Roundup · Desk
Almost everything sold as a “desk heater” is a 1,500 W room heater in a small box. At a desk that is the wrong tool, and the arithmetic says so plainly.
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A desk needs a personal heater, not a room heater. An under-desk radiant panel draws about 170 W and 1.4 A, warming your legs directly. A typical “desk heater” is 1,500 W and 12.5 A — nine times the power and nine times the running cost, to heat a room you are not trying to heat.
Search for a desk heater and nearly everything returned is a 1,500 W ceramic unit in a small enclosure. It is small, so it reads as a desk product. It is not: it is a room heater that happens to fit on a desk, and at a desk that distinction costs you on two separate axes.
| Under-desk radiant panel | Typical “desk” ceramic heater | |
|---|---|---|
| Rated power | 170 W | 1,500 W |
| Current draw at 120 V | 1.4 A | 12.5 A |
| Share of a 15 A circuit's 12 A continuous allowance | 12% | 104% — over on its own |
| Cost per hour at 18.34¢/kWh | 3.1¢ | 27.5¢ |
| What it heats | You | The room |
| Works in an enclosed footwell | Yes — designed for it | No — blocked airflow |
Draw computed as watts ÷ 120 V; cost as kW × hours × rate at 18.34¢/kWh (EIA, June 2026). The panel column uses the published 170 W of our top pick; the second pick is 150 W, which is 1.25 A and 2.8¢ an hour.
The current row is the one that bites first. A desk is rarely a circuit on its own — it is a computer, two monitors, a dock, a phone charger and, in an office, a printer. Electrical code allows a 15 A branch circuit 12 A of continuous load, and a 1,500 W heater is 12.5 A of that by itself. Add the desk and you are over before anything unusual happens. The panel's 1.4 A is, by comparison, a rounding error. The full circuit arithmetic.
Marley Engineered Products publishes, for its QMark 202SL panel, that it is “energy efficient — costs 1-2 cents per hour to operate”. That specific heater is no longer available (see the FAQ below), but Marley's page is still up, the claim is still on it, and the same claim shape is used across this whole product category — so it is worth checking rather than repeating. The 202SL drew 170 W, the same as our top pick.
| Wattage | Per hour | 1 h | 8 h |
|---|---|---|---|
| 170 W | 3.1¢ | $0.03 | $0.25 |
| 900 W | 16.5¢ | $0.17 | $1.32 |
| 1,500 W | 27.5¢ | $0.28 | $2.20 |
Computed at 18.34¢/kWh — the U.S. residential average for June 2026 (EIA, Electric Power Monthly, Table 5.6.A, released August 26, 2026). Your rate is on your own bill; substitute it and the arithmetic still holds. Figures assume full output for the whole period.
170 W at 18.34¢/kWh is 3.1 cents an hour, not 1-2. For 1-2 cents you would need an electricity rate somewhere around 6-12¢/kWh, which is well below the current U.S. residential average. The claim was probably true when it was written, or is true in a cheap-power state, and it is not true for most American readers today.
That correction does not undermine the product class — 3.1 cents an hour is still about a ninth of what a 1,500 W heater costs, which is the actual argument for buying one. It is just not the number on the box, and you should have the real one. The same arithmetic applies to our 170 W top pick; the 150 W Sengoku below is lower again, at 2.8 cents an hour.
The footwell is the one location in a house where the usual advice inverts. Everywhere else, a fan heater's ability to move air is an advantage — it is how heat gets distributed around a room. Under a desk there is no room to distribute into: it is a small enclosed volume bounded by a desk top, a chair, a computer tower and your legs.
Radiant heat does not need the air. An under-desk panel emits toward your legs and warms them directly, the way sunlight through a window warms your face while the air stays cold. In an enclosed space that is exactly right, and it is why this product category exists as a distinct thing rather than as a smaller version of a room heater. The mechanism in full.
Ranked for fit, not for hype. Coverage and current draw are computed from each unit’s published wattage. Tap a row for the full write-up, or go straight to the listing.
| # | Product | Best for | Covers | Draw | Price |
|---|---|---|---|---|---|
| 1 |  Global Industrial panelFunctionally the same 170 W under-desk panel as the QMark, with the one control the QMark lacks — an adjustable thermostat, so it cycles instead of running until you remember it. | The same panel, with a thermostat | 17 sq ft | 1.4 A | $122.74 · Check on Amazon |
| 2 |  Sengoku SP-160An inch-thick radiant panel that draws 150 W and nothing else — no fan, no noise, no controls to speak of, and about a tenth of the current a room heater pulls. | The cheapest real under-desk panel | 15 sq ft | 1.3 A | $72.54 · Check on Amazon |
| 3 |  Lasko 754201The 900 W low setting is the whole point: it is the rare listing that publishes both settings, so you can compute what the cheap mode actually costs instead of guessing. | One person at one desk | 150 sq ft | 12.5 A | $49.99 · Check on Amazon |
| 4 |  Honeywell HCE220BA shoebox-sized ceramic heater that publishes four preset temperatures and a 2/4/8-hour auto-off — specificity almost nothing else this size offers. | A thermostat with numbers on it, on a small heater | 150 sq ft | 12.5 A | $59.99 · Check on Amazon |
Coverage computed at 10 W/sq ft, average insulation, 8 ft ceiling. Draw computed as watts ÷ volts. Neither figure is a manufacturer claim.
Top pick · The same panel, with a thermostat
Functionally the same 170 W under-desk panel as the QMark, with the one control the QMark lacks — an adjustable thermostat, so it cycles instead of running until you remember it.
| Published specification | |
|---|---|
| Rated power | 170 W at 120 V |
| Controls | Adjustable thermostat |
| Dimensions | 22-7/16" W x 14-14/16" H |
| Mounting | Floor mount, compact under-desk design |
| Finish | White |
| Heat type | Radiant panel |
| Maker’s coverage claim | None published — the coverage figure above is ours |
| Safety listing | No listing mark published in the listing text; check the rating plate for the UL or ETL mark. |
Who it is for
The same desk-bound reader as the QMark, who would rather the panel cycled on a thermostat than stayed on until switched off.
What it is not for
Anyone wanting a room warm. It is a leg warmer with a thermostat, and that is the correct expectation to have of it.
2 · The cheapest real under-desk panel
An inch-thick radiant panel that draws 150 W and nothing else — no fan, no noise, no controls to speak of, and about a tenth of the current a room heater pulls.
| Published specification | |
|---|---|
| Rated power | 150 W at 120 V |
| Element | Radiant panel — no fan, no moving parts |
| Thermostat | Internal, self-regulating; there is no setting to choose |
| Size | 15" x 1" x 21", 3.4 lb |
| Safety | Overheat protection; Sengoku states no hot surfaces |
| Heat type | Radiant panel |
| Maker’s coverage claim | None published — the coverage figure above is ours |
| Safety listing | Sengoku does not publish a UL or ETL mark on its product page or in the manual we could read; check the rating plate on the unit. |
Who it is for
A footwell where the complaint is cold legs, the circuit is already busy, and you want the lowest-draw honest answer rather than a 1,500 W heater in a small box.
What it is not for
Heating a room, or anywhere you need the heater to switch itself off. Without a timer or a set-point it is on until you unplug it, which makes the [unattended-heater guidance](/safety/overnight) matter more, not less.
3 · One person at one desk
The 900 W low setting is the whole point: it is the rare listing that publishes both settings, so you can compute what the cheap mode actually costs instead of guessing.
| Published specification | |
|---|---|
| Rated power | 1,500 W high / 900 W low, at 120 V |
| Thermostat | Adjustable dial; 2 heat settings plus fan-only |
| Size | 9.2 x 7 x 6 in, 2.93 lb |
| Cord | 6 ft (Lasko's published figure) |
| Safety | Tip-over switch, overheat protection, cool-touch housing |
| Warranty | 3 years |
| Heat type | Ceramic (PTC) |
| Maker’s coverage claim | 100 sq ft |
| Safety listing | ETL listed, per Lasko's published specification — one of the few in this roundup that names a mark rather than leaving it to the rating plate. |
Who it is for
A desk, a small office, a dorm room — somewhere you want heat on a person rather than in a room.
What it is not for
A nursery, and not unattended use. It publishes a tip-over switch and overheat protection, but no child lock — and the USFA's advice to switch a heater off when you leave the room applies to every unit on this site, listed or not.
4 · A thermostat with numbers on it, on a small heater
A shoebox-sized ceramic heater that publishes four preset temperatures and a 2/4/8-hour auto-off — specificity almost nothing else this size offers.
| Published specification | |
|---|---|
| Rated power | 1,500 W maximum at 120 V |
| Heat settings | 2 (high and low) |
| Thermostat | Four preset comfort levels — 65°, 70°, 75° and 80°F |
| Auto-off timer | 2, 4 or 8 hours |
| Safety | Tip-over switch; 2x overheat protection (high-temperature sensor plus a thermal cut-off fuse); cool-touch housing |
| Size | 8.5" x 4.5" x 8.86", 2.8 lb |
| Warranty | 3-year limited |
| Heat type | Ceramic (PTC) |
| Maker’s coverage claim | None published — the coverage figure above is ours |
| Safety listing | Honeywell does not publish a UL or ETL mark for this model; it does publish two independent overheat mechanisms. Check the rating plate. |
Who it is for
A small office, a bedside table or a desk, where the heater needs to hold roughly a known temperature and switch itself off after a few hours.
What it is not for
A large or drafty room, and not a nursery — no child lock is published and the presets are reachable by anyone who can reach the unit.
Sources for this entry
Every roundup on this site names something to skip. It costs us nothing to publish and it is the fastest way to tell whether a buying guide was written for you or for its commission.
USB-powered “heaters”
This is arithmetic, not snobbery. A USB-A port supplies 2.5 W on USB 2.0 and 4.5 W on USB 3.0. Even a USB-C PD port negotiating a high profile is not what these gadgets use — they are built for ordinary ports. Set that against the 170 W of a real under-desk panel and you are looking at something in the region of a fiftieth of the output, which is why these things warm a mug and nothing else. There is no wattage at which they become a heater, because the port cannot supply it. If a product's power comes from a laptop's USB socket, it is a hand-warmer, and that is fine — just do not buy it expecting to stop being cold.
A 1,500 W fan heater crammed into the footwell
Two things go wrong at once. Airflow: a footwell is an enclosed cave bounded by a desk, a chair, a computer tower and your legs, and a fan heater needs clear intake and exhaust — blocked airflow is exactly what trips a thermal cutoff, and the repeated cut-and-restart people blame on a faulty unit is usually the unit working correctly. Clearance: the 3-foot rule applies under a desk as much as anywhere, and there is not three feet of anything down there, least of all away from a wastebasket and a tangle of cables. A radiant panel is designed for that space. A tower is designed for an open floor.
Worth saying plainly on a page funded by product links: a heated throw over your legs draws in the region of 100 W and costs roughly 1.8 cents an hour — cheaper again than the panel, and it needs no purchase decision more complicated than a blanket. If you sit still at a desk and your legs are the problem, that is a legitimate answer and we would rather you knew it. The comparison in full.
The panel wins where a blanket does not: you can move, type and stand up without rearranging anything, and it does not have to be draped over you to work. That is a real convenience difference for eight hours a day, and it is the honest reason to spend the money rather than not.
And what we did not do: we have not tested these units, owned them, measured them or run them in a room. Everything above is compiled from published manufacturer specifications and live retail listings, with the electrical load, room coverage and running cost computed by us from the published wattage. The full method.
It is no longer available. We featured it as the top pick here until September 2026, when its listing went permanently unavailable and no live listing for the model could be found anywhere. Marley's own product page for the 202SL Series is still up, which is why the cost-claim correction above still stands. Our current top pick is the Global Industrial panel — the same 170 W, with an adjustable thermostat the QMark did not have.
About 170 W if you want to warm yourself — that is what a purpose-built under-desk radiant panel draws. Most heaters sold for desks are 1,500 W room heaters, which is roughly nine times the power for a job that does not need it.
No. A 170 W panel costs about 3.1 cents an hour at the U.S. average residential rate of 18.34¢/kWh, against 27.5 cents for a 1,500 W heater. An eight-hour working day is about 25 cents rather than $2.20.
A 170 W panel draws 1.4 A and will not. A 1,500 W heater draws 12.5 A, which is more than the 12 A continuous allowance of a 15 A circuit on its own — before your computer, monitors and printer are counted.
Not as heaters. A USB-A port supplies 2.5 W on USB 2.0 and 4.5 W on USB 3.0, a tiny fraction of the 170 W a real under-desk panel uses. They warm hands or a mug; they cannot make you warm.
A radiant panel, yes — that is what it is designed for. A 1,500 W fan heater, no: the enclosed footwell blocks the airflow it needs, which trips its thermal cutoff, and there is no way to keep three feet of clearance under a desk.
Desk-side picks with a low setting, plus the circuit-load problem an office heater creates.
For rooms under 150 sq ft, where 1,500 W is oversized and the thermostat is what actually matters.
12.5 A against a 12 A continuous limit — the arithmetic nobody publishes, and what to do about it.
About 100 W against 1,500 W — when heating the person beats heating the room, and when it does not.
Heating the air versus heating the things in it — the distinction under every other comparison.
Where the 750 / 1000 / 1500 W tiers come from, and why 1500 W is a hard ceiling on a U.S. outlet.