The candle warmer lamp can seem like just another table lamp, but interesting phenomena occur beneath its shade. Instead of employing a flame that heats and burns the wax, it employs heat energy to melt the wax, thus releasing its fragrance into the room.
Heat transfer, melting point, and evaporation become part of the process. Moreover, the properties of the candle change throughout the process, starting from the moment when it is lit.
In addition, some modern models have been provided with special controls that help regulate the amount of heat produced without having to touch the lamp itself.
Inside the shade is a small halogen bulb, mostly a GU10 fitting in the 25 to 50 watt range, the same kind used in kitchen downlights. Halogen bulbs run hot by design; a large share of their input power leaves as infrared rather than visible light, which is why they were displaced by LEDs for general lighting and why they are exactly right here.
This bulb is mounted just a few inches above the surface of the jar candle and pointed downwards.
The heat of the infrared energy is absorbed by the surface of the wax until it melts. Fragrance oils are dissolved in the wax, and as the wax liquefies and warms, the oils evaporate from the surface at a rate that rises with temperature. The result is a scent that builds over fifteen to thirty minutes and holds steady as long as the bulb is on.
This is the opposite geometry from a burning candle, which melts from a small pool around the wick. Because the warmer heats the whole surface evenly, the jar does not tunnel, and the full diameter of wax is used down to the bottom. In a jar that would otherwise be tossed out because of an excessive wall of leftover wax, the wax can be used up to near completion; the spent wax comes out of the jar intact.
The melt pool on a warmer sits well below the temperature at which wax vapor could ignite. There is no wick to concentrate heat into a flame and no combustion at all, which is why there is no smoke, no soot, and no carbon monoxide.
It is the bulb only that gets heated up inside the shade; the bulb turns off when the lamp is switched off.
The light is directed towards the wax, but the halogen lamp emits light and heat energy; the shade directs the light downward.
The melted wax becomes a small reflective pool with a warm glow over it, which is why the lamps are sold as lighting rather than as appliances. In practice, most owners treat them as a side-table lamp and let the scent come with it.
Since the entire circuit involves resistive bulbs running on the mains supply, it is trivially easy to automate, and the newer designs do exactly that. A smart Wi-Fi candle warmer lamp puts the bulb behind a Wi-Fi dimmer module with a phone app and voice control, so it can run on a schedule, dim to a lower output, and join the same routines as the rest of a smart home: on at sunset, off at bedtime, off when everybody leaves. A dimmable bulb also gives some control over scent throw, since a lower output melts a shallower pool and releases fragrance more slowly.
Math is not difficult here. A 35-watt bulb for four hours is 0.14 kilowatt-hours, which at typical US residential rates is a few cents a night. Bulbs are rated for a couple of thousand hours and are a standard replaceable part.
A warmer does not provide you with the spark of the flame, and the smell is milder than the burning candle. For people who want the ritual of lighting something, that is a loss. For everyone else, it is a bulb, a shade, and a jar of wax doing what a candle does, minus the part that sets off the smoke alarm.
Ans: In a candle warmer lamp, heat is generated by a bulb in order to melt the wax from the top, and the melted fragrance oils are vaporized into the air without burning the wax.
Ans: The presence of a wick and the process of combustion are missing in a candle warmer lamp.
Ans: The fragrance starts developing when the wax is heated, and it takes about 15-30 minutes to detect it, depending on the type of candle and the heat level.
Ans: Not really; it consumes only a small amount of energy because of small power of the bulb that operates for a short period of time.
