Most panel heaters available on the market are convection-only heaters. That means they warm up a room by heating the air. Typically they have an element that's exposed to the air, which can create that burning dust smell.
Even low-cost oil-filled column heaters produce mostly convection heat because of the shape of the fins.
Convection heat circulates using air currents. Hot air rises to the ceiling, cools and eventually circulates back to the heater. It's easily lost to draughts and open doors, and in general people find it less comfortable.
Purmo panels are true radiators. They produce much more radiant heat. Think of the feeling of the sun on your face, this is an example of radiant heat.
Radiant heat is unaffected by air currents, because it's infrared energy. It behaves in exactly the same way as light, beaming out the front of the radiator and warming objects and people directly.
While convection heat is better at getting around corners and spreading out, radiant heat feels much more comfortable and doesn't escape the room as quickly. You generally need less radiant heat energy to make a room feel comfortable. This can translate to energy savings if you set your thermostat a degree or two lower.
Purmo electric radiators produce a mix of radiant and convection heat, so you get the best both worlds. They're also fully enclosed, so there's no potential for burning dust, and they operate completely silently.
