# Heat transfer by radiation and Temperature difference

• FQVBSina_Jesse
In summary, the conversation is about determining the temperature difference required to transfer heat between TH in a refrigeration cycle and the environment on Mars. The heat to be transferred is generated by the human body during physical activities, averaging at 400 W for 8 hours. The atmosphere on Mars is 100 times thinner than Earth. The temperature difference needed depends on the design of the heat dissipating element, the heat transfer mode (which could be radiation or convection), and the environmental conditions. In the real situation, maintaining a safe body temperature would require both heating and cooling as working and environmental conditions change.
FQVBSina_Jesse
Hello all, this is related to a project that I am working on.

It is not directly related to the project but as part of it, I thought it would be a good idea to check the temperature difference that I need to maintain in order to effectively transfer a certain amount of heat between the TH in a refrigeration cycle and the environment.

The heat that I need to transfer is the amount of heat generated by the human body while performing physical activities. The rate is averaged at 400 W. For 8 hours that is a total of 11520 kJ of heat. The environment is on Mars where the atmosphere is 100 times thinner than Earth.

Temperature difference needed depends on the design of the heat dissipating element and nature of the environment .

So what can you tell us about :

The element configuration ?

The heat transfer mode ? You say radiation but could convection also be relevant or even possibly dominant ?

The environmental conditions ?

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In the real situation it would not be a simple case of removing excess body heat .

The need would be to maintain body temperature within safe limits . Heating or cooling might be needed at any time as working and environmental conditions changed .

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## 1. What is heat transfer by radiation?

Heat transfer by radiation is the process in which heat is transferred through electromagnetic waves, without the need for a medium. This means that heat can travel through a vacuum, unlike other forms of heat transfer such as conduction and convection.

## 2. How does heat transfer by radiation occur?

Heat transfer by radiation occurs when an object with a higher temperature emits electromagnetic waves, which are absorbed by an object with a lower temperature. This causes the temperature of the lower object to increase.

## 3. What factors affect heat transfer by radiation?

The amount of heat transferred by radiation depends on the temperature difference between the two objects, the surface area of the objects, and the type of material they are made of. Darker and rougher surfaces tend to absorb and emit more radiation compared to lighter and smoother surfaces.

## 4. How does temperature difference affect heat transfer by radiation?

The greater the temperature difference between two objects, the higher the rate of heat transfer by radiation. This means that the larger the temperature difference, the faster heat will be transferred from the hotter object to the cooler object.

## 5. What are some examples of heat transfer by radiation in daily life?

Some common examples of heat transfer by radiation include feeling the warmth of the sun on your skin, cooking food in a microwave, and using an infrared thermometer to measure temperature. Additionally, heat transfer by radiation is also responsible for the Earth's climate and the warmth we feel from a fire or a heater.

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