Why do factories and stores get hot?

basic information

**The Reason Why Shade from Trees is Cool** - Shade from trees is cool because the leaves are heated by the sun, and the moisture inside evaporates, taking away heat from the leaves in the form of latent heat. - The underside of the leaves cools down, so the shade does not emit radiant heat towards the human body, making it feel cool. *The leaves absorb the radiant heat from the human body.* *For more details, please refer to the PDF document or feel free to contact us.*

Price range

Delivery Time

Applications/Examples of results

For more details, please refer to the PDF document or feel free to contact us.

Detailed information

• 

  Why is it that, even though the wind passes through and the temperature remains unchanged, the shade of a corrugated metal roof is hot while the shade of a tree is cool?

• 

  Radiant heat refers to electromagnetic waves such as far infrared rays. When you have a campfire in a drum, your body warms up even though the wind is blowing. In this way, radiant heat moves from the higher temperature area (the drum) to the lower temperature area (the human body), transmitting heat regardless of the air. Radiant heat = electromagnetic waves

• 

  The reason why a folded plate roof is hot and the shade of a tree is cool The shade is cool because the leaves are heated by the sun, and the moisture inside them evaporates as latent heat, drawing heat away from the leaves. As a result, the underside of the leaves cools down, so the shade does not emit radiant heat towards the human body, making it feel cool. *The leaves absorb the radiant heat from the human body. The temperature of a folded plate roof can reach 70°C to 80°C in summer. The skin temperature of the human body is about 32°C to 33°C, so the radiant heat from the folded plate roof is directed towards the body. Thus, even in the same shade, the perceived temperature can vary greatly depending on the presence or absence of radiant heat.

• 

  Principle of Heat: Heat moves from high to low temperatures. The temperature measured by a thermometer (the temperature of the air) has directionality, with higher temperatures at the top and lower temperatures at the bottom. This is because warm air becomes lighter and rises. However, radiant heat, being electromagnetic waves, does not move in a fixed direction like air; it travels in all directions, 360 degrees. Following the principle of heat transfer, it moves from areas of high temperature to areas of low temperature, so the radiant heat from a corrugated roof that reaches over 70°C in summer radiates towards the cooler indoor environment.

• 

  Effect of Thermal Insulation Materials Thermal insulation materials are most effective at preventing "radiant heat," which is transmitted through infrared radiation, one of the three types of heat. It is said that about 75% of summer heat comes from this radiant heat, so preventing radiant heat contributes to heat mitigation. Please watch the video that shows a thermal imaging recording of the temperature rise after a certain period, with insulation and thermal insulation materials installed at the same distance from an electric heater that generates "radiant heat." From this video, it is clear that thermal insulation materials are effective in efficiently preventing the "radiant heat" emitted from the electric heater. (Experiment video is posted above)