Space Heaters for Rooms, Garages and Shops

The right space heater depends on what you’re trying to keep warm: a whole room, just you at the bench, a bedroom in the evening, or a garage that hits single digits. In the Flathead Valley, where winter lows average 16°F, the wrong pick either can’t keep up or runs you out of breaker. Start with the space, then the heater.

Heating a room fast: ceramic fan heaters

A ceramic heater has a fan blowing across a hot ceramic element, so it moves warm air into the room quickly. These are the everyday plug-in heaters, and WBC has several:

• Best Comfort ceramic heater (black): a plain, compact room heater.
• Best Comfort oscillating heater and the oscillating ceramic tower heater: the head swings side to side, which spreads the heat more evenly across a room. The trade-off is noise; heaters with oscillating fans tend to be the loudest.
• Vornado Vortex heater, 1,500 watts: uses Vornado’s vortex air circulation to move warm air around the room.
• PowerZone PTC-700, 1,500 watts: a portable 120-volt heater that draws 12.5 amps.

Quiet, steady heat for a bedroom: oil-filled heaters

An oil-filled heater looks like an old radiator. Electricity heats oil sealed inside, and the fins give that heat off slowly and steadily. It takes longer to warm up than a ceramic heater, but it’s quiet, it keeps giving off warmth after it shuts off, and there’s no glowing element or flame. That makes it the pick for warming a bedroom in the evening or an office; it still gets turned off when you go to sleep. The fins do get hot, so keep kids and pets off them.

WBC’s full-size oil-filled heater runs at 600, 900 or 1,500 watts, so you can turn it down once the room’s warm. The mini oil-filled heater is for a small room or office, with the same clearance as any heater.

Warming you, not the room: quartz and infrared heaters

Radiant heaters warm the people and things in front of them rather than the air, so you feel them almost as soon as they’re on. In a drafty room or at a workbench in a cold shop, where the air won’t stay warm anyway, radiant heat is what reaches you. WBC carries the Best Comfort tower quartz heater and the Best Comfort infrared quartz heater.

The shop, barn or well house: the milkhouse heater

The PowerZone milkhouse heater is the plain, tough little fan heater that lives in shops, barns and outbuildings across Montana. It’s simple and easy to move. Two cautions. Keep it well clear of hay, straw, sawdust and anything else that burns, the same three feet as anywhere else, and don’t leave it running where nobody’s around to check on it. And a damp spot, like a wash bay or a wet floor, needs a heater designed for wet locations, so check the label before you set one there.

The garage: 240-volt heat

A 1,500-watt plug-in heater can take the edge off at the bench, but warming a whole garage in January usually takes more, and that’s where 240-volt heat comes in:

• DH 4,000-watt, 240-volt electric heater
• 240-volt ceiling-mount garage heater: up off the floor, out of the way of the truck, the bench and the shop vac.

A new 240-volt heater generally wants its own dedicated circuit. Have an electrician confirm your supply voltage and the circuit before it goes up. If you’re replacing an old heater, match its voltage and its phase; both are on the old heater’s label, and most homes are single-phase.

How big a heater?

A common starting rule is about 10 watts per square foot of floor, which assumes 8-foot ceilings. By that rule a 1,500-watt heater suits about 150 square feet, and a 4,000-watt heater about 400. Two adjustments move it:

• Poor insulation: figure about 12 watts per square foot instead.
• Taller ceilings: add roughly 25 percent.

Treat that as a rough start, not a promise. A tall, drafty pole barn needs a lot more than the floor area suggests, and a well-insulated garage less. Too small a heater runs all the time and never catches up; too big a heater overshoots the thermostat setting.

What it costs to run

A heater uses its wattage for as long as its element is on. A 1,500-watt heater running for an hour uses 1.5 kilowatt-hours. A thermostat is what saves you money: it shuts the heat off once the room reaches the setting and turns it back on when it cools. Pick the lowest setting that keeps you comfortable, and use an eco mode or timer if the heater has one.

Running a heater safely

• Keep at least three feet between the heater and anything that burns: furniture, curtains, bedding, clothes.
• In a garage or shop, keep it away from paint, gas cans and solvents.
• Plug it straight into the wall. A 1,500-watt heater draws 12.5 amps, most of an ordinary household circuit. No extension cords or power strips, nothing else on that outlet, and go easy on whatever else shares the circuit; a toaster or a shop vac on another outlet of the same circuit adds to the load.
• Look for overheat protection, tip-over shutoff and a testing lab mark like UL, ETL or CSA.
• Turn it off when you leave the room or go to bed.

Propane: outdoors, and the right parts

WBC’s Mr. Heater 8,000 BTU propane cooker is an outdoor appliance. Propane appliances that aren’t vented put carbon monoxide into the air they burn in, so a propane cooker or patio-type heater stays outside, never in the garage, the shop or the house.

For propane hookups, WBC has a Gas Mate quick connector and a 3/8-inch hose assembly. An LP quick connector is not the same size as an air hose fitting, even when it looks it, so match both to what the appliance calls for.

If you run a kerosene heater, WBC carries K-1 kerosene in 2.5-gallon cans. Burn the grade your heater’s maker specifies.

The Pick

For a living room, take a Best Comfort ceramic or oscillating heater, the Vornado Vortex or the PowerZone PTC-700. For a bedroom in the evening, the oil-filled heater. For warmth at the bench, a Best Comfort quartz heater. For the shop or outbuilding, the PowerZone milkhouse heater. For the garage, the DH 4,000-watt or the ceiling-mount 240-volt heater on its own circuit.

Frequently Asked Questions

What kind of space heater is best?

It depends on the job. Ceramic fan heaters warm a room fast, oil-filled heaters give quiet, steady heat for bedrooms, and quartz or infrared heaters warm you directly at a chair or workbench.

How many watts do I need?

Start at about 10 watts per square foot with 8-foot ceilings, so 1,500 watts for about 150 square feet. Figure about 12 watts per square foot for a poorly insulated space and roughly 25 percent more for tall ceilings, then treat the number as a starting point.

Does a space heater use a lot of electricity?

It uses its wattage whenever the element is on: 1,500 watts for an hour is 1.5 kilowatt-hours. A thermostat cuts that by cycling the heater off once the room is warm.

Can I plug a space heater into an extension cord?

No. Plug it directly into a wall outlet and keep other devices off that outlet. A 1,500-watt heater draws 12.5 amps, cords and power strips can overheat, and other big loads on the same circuit add up.

Can I use a propane heater in my garage?

Not a patio heater or an unvented propane cooker. They put carbon monoxide into the space. For garage heat, use an electric garage heater or a gas heater made and vented for indoor use.