Woodworker's Journal 2006-30-2, страница 76
7 »SH1P the overspill from dust-spewing power tools, they're definitely NOT a replacement for primary dust collection equipment. And even with ventilation/air filtration running, you MUST wear a respirator whenever you raise clouds of dust in the shop. Shop Ventilation One of the simplest ways of reducing airborne fine dust in your shop is to catch it and blow it outdoors. Shop ventilation works by dilution, replacing dusty air with clean air from outside. This low-tech method requires only a strong fan set in an open window or door, as shown below. The fan sucks up the airborne dust before it has a chance to settle — or get breathed in. Fresh air enters through an open inlet, preferably located on the opposite side of the shop from the fan. Unfortunately, shop ventilation is only practical when temperature and humidity are moderate; otherwise, heated or air-conditioned air is blown outdoors. A large household box fan (set on its highest speed) will adequately exhaust dust from a small- to medium-size shop. To prevent clouds of obnoxious dust from blowing into your home or neighbor's yard, tape a standard fiberglass-media furnace filter on the inlet side of your box fan. Although even a powerful fan moves a great volume of air, it has little power for capturing dust A simple boi fan in a window works to exhaust dust in the shop and offers a good start on ventilation, especially in the small shop. at its source. Therefore, move your dust-generating source — say, the workbench where you do your power and hand sanding — as close as possible to the fan. You can further increase a ventilation fan's dust-capturing efficiency by putting behind your work area a second fan thai will blow fresh air past you and dusty air toward the exhaust fan, as shown above. Tip: If you have heavy sanding to do, and/or are using power tools that are difficult to connect to primary collection (angle grinders, rotary tools, etc.), you'll get the best fine-dust ventilation by simply doing your sanding outdoors on a nice day. Air Filtration Devices Also known as an "air cleaner," an air-filtration device (AFD) is basically a box-like cabinet with a fan and filters. Dusty shop air is pulled in and passes though a pair of filters that strain out fine wood dust. Because new air isn't introduced from outdoors, a heated shop slays warm and an air-conditioned shop stays cool. Ideally, an AFD exchanges all the air in the shop many times per hour, to keep free-floating dust in check. AFDs are designed to be installed near the ceiling, where they create air circulation and don't get bumped into. For better air circulation (and hence, filtering) in a large shop, it's prudent to install a pair of AFDs on opposite walls, with their inlets pointing in opposite directions. AFDs are rated by their air-moving capacity, (e.g., 1,200 cubic feet per minute [cfm]) and come in many sizes. Larger units sport bigger fan motors, larger filters and have higher CFM ratings. Generally speaking, the more power sanding you do in your shop, the larger your AFD needs to be for good dust-filtering performance. Some units, such as the JDS Air-tech 10-16 shown below, come with multi-speed motors that let you set the performance of the unit to suit the amount of dust in the air. Air-filtration devices (AFDs), like JOS's Air-tech 10-16, are designed to be installed near the ceiling. If you're a hobbyist who works in a small space, or a do-it-yourselfer who occasionally does sanding inside the home, consider getting a compact portable .AFD, such as the ShopVac Portable Air Cleaner. You can easily set this unit on a worktable or move it to wherever you're working. Comprehensive Dust Control Strategies By now, it should be clear that simply buying and hooking up any single dust collector or air filtration device isn't going to fully take care of all your shop's sawdust problems. Uke a horse and carriage (or iPod and computer), primary and secondary collection and control devices and methods are meant to work together to achieve a clean, healthy and fire-safe shop environment Today's Shop continues on page 80... 76 April 2006 Woodworker's Journal |
