Energy for heating the air to a specific temperature

In summary, to heat air to a desired temperature in an oven, you need to find out the specific heat of air, the volume of air you want to heat, the thermal conductance of the oven, and the ambient temperature. To keep the air at a given temperature, you will need to supply the same amount of energy as the thermal conductance of the oven.
  • #1
MarianC
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Hi all. I'm trying to find haw much energy is required to get the air heated up to one desire temperature in oven. . I guess the next issue will be haw much energy is required to keep the temperature at the setting point.
A theoretic starting point will be useful from your side, if possible.
Thank you.
 
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  • #2
You need to find out:
  1. The specific heat of air
  2. The volume of the air you want to heat
  3. The thermal conductance of the oven
  4. The ambient temperature
From there on, it's only plugging in numbers in formulas,
 
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  • #3
Thank you for your advice. I will came back after measurements/calculations ( for 1-4 ) for the "data assembly" for the final scope: formulas for energy required.
 
  • #4
I guess, if the calculation are correct :) that we are talking about:

The specific heat of air - 1.026 kJ/(kg K)

The volume of the air you want to heat - 64 m3
The thermal conductance of the oven -
upload_2015-5-29_14-13-59.png

upload_2015-5-29_14-13-31.png

upload_2015-5-29_14-14-28.png

The ambient temperature 40+273K

I will appreciate your further guidance.
Thank you.
 
  • #5
Adding in the specific mass of air ≈ 1kg/m3 gives you 64kg air to heat. Ignoring thermal leakage, this gives 64⋅1.026 kJ/°K from ambient So if you want the oven to reach 200°C, you will need 64⋅1.026⋅160 kJ = 10 506,24 kJ.

Thermal conductance: You have calculated a specific thermal conductance, but we need the inner surface of the oven to get ahead. The thermal conductance for the oven is given in W/°K and you would usually measure it by heating the oven to a given temperature and then turning off the power and measuring the temperature in the oven vs. time.

If your thermal conductance is 1W/°K and you want to keep the oven at 200°C (160°C over ambient), you need to supply 1W/°K⋅160°K = 160W.
 
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  • #6
The heat capacity of the oven might be needed as well as it's thermal conductance.
 
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  • #7
Svein said:
Adding in the specific mass of air ≈ 1kg/m3 gives you 64kg air to heat. Ignoring thermal leakage, this gives 64⋅1.026 kJ/°K from ambient So if you want the oven to reach 200°C, you will need 64⋅1.026⋅160 kJ = 10 506,24 kJ.

Thermal conductance: You have calculated a specific thermal conductance, but we need the inner surface of the oven to get ahead. The thermal conductance for the oven is given in W/°K and you would usually measure it by heating the oven to a given temperature and then turning off the power and measuring the temperature in the oven vs. time.

If your thermal conductance is 1W/°K and you want to keep the oven at 200°C (160°C over ambient), you need to supply 1W/°K⋅160°K = 160W.

Thank's a lot!
I got the idea, I think I can manage from this point.
 

Related to Energy for heating the air to a specific temperature

1. How does heating the air affect energy consumption?

Heating the air requires energy, which can come from various sources such as electricity, gas, or solar power. The amount of energy consumed depends on factors such as the size of the space, insulation, and outside temperature. Generally, the higher the desired temperature, the more energy is needed to heat the air.

2. What is the most efficient way to heat the air to a specific temperature?

The most efficient way to heat the air to a specific temperature depends on the specific circumstances. For example, in a well-insulated space, using a programmable thermostat and properly maintaining heating equipment can help reduce energy consumption. In areas with milder climates, using natural sunlight or passive solar heating can also provide efficient heating.

3. How does the type of heating system impact energy usage for heating the air?

The type of heating system can significantly impact energy usage. For instance, electric heating systems tend to use more energy than gas or solar-powered systems. Additionally, the age and efficiency of the heating system can also affect energy consumption. Regular maintenance and upgrading to more energy-efficient systems can help reduce energy usage.

4. Is it more efficient to heat the air gradually or all at once?

Heating the air gradually can be more energy-efficient than heating it all at once. For instance, turning on the heat an hour before you need it and gradually increasing the temperature can use less energy than turning on the heat to a high temperature all at once. This is because the heating system doesn't have to work as hard to maintain the desired temperature.

5. How can I reduce energy consumption for heating the air in my home or office?

There are several ways to reduce energy consumption for heating the air, including upgrading to a more energy-efficient heating system, improving insulation, using a programmable thermostat, and regularly maintaining heating equipment. Additionally, minimizing air leaks and drafts, keeping curtains and blinds closed at night, and wearing warm clothing indoors can also help reduce energy usage.

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