How to Choose a Space Heater in 2026

Nearly every electric space heater sold in the US lists the same 1,500-watt maximum, so wattage alone won’t tell you which one to buy. The specs that actually separate these three are the heating technology behind that wattage, how the manufacturer defines the room it will heat, and the safety hardware built around the element. This guide walks through what each published spec changes and lays three models - one per price tier - side by side.

Wattage is capped by your outlet, not by the manufacturer

Standard US household circuits run 120 volts at 15 or 20 amps, and UL safety standards keep plug-in space heaters at or under 1,500 watts so a single unit doesn’t overload a shared circuit. That’s why all three heaters here land on exactly 1,500 W (the De’Longhi also offers a 700 W low setting). A higher price does not buy more wattage in this category - it buys a different way of turning that same 1,500 W into room heat.

Heating technology decides how the room warms, and how fast it cools back down

Ceramic and PTC (positive temperature coefficient) elements heat the air directly and respond almost instantly - point one at a cold room and you’ll feel a difference within a minute or two. Oil-filled radiators like the De’Longhi heat a sealed reservoir of diathermic oil, which takes longer to warm up but keeps radiating heat for a while after you switch it off, and runs at a lower surface temperature than an exposed ceramic element. Neither is objectively better; they trade speed for a gentler, longer-lasting warmth.

Coverage area is measured differently depending on the heating type

This is the number that looks the least comparable, and for a real reason. The Lasko states 300 sq ft, the Dreo states a range of 161-269 sq ft, and the De’Longhi states just 23.2 sq ft - despite identical wattage. Convection-style ceramic heaters typically publish a maximum area based on quickly raising the ambient temperature of a room, while oil-filled radiators publish a smaller “working capacity” figure based on maintaining a steady temperature over a long period. Put another way: the De’Longhi’s number describes a heater meant to run for hours in one room, not a quick blast for a large space.

Safety features are close to standardized, but the details still differ

Tip-over shutoff and overheat protection are now close to universal on major-brand electric heaters, so this spec has stopped being a strong differentiator between tiers. Where the three do diverge is in the specifics: Dreo publishes named internal fault codes (P4 for tip-over, FF for overheat) as part of an 8-layer system, while De’Longhi adds a separate thermal cut-off in addition to its safety thermostat. None of this is marketing fluff - a published fault-code system means the manufacturer has documented failure modes, which is worth checking if you plan to run a heater unattended.

Matching the specs to your room

• The room is large or drafty - coverage area is the spec to optimize, and a convection ceramic heater’s larger stated square footage is built for raising ambient temperature quickly.
• Noise matters because it runs near a bed or desk - look specifically for a published decibel figure; only one of the three heaters here states one.
• It stays in one spot all season - an oil-filled radiator’s smaller working-capacity number reflects sustained, steady heat rather than a large one-time blast, and its lower surface temperature matters more the longer it runs.
• It shares a circuit with other appliances - wattage won’t separate these three, since all three sit at the 1,500 W ceiling; check your circuit’s total amperage instead of the heater’s spec sheet.

Frequently asked questions

Why do almost all space heaters list exactly 1,500 watts?

It’s a regulatory and electrical-safety limit, not a manufacturer choice. A standard 120V/15A household circuit can safely carry about 1,800 watts total, and 1,500 W leaves headroom for whatever else is plugged into that circuit. Going higher would require a dedicated higher-amperage circuit, which most home outlets don’t have.

Do all space heaters automatically shut off if they tip over?

Tip-over shutoff is standard on nearly every heater from a major brand today, including all three compared here, but it is not a universal legal requirement in every category of heater, so it’s still worth confirming on the specific spec sheet before buying rather than assuming it.

Why does the oil-filled radiator report a much smaller coverage area than the ceramic heaters at the same wattage?

Because the manufacturers are measuring different things. Ceramic and PTC heaters typically publish a maximum square footage for quickly warming a room’s ambient air, while oil-filled radiators publish a “working capacity” figure for maintaining a steady temperature over continuous use - a more conservative, sustained-use number rather than a peak-output one.