Best Heating Systems: Dyson Hot + Cool vs Delonghi Dragon 4

Here’s the sentence no one selling heaters puts on the box: a 2 kW electric heater costs exactly the same to run as any other 2 kW electric heater, whatever the badge on the front says.

The efficiency question, answered honestly

An electric resistance heater has nowhere to lose energy to. Whatever it pulls from the socket ends up as heat in the room, near enough, whether that heat comes off a ceramic element behind a fan or a column of warm oil. A machine drawing 2000 W for an hour uses two kilowatt-hours, and your supplier charges the same for those two kilowatt-hours regardless of which brand delivered them.

So when a review calls one of these more economical, what it’s really describing is control, not conversion. A heater that reaches your target temperature and then cuts out properly uses less than one that runs flat out for an hour because its thermostat is crude. That’s also the point of the EU ecodesign rules for local space heaters, Regulation (EU) 2015/1188, which have applied since 1 January 2018 and set minimum requirements around efficiency and temperature control for electric heaters sold here.

Which brings us to the actual difference between these two: what happens to the heat once it’s made.

Dyson Hot + Cool: heat you feel immediately

The Dyson is a fan first and a heater second, and that shapes everything about it. The Air Multiplier loop pushes a continuous stream of air across the room, so you feel the effect within seconds of switching on. Turn the heating off in June and the same machine becomes a cooling fan, which is genuinely useful in a flat with no air conditioning.

Wattage varies by model. Dyson’s Purifier Hot+Cool HP1, for instance, is rated at 2250 W in its UK specification, and the figure for whichever model you’re looking at is printed on its spec sheet. Alongside that you get a digital display, a remote, multiple settings and a sleep timer.

Where it clearly wins is the safety design. Dyson’s heaters have no exposed heating element and no fast-spinning blades, they cut out automatically if tipped over, and they have a child lock. In a flat with small children or an over-curious cat, that’s not a marketing bullet, that’s the reason to buy it.

The downsides are honest ones. It’s a fan, so it makes fan noise, and the moment it switches off the room starts cooling again because nothing is holding the heat.

De’Longhi Dragon 4: heat that stays put

The Dragon 4 is the opposite bet. It’s an oil-filled column rated at 2500 W with three heat settings, adjustable from around 1100 W upwards, which De’Longhi rates for large rooms up to roughly 75 m³. The enlarged fins are there to increase the chimney effect, pulling cool air in at the bottom and pushing warm air out at the top without a fan.

That last detail matters more than it sounds. No fan means near silence, which is why an oil-filled radiator is the one I’d put in a bedroom or a study. It also means no draught blowing dust around, and no rush of hot air drying your eyes out at a desk.

The trade-off is patience. A column of oil takes a while to come up to temperature, so this is a heater you switch on before you need it, not when you’re already cold. In exchange, the mass keeps radiating for a good while after the thermostat cuts the power. There’s anti-frost and overheat protection built in, an Eco setting, castors that actually roll, and UK retailer listings for the TRD41025T model quote a ten-year manufacturer warranty.

Which one for which room

Down here the heating problem isn’t a long winter, it’s a stone-floored flat that holds the cold from a cloudy fortnight in January and won’t let it go. That changes the answer depending on the room.

Living room used in the evening: the Dyson, because you want warmth while you’re in it and nothing afterwards. Its summer role also means it isn’t a machine you store in a cupboard for nine months.

Bedroom or home office: the Dragon 4, every time. Silence wins, and a room you occupy for hours rewards a heater with thermal mass.

A cold corner of a big open room: the Dragon 4, positioned against the coldest external wall rather than in the middle of the floor. A fan heater can’t out-blow that much air volume.

A ceiling fan is the unexpected ally here, incidentally: run in reverse at low speed it pushes the warm layer trapped at ceiling height back down into the room, and my comparison of Hunter and Westinghouse ceiling fans covers which models have that winter mode.

The safety part I’m not skipping

Portable heaters are among the highest-draw appliances most of us plug in, and they deserve a moment of respect.

• Straight into a wall socket. Never an extension lead, never a multi-socket strip shared with other appliances. A 2500 W load on a cheap adaptor is how fires start.
• Nothing draped on it, ever. That includes drying a towel on an oil-filled column, which people do constantly.
• Not in the bathroom. French wiring rules, NF C 15-100, define protection volumes around a bath or shower precisely because of the water. A portable heater trailing a flex across a wet floor has no business in that room. If you want heating in a bathroom, it’s a fixed appliance installed by a qualified electrician.
• Clear space around it. Both makers specify a minimum clearance from curtains and furniture. Check the manual rather than guessing.

Questions worth asking before you buy

Does the Dragon 4 really cost less to run?

Not per kilowatt-hour, no. It can end up costing less over an evening because its thermostat cycles the power off while the oil keeps radiating, so it spends less time actually drawing current. That’s a control effect, not a fuel effect.

Is a 2500 W heater too much for a small room?

No, as long as it’s thermostatically controlled. A higher rating heats a cold room faster and then cuts out. What you shouldn’t do is buy an underpowered heater for a large space, because it will run continuously and never reach the target.

Which is better for someone with allergies or dry sinuses?

The oil-filled radiator, generally, since it doesn’t blow air around. Fan-based heaters circulate whatever dust is in the room, which some people notice within minutes.

Where can I actually buy them?

Both are widely stocked, from Amazon to the big DIY chains and appliance retailers. Compare the model reference rather than the range name, because Dyson and De’Longhi both sell several versions under the same family and the wattage differs between them.