Oil Filled Radiator vs Convection Heater: What to Source

You're sourcing heaters for a market that's split between two technologies, and the choice matters more than the wattage rating on the box. Oil filled radiators and convection panels both heat a room, but they do it on different timelines, with different costs, and for different buyers. If you pick wrong, you'll eat returns and chargebacks. Let's settle this now.

The core difference is how they transfer heat

An oil filled radiator heats oil inside a sealed metal fin. The oil holds heat, the metal gets hot, and the heat radiates off the fins. It also creates a mild convection current as air passes over the hot surface. That's why it's called a radiator, even though it's not actually radiating infrared like a quartz element.

A convection heater (wall-mounted panel or baseboard style) pulls cool air from the bottom, passes it over a heating element, and pushes warm air out the top. No oil, no thermal mass. The air warms quickly, but when the element cuts off, the heat stops almost immediately.

That one difference drives everything else.

Warm-up time and comfort: the 10-minute rule

Oil filled radiators are slow. A typical 1500W unit takes 20 to 30 minutes to bring a 12m² bedroom from 15°C to 20°C. Convection panels, same wattage, will do it in about 10 minutes. For a buyer who wants instant warmth, convection wins.

But oil filled radiators keep heating after the thermostat cuts off. The oil stays hot for another 15 to 20 minutes, so the room doesn't swing as much. That matters for overnight use. A convection heater cycles on and off more frequently, which some people find drafty.

For a quiet, steady heat in a bedroom, oil filled is the better product. For a bathroom or office where you want quick warmth on demand, convection is the better call.

Running cost: same wattage, same bill

Here's the blunt truth: for the same wattage, both heaters cost the same to run. 1500W is 1.5 kWh per hour. At $0.15/kWh, that's $0.225 per hour, regardless of technology. The difference is how long the heater runs. Oil filled radiators hold heat, so they may cycle off more often in a well-insulated room. That's where you get an energy efficient electric heater, but it's not magic. It's just thermal mass.

If your buyer is asking for a low wattage electric heater, be careful. A 500W convection panel won't heat a large room. It's fine for a small office or a campervan. For a garage or workshop, you need 1500W or 2000W, and that's going to cost money to run. Don't let them think otherwise.

Weight, mounting, and space

Oil filled radiators are heavy. A typical 11-fin unit weighs 25 to 30 kg. They're portable on castors, but they take floor space and are a pain to ship. Convection panels are light, usually under 5 kg, and mount flush on a wall. That saves floor space and is a huge selling point for small apartments or rooms with limited clearance.

If your buyer is sourcing for a bedroom or a living room, they might want a wall mounted electric heater to free up floor area. That's a convection product, hands down. Oil filled radiators are never wall mounted in practice, unless you want a falling hazard.

Safety and certifications

Both types can be made safe, but they have different risks. Oil filled radiators have a sealed oil circuit, so no exposed elements. They get hot on the surface, but not as hot as a convection panel's outlet grille. Convection panels need good overheat protection and tip-over switches if they're portable.

For bathrooms, you need IP24 rating, which means splash-proof from all directions. Both can be built to IP24, but convection panels are more common because they're thinner and easier to seal. If your buyer is sourcing for bathroom use, make sure the spec sheet clearly shows IP24. Don't sell a non-rated unit into that application.

We build both types at our factory. For oil filled radiators, we use a double-folded steel fin and a hermetic oil seal. For convection panels, we use an aluminum alloy element with a thermal cutout at 85°C. Both get CE and RoHS. If you're selling into the UK, you'll need UKCA as well. Lead time is 30 to 45 days for a standard 1500W oil filled unit, and 15 to 25 days for a convection panel. MOQ is 200 pcs for either.

Real comparison: oil filled vs convection in a 20m² room

Let's put numbers on it. In a 20m² room with average insulation, a 2000W oil filled radiator will take about 40 minutes to raise the temperature from 10°C to 20°C. A 2000W convection panel will do it in 15 minutes. But the oil filled unit will hold that temperature with fewer cycles, so the room feels more even. The convection panel will blow warm air, which feels nice on your face, but the far corner of the room may stay cooler.

For a greenhouse or a workshop, neither is ideal. You want a fan heater that moves air around. But if you're forced to choose, convection is better because it doesn't have a large thermal mass that cools down when the door opens.

What your buyers should ask you

If a private label buyer comes to you asking for the best electric heater with thermostat, ask them where it's going. If it's a bedroom, recommend oil filled. If it's an office or a bathroom, recommend convection. If they want a silent electric heater, both are silent in terms of fan noise, but oil filled radiators make occasional clicking sounds as the metal expands. Convection panels are truly silent, unless they have a fan, which we don't recommend for quiet rooms.

If they want a wifi smart electric heater, either can be fitted with a WiFi module. But convection panels are easier to integrate because they have a simpler control board. We've shipped both with Tuya modules, but the convection line is faster to turn around.

The honest takeaway

Don't let your buyer chase the wrong technology. If they need fast, light, and wall-mounted, go convection. If they need steady, heavy, and floor-standing, go oil filled. Both have a place, but they're not interchangeable. The cheapest product to manufacture isn't always the cheapest to own. Oil filled radiators have a higher material cost and a longer lead time, but they last longer and feel more premium. Convection panels are cheaper to ship and easier to install, but they don't hold heat.

Source accordingly. Your buyers will thank you with repeat orders.