Maintain clean, efficient airflow and dependable contaminant removal with Sentry Air Systems Model 300 Replacement Air Filters.

Designed for use with Sentry Air Systems 300 Series portable fume extractors and air filtration systems, these high-efficiency replacement filters help capture smoke, dust, fumes, airborne particulates and other hazardous contaminants generated during industrial, laboratory and manufacturing processes.

Available in HEPA, ASHRAE and ULPA filtration configurations, Model 300 Replacement Filters allow users to select the appropriate level of filtration performance for their specific application and air quality requirements. These filters are commonly used in welding fume extraction, soldering applications, pharmaceutical environments, powder handling, laser marking operations and laboratory ventilation systems.

Designed for Sentry Air Systems Model 300 Series including: 

• Portable Fume Extractors
• Wall Mounted Fume Extractors
• Benchtop Fume Extractors
• Ductless Fume Hoods
• Portable Clean Rooms

Key Features

• Designed for Sentry Air Systems Model 300 units
• Available in HEPA, ASHRAE and ULPA efficiencies
• Helps maintain optimal filtration performance
• Captures smoke, dust, fumes and airborne particulates
• Durable construction for industrial applications
• Easy replacement installation
• Supports cleaner and safer work environments
• Compatible with a variety of portable extraction systems

Filter Options

HEPA Filters
HEPA filters are designed to capture 99.97% of particles at 0.3 microns, making them ideal for fine particulate removal in a wide range of industrial and laboratory applications. Typical applications include:

• Solder smoke extraction
• Welding fumes
• Dust collection
• Pharmaceutical processing
• General particulate filtration

ASHRAE Filters
ASHRAE filters provide high-efficiency particulate filtration for applications where HEPA-level filtration may not be required. These filters offer an economical solution for capturing larger airborne contaminants while maintaining strong airflow performance. Typical applications include:

• General dust collection
• Light industrial filtration
• Educational labs
• Airborne particulate control

ULPA Filters
ULPA filters provide ultra-high-efficiency filtration and are capable of capturing 99.999% of particles at 0.12 microns. These filters are ideal for critical environments requiring maximum particulate removal.

Maintenance Recommendations

For best performance, replace filters according to system usage, contaminant load and airflow reduction. Regular replacement helps:

• Maintain filtration efficiency
• Improve airflow performance
• Extend equipment lifespan
• Reduce airborne contaminant exposure
• Support OSHA and workplace air quality requirements

Calculating Filter Efficiency

Efficiency of a filter is calculated by measuring the particle count downstream and upstream from the filter. The downstream count is divided by the upstream count then this number is subtracted from one then multiplied by 100 to create an efficiency percentage with this formula:

Filter Efficiency Comparison Chart

Particle Sizes

To illustrate the miniscule size of particles that these filters capture, one micron is equal to one millionth of a meter. The human eye cannot see particles smaller than 10 microns. Sizes of common particles are as follows:

• Human hair: 100-150 microns in diameter
• Emissions 1 – 150 microns
• Dust: 100 microns
• Pollen: 10 - 100 microns
• Spores: 3 - 40 microns
• Mold 3 - 12 microns
• Bacteria: 0.3 - 60 microns
• Pure oxygen 0.005 microns⁴