Space Heaters – Dangerous? Fire-causing? Cost-effective? Legal?

By Eric Weld, MassLandlords, Inc.

Space heaters of numerous types and technologies have long served as supplemental warming alternatives in cool months for budget and resource-conscious homeowners and renters of relatively smaller dwellings.

Portable electric space heaters have come a long way since this 1960s vintage model.

And while the use of portable space heaters raises a lot of questions about safety and efficiency, these warming devices have been helping offset cold New England temperatures for more than a century.

(For the sake of clarity, when we refer to space heaters in this article we are referring to portable space heaters for residential use, not electric baseboards, mounted heaters on walls, floors or ceilings, or wood or pellet-burning stoves, all of which can also be considered space heaters. Nor are we referring to outdoor natural gas, propane or kerosene-burning high-powered commercial blower heaters such as those you might find on a construction site or a football game sideline.)

Home space heaters have come a long way since the first gas-fueled devices warmed drafty domiciles in the mid-19th century. Those first gas heaters were basically portable Bunsen burners that heated the surrounding air with an open flame. The first electric space heater was invented by Albert Leroy Marsh in 1905. Marsh’s relatively safer and more efficient device used resistance to heat up a chromium alloy that gave off heat around it.

Today’s space heaters have made many improvements to address safety and efficiency concerns. They have also expanded in terms of type with a huge variety available – electric, infrared, oil-filled, propane, natural gas and kerosene.

There are convection heaters that draw in air, warm it, then circulate it throughout a room; infrared heaters that project a beam of heat directly in front of the unit; and electric heaters that warm an element inside a reservoir of oil and circulate the resulting heat. There is an array of brands – DeLonghi, Holmes, Honeywell and Lasko among those recommended by Consumer Reports -- all offering a range of safety and efficiency features.

Most modern space heaters come with safety features including tip over switch, timers and over-heat shut-off systems.

Space Heaters in the State Sanitary Code

Still, despite all the changes and improvements over time, and the broadening of options, portable space heaters have not escaped their reputation for danger.

Presumably, that’s one reason portable space heaters may soon be prohibited from use in rentals in the Department of Public Health’s Minimum Standards of Fitness for Human Habitation, more commonly known as the state sanitary code. MassLandlords recently wrote about this year’s proposed changes to the code, which include listing “portable space heaters, parlor heaters, cabinet heaters, room heaters” among devices that do not meet sanitary code requirements.

Such across-the-board changes, while they may aim to address safety, run the risk of literally leaving many New Englanders out in the cold when, for instance, their home heating system fails and they are temporarily without warming options. Or the countless budget-limited folks who can’t afford a new high-efficiency furnace or a winter’s worth of fuel and depend on portable heaters as a way of staying warm for less up-front money.

Space Heater Questions

There are many questions around space heater use, especially for renters and landlords trying to save money, stay safe and comply with sanitary code regulations and proposed changes. Among the most frequently asked: Are space heaters dangerous? Do space heaters cause fires? Do space heaters save money? What types of space heaters are best? Electric infrared? Oil-filled? Convection or radiant? Which brands?

The answer to these questions is the same as it is to so many of life’s mysteries: it depends. To help sort and clarify some of the encyclopedic information about space heaters, we take a deeper look here at these questions one at a time.

Do Space Heaters Cause Fires?

This might be the most common space heater concern. Examples of space heaters themselves causing fires, when following safe usage guidelines, are relatively rare. Some space heater models, like the Vornado Air VH110 vortex electric heater and the Duraflame electric heater, have heated up excessively causing melting and fire in some cases due to faulty manufacturing. Both of these models were recalled in 2014.

However, with unsafe usage, portable electric heaters are more dangerous. They are involved in about 1,100 fires every year, resulting in about 50 deaths and numerous burn-related emergency room visits, according to statistics from the U.S. Consumer Product Safety Commission (CPSC).

While space heaters accounted for about 44 percent of all home fires involving heating equipment between 2012 and 2016 (including space heaters, furnaces and heating stoves), those fires resulted in a much higher rate of death and injury – 86 percent of civilian deaths and 78 percent of civilian injuries, according to National Fire Protection Association statistics.

But space heaters aren’t the only household appliances that cause fires. In fact, heating equipment is the second leading causal factor in home fires, accounting for 9.1 percent of the 371,500 residential fires in the U.S. in 2017, estimates the U.S. Fire Administration. Cooking accidents are by far the leading cause of home fires, accounting for 51.6 percent.

Other common home appliances that contribute to or cause fires include dishwashers, clothes dryers, microwave ovens, refrigerators and toasters.

Are Space Heaters Dangerous?

This is related to the above question, and one would have to conclude that space heater use is dangerous as evidenced by all those fires, deaths and emergency room visits cited in statistics above.

Because of what they do – e.g. create intense heat in order to warm the surrounding air – all portable space heaters have an element of danger. That is, by effectively doing their job, they have the potential to cause burns.

But many, maybe even most, of the fire and burn-related accidents associated with space heaters can be attributed to unwise or errant behavior on the part of space heater users: Draping clothing or wet towels over the heater for drying, plugging a heater into an old, frayed or long extension cord or into an overburdened outlet; accidentally tipping over heating units; leaving heaters that are hot to the touch within reach of small children, to name just a few examples.

“Space heaters, when used properly, are not considered inherently dangerous,” Jennifer Mieth, a public information officer with the state Department of Fire Services, recently told MassLandlords, “but they are so easy to use incorrectly.”

And like other heavy load home appliances, space heaters also carry the potential of causing shocks and overloading circuits.

“That is a concern for landlords,” said Mieth. “Have they maintained their electrical systems such that tenants can use them safely and properly? Are there outlets that match the amps that a space heater draws?’”

Still, as Mieth points out, when used properly, abiding by all manufacturer recommendations and safety tips included with the purchase of today’s space heaters, they are not anymore inherently dangerous than those other home products that have been known to catch or cause fire and burns: your toaster, electric blanket, air conditioner, clothes dryer, stove, microwave, etcetera.

One facet that partly distinguishes space heaters from some other appliances, however, is their portability. That allows users to potentially place them in precarious locations, such as near curtains (where electrical outlets are often nearby), amid kids’ pathways, too close to a playpen, or atop furniture or shelves where they could topple.

Space heaters should always be used with caution and adherence to recommended safety practices: plug them only into three-prong outlets directly and do not plug any other electrical devices into that outlet; make sure to place them at least three feet away from furniture, curtains or other items; never leave them on and unattended – always turn them off when leaving the room or going to sleep; place them away from high traffic pathways; place them on level, flat surfaces only, never on furniture, shelves or tables; always unplug and store the heater when it is not in use.

Are space heaters dangerous? Certainly, potentially. But they are not the leading cause of home fires, and are not exorbitantly more dangerous than other heat-generating items in your home that also require caution and care.

Before giving your renters permission to use space heaters in their residences, be certain that they have demonstrated themselves to be conscientious caretakers of your property. Even then, have an in-person conversation about space heater use first, explaining the dangers of inappropriate use. Help your renters identify safe locations and electrical connections, and discuss proper procedures.

Do Space Heaters Save Money?

Space heaters can save money. But because there are so many choices of types, brands and features, your space heater purchase has to be made according to the specifics of your situation in order to realize savings.

Space heaters are not expensive to purchase. They range from less than $30 for a small under-the-desk unit up to $200 or more for room-warming heaters. Once you buy a heater, it’s the increased electric bill that mostly accounts for the cost.

Electric infrared space heaters tend to have lower purchase price tags than convection models. However, electric heaters use a lot of electricity, 1,500 watts per hour on average.

Oil-filled electric heaters are considered the most efficient type because they don’t require a constant electric feed; the radiation of the heated oil continues uninterrupted while electricity cycles on and off.

Regardless of type, if you or your renters opt to run an electric space heater throughout winter, you should offset that high cost by lowering the furnace-generated heat through other parts of the house and only warming a single room.

Using a space heater with a built-in thermostat can also help save costs by setting it to turn off when it reaches a set temperature to avoid wastefully over-heating the room. Of course, the lower you set the heater’s thermostat, the less you will pay for electricity to run it.

The size of the heated room will also determine how much you can save using an electric space heater. Those who heat homes with natural gas furnaces can reduce overall heating bills if the heat needed from a space heater is less than half of the total heat for your entire house, according to Consumer Reports.

For best efficiency, run space heaters in rooms that are well insulated or have interior walls. Thin, poorly insulated walls will defeat the purpose of the heater and cost much more by leaking air straight out of the room. You’re essentially heating the outside or cold, unused rooms.

Finally, for the environmentally conscious: electric heating is not only expensive, it also has a heavy carbon footprint. The more efficient your heater is, the better matched it is to your needs, and the more you are able to retain the heated air inside the room, the smaller your environmental impact will be. You also have the option to choose your electricity supply to come from 100 percent renewable energy.

What Types of Space Heaters Are Best?

Foremost, the best heaters are the safest heaters. Today’s models come with a host of safety features that should be considered mandatory: adjustable thermostats that can set the machine to maintain a reasonable temperature; automatic shut-off triggers to shut it down when the internal temperature gets excessive; timer switches that you can set to shut off the heater after you’ve fallen asleep or left the room; and automatic tip-over shut-off switches, essential with kids or pets around.

Importantly, emphasized Mieth, only buy space heaters with an Underwriters Laboratories (UL) certification. This means the machines have been tested for safety and quality by this trusted nonprofit agency. A clearly visible UL emblem is affixed to these models.

Beyond safety, you should match your space heater purchase specifically to your needs. If it’s a small area being heated for one or two people, a small electric infrared heater with a fan can quickly supply direct, sustained warmth.

If you want to heat a full room with several people, consider a large convection heater that circulates heated air throughout the space rather than a radiant heater’s direct beam.

Electric Infrared Heaters vs. Electric Oil-Filled Heaters

Both these types of heaters come with specific benefits and drawbacks. As stated, electric infrared heaters are expensive to run, especially if not well matched to heating needs. But they tend to be among the least expensive to buy, and many prefer these types for their concentrated scope of heat that warms the skin and clothing the minute it’s turned on.

Quickly gaining in popularity is the electric oil-filled heater, or radiator. These models, which look like mini-radiators on wheels, are slightly more expensive than electric infrared heaters but may be the smarter buy in the long run for their superior efficiency.

Electric oil-filled heaters take a little longer to warm up a room because their electric element heats up a reservoir of oil then gradually spreads the resulting warmth throughout the space. These heaters are more effective for heating an entire room rather than a specific smaller space.

Electric oil-filled heaters are also safer than their infrared counterparts because they operate at lower surface temperatures while infrared models heat up their surface housing partly as a way of radiating that heat directly in front of them. Therefore, oil-filled radiators are not as much of a burn threat when touched.

Oil-filled electric heaters also run nearly silently, as opposed to electric infrared heaters, which often use a fan to push the warm air into the room.

Space Heaters in Rentals

Portable space heaters of all types have inundated the consumer market because they are a potentially inexpensive way to provide comfort and warmth to specific, limited spaces within single rooms of a home. For many, these warming devices can make the difference between being healthy and comfortable or shivering through the winter.

But there is no denying that space heaters can be dangerous. In order to use these warming devices for their intended benefit and mitigate the danger, homeowners and renters must heed manufacturers’ safety tips and recommendations for proper use.

Depending on what happens this year with proposed changes to the state sanitary code, issues around portable space heater use in rentals may soon be irrelevant if they are deemed unsuitable in defining habitable residences and therefore illegal.

Watch MassLandlords for ongoing updates on the state sanitary code.