General Information

The AIR-VAC® (patent pending) is an improved air powered vacuum for safe excavation of all types of buried objects including pipes, cables, and even tree roots. The AIR-VAC® used in combination with the AIR-SPADE® forms a powerful non-damaging team. The AIR-VAC® has a number of key features including:

  • Utilizes the patented AIR-SPADE supersonic nozzle to achieve superior performance.
  • Is powered by a standard portable air compressor; i.e. does not require a separate engine and expensive roots blower.
  • Readily vacuums 1 to 2 cu ft per min of materials such as dirt, sand, gravel, rocks, or water.
  • Has dust free operation through using a washable polyester filter that has a high loading capacity and filters to 99.5% at 0.2 to 2 micron.
  • Has a durable powder coated steel tank.
  • Has a high suction velocity in the hose, ~ 10,000 feet per minute, which moves material readily, even with long hoses.
  • Has replaceable UHMW wear plates at dirt impact points.
  • Has a large dump door that opens to allow easy emptying back into hole.
  • Has a simple exhaust silencer to provide quiet operation with air and noise directed away from workers or passersby.
  • Has an injector that is removable for easy transportation and storage.

The AIR-VAC® is available in a range of sizes as follows:

Portable AIR-VAC®

The portable AIR-VAC® is designed especially to be easily deployed where the larger vacuum trailers or trucks cannot go. It fits through 32-inch wide gates or doors for access to backyards or indoors; yet it holds ¼ cubic yard of spoil (475 to 600 lbs), enough to dig a pothole 12 inches in diameter by over 6 ft deep. Its lightweight tank, dual handles, and 13-inch pneumatic wheels allow easy, balanced movement by one or two men.

Truck / Trailer Mounted AIR-VAC®

For larger storage volumes, this AIR-VAC® is available in a horizontally oriented tank configuration suitable for mounting in a pick-up truck or small open or enclosed trailer. It holds 1 cubic yard of material with larger sizes available on special request.

Hand-Held AIR-VAC®

Under development is a hand-held unit for very close quarters such as trench rescue applications.

Features of AIR-VAC® Operation

It is important to note that when conveying material, an air-injected vacuum system actually operates at a mid-point on its head flow curve, like a centrifugal fan. It does not operate at either its peak vacuum nor its maximum flow points as illustrated below. This operation is unlike a positive displacement, i.e. roots type, blower that will maintain substantial hose velocity even at peak vacuum. For typical air-vacuum excavation applications such as utility potholing, a hose velocity on the order of 10,000 feet per minute at a working suction head of 5 to 6 inches of Mercury is sufficient.

It is, therefore, not generally recommended to dead head the air-vacuum system since the velocity drops to zero allowing the material to fall out of the air stream and deposit in the hose. The “plug and chug” method may work for very short hose lengths, but can be dangerous as the plug of material flies through the hose. High vacuum levels (30 in Hg being the maximum equal to perfect vacuum) can also be dangerous to operators if exposed to the body.

For air-injector vacuums, it is also the inlet flow through the hose that counts, not the discharge flow from the injector that includes the amount of compressed air supplied. When comparing air-injected vacuum systems, it is important to understand each manufacturer’s specifications carefully.