Drilling in masonry, stone or concrete with rotary hammers and hammer drills generates a large amount of dust which may contain high levels of crystalline silica and creates a hazard for everyone in the vicinity. Vacuum dust controls exist for rotary hammers and hammer drills. These controls consist of a vacuum, with a disposable filter (a high efficiency particulate air, HEPA, filter is often an option and recommended where practical), attached to a shroud that fits over and partially encloses the bit, or tool. The vacuum draws air and dust from the bit, the point of dust generation, into the shroud where it is transported through tubing and into the vacuum's bag or reservoir.

(Photo courtesy of ELCOSH)

Bosch 3/4-inch SDS-plus Rotary Hammer with Dust Collection

• Used for drilling concrete
• Cost: $290.00 (verified 11/2009)
• Maximum bit diameter (for concrete): 3/4-inch
• Revolutions per minute: 0 – 1,100
• Blows per minute: 0 – 4,400
• Impact energy: 1.8 foot pounds
• Power requirements: 120 volts, 6.1 amps
• Weight: 7.4 pounds
• Dust collection:
  • Dust canister with microfilter – filter should be replaced after 15 hours of use
  • Optional vacuum adapter dust canister can be used, instead of dust canister, to connect the rotary hammer to a vacuum via a 1-1/4 or 1-1/2 inch hose
• Sound pressure level: Likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Bosch Airsweep™ Wet/Dry Vacuum

• Cost: $530 (verified 11/2009)
• Air flow rate: 130 cubic feet per minute
• Water lift: 100 inches
• Hose diameter: 1.38 inches (35 millimeters)
• Power requirements: 120 volts, 11 amps
• Weight: 42 pounds
• Filtration: standard set of two filters remove 99.93 percent of 3.0 micron particles, a set of two HEPA filters can be purchased for approximately $200
• Sounds pressure level: 69 dBA

Hilti TE 80-AVR/TE 70-ATC and TE 40-AVR/TE 30-AVR Combihammer

• Used for drilling and chiseling concrete, stone and masonry
• Cost: call for a quote
• Hilti VC 20U and VC 40U wet/dry vacuum cleaner
• Dust collection: used with TE DRS-S adapter and Hilti VC 20U or VC 40U wet/dry vacuum cleaner

Hilti VC 300-17X wet/dry vacuum cleaner

• Cost: $1,649 (verified 5/2018)
• Air flow rate (maximum): 314 cubic feet per minute
• Length of vacuum hose: 16 feet
• Dust capacity: 17 gallons
• Weight: 63.1 pounds
• Filter cleaning: automatic, every 7.5 seconds
• Power requirements: 120 volts, 10 amps

 Metabo BHE20 IDR Electronic Rotary Hammer with Dust Extractor

• Used for drilling concrete
• Cost: call for a quote
• Maximum bit diameter (for concrete): 25/32-inch
• Revolutions per minute: 0 – 1,000
• Blows per minute: 0 – 4,900
• Impact energy: 1.2 foot pounds
• Power requirements: 120 volts, 3.8 amps
• Weight: 7.7 pounds
• Dust collection:
  • Dust box with reusable pleated filter – frequency of cleaning and replacement depends on use
• Rubber-coated Metabo VibraTech (MVT) handle for vibration damping and increased comfort
• Sound pressure level: Likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Vacuum dust control systems can have either positive or negative effects on productivity, but definitely improve the quality of the work by capturing large amounts of airborne dust, which allows a cleaner, more efficient means of drilling into concrete.

Ventilation for construction tools is often misunderstood. There are some key concepts that can help:

• The vacuum must be located as close to the dust generation as possible to be effective. A shroud may be needed to contain the dust so the vacuum can capture it. The shroud must be kept as close to the work surface as is practical to provide adequate dust capture. The shroud should be connected to the vacuum with 2-inch, or greater, diameter tubing with a relatively smooth interior.
• The particles that can do the most damage in the lungs are small enough to penetrate the filters found on many shop vacuums. Additionally, some inexpensive shop vacuums pull the dust through the motors, which can destroy the vacuum on really dusty jobs, eliminating any initial cost savings.
• For dust containing harmful particles like silica, it is important to use as high efficiency filters as practical. The best available are called HEPA (High Efficiency Particle Air) filters because they capture 99.97% of the most penetrating particles. But HEPA filters also create a greater pressure drop and decrease in air flow rate because it is more difficult to pull air through these denser filters so capture velocity may be reduced. They also require pre-filters to extend the life of the HEPA filters, which are more expensive than other filters. Studies have shown that it may be more effective to direct the exhaust air out of the work area than to attempt to add HEPA filtration for a tool where it isn't an integral part already. HEPAs require routine cleaning or disposal of prefilters, which can cause exposures to those performing the filter maintenance.
• For operations that generate large amounts of dust, cyclonic collection units, if available, may be the best solution. Rather than require more expensive filters and bags that must be frequently changed, cyclonic units spin the particles and drop them into cheap bags that need to be replaced far less frequently because loading of the bags does not cause a pressure drop.
• Vacuum performance must be monitored on a regular basis. A vacuum with a pressure gauge allows for frequent and easy monitoring of air flow. For high dust generating tasks, dust caked on the filter may reduce flow to a level where it no longer provides adequate dust capture. Automatic and manual filter shakers, coarse pre-filters and cyclonic collections units are available with some vacuums and may help maintain the air flow rate.

• Reinforced Concrete
  • Drilling concrete
    • Construction dust
    • Silica