As the hot season starts to peak, more and more people turn to shades for comfort when they are outdoors. Be it under a large umbrella, a pergola, a stylish canopy, or a humble tree, most of us would enjoy the fresh air on a sunny day in the shade.
But how much cooler is it in the shade compared to being on a surface directly being hit by sunlight? What are the factors affecting the temperature in a shade? Are there ways to optimize your chosen shade solutions?
Let’s solve these peculiar questions and get the best out of every shade we have.
Is It Really Cooler in the Shade than in Direct Sunlight?
The fact of the matter is, the shade doesn’t make temperatures cooler. The temperature under a shade is no different than the temperature in the surrounding environment. But the shade makes us feel cooler because it is blocking the sun’s radiation. Solar radiation can heat up the air 10 to 15 degrees higher. But because the shade obstructs the direct sunlight, you are not absorbing much of the increase in temperature.
The actual temperature in the shade is impacted by the following factors:
- Air Temperature: An increase in air temperature leads to an increase in shade temperature.
- Wind: Wind flow through the shade removes heat and creates a cooling effect.
- Surface Temperatures: The temperature of the surface underneath the shade can influence the shade temperature.
- Angle: A steeper angle for the shaded area can reduce the heat from the surface, maintaining a cooler temperature.
Temperature and Sunlight
In the context of temperature, there is a considerable difference between direct sunlight and shade. Two major factors contribute to these differences, specifically solar radiation and its cooling effects.
Direct Sunlight vs Shade
Direct sunlight refers to the sun’s rays reaching a surface without any obstruction, whereas shade is created when an object, such as a tree, building, or umbrella, blocks the sun’s rays. The temperature in direct sunlight is usually higher because this unobstructed sunlight warms the surfaces it contacts, resulting in a strong increase in temperature.
On the other hand, shade prevents direct contact with the sun’s rays, which in turn leads to a lower temperature when compared to a sunlit area. However, this does not mean that there is no heat in the shade, as the surrounding air and surfaces that were exposed to sunlight may still transfer heat to shaded areas.
Solar radiation is the primary source of heat and energy on Earth. It consists of electromagnetic waves emitted by the sun, including visible light, ultraviolet (UV) radiation, and infrared (IR) radiation. When solar radiation reaches the Earth’s surface, it can be absorbed, reflected, or transmitted depending on the properties of the surface it encounters.
In direct sunlight, surfaces tend to absorb more radiation, causing an increase in their temperature. This absorbed heat is transferred to the surrounding air through conduction, convection, and radiation processes, resulting in an overall warmer environment in sunlit areas.
As for shaded areas, less solar radiation reaches surfaces directly, limiting the amount of heat generated. This leads to a comparatively cooler environment felt by the body, as less heat is available for transfer to the surrounding air.
The cooling effect in shady areas is influenced by various factors:
- Absorption: Surfaces in the shade tend to absorb less solar radiation than those in direct sunlight, so they remain cooler.
- Reflection: Shaded surfaces still receive indirect sunlight, which may be reflected off nearby surfaces. This reflected sunlight contributes to the cooling effect as it contains lower energy levels than direct sunlight.
- Convection: Cooler air in shaded areas tends to circulate and mix with the warmer air from sunlit areas, contributing to an overall cooling effect.
To sum up, the temperature difference between direct sunlight and shade is primarily due to the varying levels of solar radiation absorbed by surfaces, as well as the cooling effects from reflection and air circulation. Ultimately, understanding these factors can help inform decisions about outdoor activities, sun protection, and energy efficiency.
Factors Affecting Shade Temperature
When seeking respite from the heat, shade is often the go-to choice for many. But how much cooler is it in the shade compared to direct sunlight? There are several factors that contribute to the temperature difference between shade and an area in the sun such as the effect of air temperature and wind, as well as surface temperature and angle on shade temperature.
Air Temperature and Wind
A major factor affecting shade temperature is the air temperature. When air temperature increases, shade temperature also rises. However, the presence of wind can significantly impact the perceived temperature. As wind moves through a shaded area, it helps dissipate heat and can create a pleasant, cooling effect.
Surface Temperature and Angle
Another significant factor in determining shade temperature is the temperature of the surface with which the shaded area is in contact. Surfaces such as concrete, asphalt, and brick can absorb heat from sunlight and re-emit that heat into the shade, causing the temperature to increase. The angle of the shade in relation to the surface also impacts the temperature. If the shaded area is at a steep angle, it can help reduce the re-emitted heat, keeping the temperature cooler.
Can a Shade Do Something About the Humidity?
As the information revealed early on, a shade doesn’t actually lower the temperature but just blocks the solar radiation so it prevents you from feeling hotter. But what about humidity? Can a shade makes you feel cooler in humid weather?
No, it does not. High humidity makes us feel uncomfortably hot because the sweat in our body refuses to evaporate in places where the air is already saturated with water vapor. Because the shade only prevents the sun’s radiation from heating you up from above, it has no power to cool you off when the reason is excess moisture in the air. The surface is already hot in a humid climate, so when the warm air rises from the ground, the shade cannot provide protection from it.
Role of Trees and Plants in Cooling
Trees and plants, on the other hand, play a significant role in cooling the environment around them. They contribute to a cooler atmosphere in several ways, mainly through the processes of photosynthesis and transpiration, as well as the presence of stomata and the production of oxygen.
Photosynthesis and Transpiration
Photosynthesis is a process through which plants convert sunlight into energy, absorbing carbon dioxide and releasing oxygen in the process. During this process, plants also evaporate water from their leaves, which cools the surrounding air. This evaporation is known as transpiration.
Transpiration contributes to a cooler microclimate by releasing moisture into the air, creating a more comfortable and cool environment under the shade of trees and plants. Additionally, as the nearby air becomes more humid, it creates a natural barrier that reduces the effect of solar radiation on the ground.
Stomata and Oxygen Production
Stomata are small openings on the surface of leaves that control the exchange of gases between the plant and its environment. They play a crucial role in both photosynthesis and transpiration.
During photosynthesis, trees and plants take in carbon dioxide and release oxygen through their stomata. This increase in oxygen levels not only benefits humans and animals but also contributes to cooling by enhancing the air’s capacity for heat absorption. Moreover, the shade provided by trees and plants reduces surface temperatures, improving overall comfort levels beneath their canopy.
|Role in Cooling
|Provide shade, release oxygen, and aid in transpiration
|Process where plants absorb carbon dioxide and release oxygen, affecting cooling and air quality
|Evaporation of water from plants, which cools the surrounding air
|Small openings on leaves controlling gas exchange and regulating transpiration
|Produced during photosynthesis, enhancing the air’s capacity for heat absorption
Ultimately, trees and plants play a vital role in cooling the environment through photosynthesis, transpiration, the presence of stomata, and oxygen production. These natural mechanisms work in harmony to create a cooler and more comfortable atmosphere in shaded areas.
Shading Solutions for Protection
Utilizing shading solutions is vital to protect oneself from the harmful effects of sunlight while enjoying outdoor activities.
Awnings and Umbrellas
Awnings and umbrellas are efficient ways to provide shade in outdoor spaces. Both options offer a variety of designs, sizes, and materials to suit various needs.
- Awnings: Attached to a building’s exterior, awnings provide a larger shaded area and are ideal for patios or decks. They can be retractable or stationary.
- Umbrellas: Portable and versatile, umbrellas can be placed anywhere and are perfect for individual shade needs, such as beach trips or picnics in the park.
Risk of Skin Cancer
Exposure to ultraviolet (UV) radiation from the sun increases the risk of skin cancer. Awnings and umbrellas can significantly reduce this risk.
|UV Radiation Level
|Risk of Skin Cancer
Shading solutions also help protect against premature aging and other skin damage caused by sun exposure.
In hot weather, shade is essential to maintain a comfortable environment, preventing overheating and heat exhaustion.
Awnings and umbrellas help to lower the ambient temperature in shaded areas, allowing individuals to stay cool and avoid heat-related health issues, such as dehydration or heatstroke.
Overall, implementing shading solutions like awnings and umbrellas protects us from the harmful effects of sunlight, reducing the risk of skin cancer, and improving comfort in hot weather conditions.
Most shades we know are typically over our heads that directly block the sunlight from above. But what about window shades? Window shades are solid window coverings commonly made from soft textiles such as firm cloth or heavy paper. If
In the summer, the purpose of window shades is to protect your home from getting too much sunlight and provide some privacy. Come wintertime, these indoor shades prevent the warmth generated by your heating system to radiate out of the windows, wasting energy unnecessarily.
Despite being indoors, you can still be protected from the harsh sunlight and its radiation if you consider window treatments such as blinds or shades.