The temperature will rise in summer. Why is it hotter to turn on the light than not to turn on the light?

Boot power is power consumption, not luminous power.

Light bulbs convert electric energy into heat energy and then into light energy. With the increase of temperature, the heat energy converted into light energy per unit time will increase, so the hotter it is, the brighter it will be.

As the temperature rises, the resistance increases and the power consumption decreases.

Therefore, when the light bulb is just turned on, the luminous power is small, but the power consumption is large, and the luminous efficiency will be low; When the temperature rises to a stable level, the luminous efficiency reaches the highest and the power consumption is rated.

After turning on the light, part of the electric energy is converted into light energy, and the light energy radiation will raise the ambient temperature, and part of it will be converted into heat energy, which is the ambient temperature through heat transfer, so the space temperature will rise after turning on the light.

So turning on the light is hotter than turning off the light.

In the past, incandescent lamps were basically used at home. The working principle of incandescent lamps was to convert electric energy into heat energy. At the moment of turning on the light, the temperature of the filament is low, but the resistance is only about one tenth of that in normal operation, and the power consumed in this process is equivalent to the power of lighting for one minute in just a few seconds, so there is no need to talk about how much electricity is used.

Nowadays, people basically use energy-saving lamps, so it is said that energy-saving lamps cost electricity, because some energy-saving lamps need a high-voltage preheating when starting, and the voltage of the external circuit is constant.

This high-voltage start-up is generally realized by internal circuit.

To sum up, the switch of energy-saving lamps is equivalent to lighting for n hours at a time, some say it is N= 1, and some say it is N= 10. It sounds that there is some truth in this statement. If it is really equivalent to the power consumption of 10 hour, for a 20-watt light bulb, the power consumption at the moment of starting is as high as 720 kilojoules, enough to boil 2 liters of water. Such a large amount of heat is emitted in a very short time,