Prestaciones accesorias

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Keep Combustibles Clear

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Heating and Ventilation

central-heating system is a major project, typically only worth the effort if you’re heating a sizable shop.

If you’re building a new shop that will have a concrete floor, you might consider turning that slab into a giant radiator by installing a radiant-floor heating system. This system heats your shop with a central gas- or oil-fired fur-nace or heat pump that drives hot water through a long length of plastic tubing that is laid into your slab at the time it is poured. The piping is unobtrusive and maintenance-free, and the system is efficient and makes an otherwise cold concrete floor more comfortable to work on. Unfortunately, you can’t retrofit this system into an existing floor.

Portable HeaterS

Because of their low purchase cost and ease and flexibility of use, portable

Portable electric space heaters are probably the most popular and easy way of heating a small woodshop. The unit on the left has two quartz elements and a fan and warms up very quickly.

The radiator-like unit on the right encloses its elements in fluid-filled chambers for greater safety around wood dust.

heaters are the most attractive solution for small woodshops. Because of their popularity for heating homes and patios as well as workshops, portables come in as many styles as cowboy hats at a rodeo.

The amount of heat these units put out varies considerably, from a few hundred BTUs to thousands. They also run on dif-ferent types of fuel: electricity, kerosene, or propane. But every type is not right for every kind of woodshop. You should consider the cost, safety, and practicality of operation before selecting a portable that’s best for you.

Electric portables Probably the most versatile heaters on the market are of the portable electric variety. There are basi-cally two types: units that have exposed heating elements and fans and those that use enclosed elements in fluid-filled chambers.

Heating Your Shop

• Exposed-element heaters This type of unit provides shop heat through a combination of convection (heat trans-ferred through the medium of the air) and radiation (heat transferred directly, the way we feel the warmth of the sun streaming through a window). These small electric space heaters come in a tall variety with reflectors behind the ele-ments, which help direct heat radiation outward, and in a small box or cube type that relies on metal wires or ceramic elements. Both provide a good means of heating a small workspace rapidly.

• Enclosed-element units The en-closed style of electric heater contains

the elements within a chamber or pipe filled with either water or oil. This pretty much eliminates the fire danger, but it also limits the type of heat output to convection only. Some portables look like small radiators on wheels, and the other popular style is a long, low base-board-type heater. Higher-output 220v versions of these heaters are often used to heat all-electric houses. Because of the volume of heat necessary to get the fluid hot, it takes a while for these units to heat up. But after the initial warm-up pe-riod, they give off an impressive amount of heat and stay warm long after you’ve switched them off.

The downfall of these units is in pro-viding the volume of heat necessary to heat the air in even a modest-size shop.

They can be used as a primary source of heating only if your shop is quite small, say, two-car-garage size or less, and well insulated.

Propane and kerosene portables Portable stoves powered by liquid kerosene or bottled propane are rela-tively inexpensive to buy, easy to start up, and cheap to run. And they’re also light enough to easily move around the shop to supply heat closest to where it’s needed. Unfortunately, because these are unvented stoves, the noxious products of combustion are produced along with co-pious amounts of heat.

Some woodworkers use portable stoves inside their shops, although manufacturers clearly state with these units that they are not to be used inside A bottled propane space heater

is relatively inexpensive to run, but it should be used only in an open-air or a very well ventilat-ed shop: The unventventilat-ed heater expels noxious gases along with heat that can be both un-pleasant and fatal to breathe.

Heating and Ventilation

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shop heat off at the end of the day and heat only the space in which your as-sembly is sitting. You can use an electric wallboard heater or any space heater that has a thermostat to heat the small space.

By making your glue-up room only as large as it need be and by thoroughly insulating its walls, you’ll save on energy because the heater will run only a small amount of the time.

unventilated spaces. Even if you make a practice of thumbing your nose at official recommendations, this is one to heed.

The gases put out by these stoves can at best leave you with a headache and at worst knock you out and kill you via asphyxiation.

Another more subtle problem with kerosene stoves in particular is that they add moisture to the air along with heat.

This isn’t necessarily a bad thing because heated winter air is typically bone dry.

But if the wood projects you build are sensitive to moisture—if you’re a luthier, for example—remember that kerosene heat is likely to increase the humidity of your shop.

Task heating Like light, heat can be applied to certain special situations.

This saves energy and directs the heat to where it’s needed most. Finishes and most wood glues are temperature sensi-tive and don’t dry and cure well below a certain temperature—typically 55ºF. If you leave an assembly to dry, say, over-night in an unheated shop, you might get an unhappy surprise the next day when you take the clamps off to find that the glue bonds are still tacky and weak.

Worse yet, improperly cured glue bonds can fail sometime in the future.

An interesting and useful addition to any shop that’s unheated or inadequately warm during the coolest months of the year is to build a separate, heated glue-up room. A glue-glue-up room, as small or large as the biggest assembly you plan to put inside it, allows you to turn your

If you live in a cold climate, using a sepa-rate heated glue-up room allows you to properly dry glued-up assemblies and cure clear-finished projects without having to heat the entire shop.

Heating Your Shop

Similarly, you can enclose your finish-ing area and heat it at a different tem-perature than the rest of your shop, so finishes will dry and cure faster. Warm the area with heat lamps in portable light fixtures or with an enclosed-element heater that is safe for use around com-bustible vapors.