevent saturation and poor filtration.

Modified Downdraft Airflow 3

Stage 3

As the air passes through the filters and within the exhaust plenum, any remaining air-laden paint is forced to change direction many times via exhaust fans to further ensure proper filtration and prevent the occurrence of fogging. Clean air is then filtered outside of the spray booth.

Animated image depicting airflow through a modified downdraft spray booth.
Air movement through a modified downdraft booth.

Custom Paint Booth Designs

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