What Materials Absorb IR The Best?

In summary, for an assignment, the goal is to create a model house and insulate it to conserve heat. The winner will be chosen based on the effectiveness of the insulation, as measured by an infrared thermal camera. The conversation then shifts to the idea of using a material that absorbs infrared radiation to make the house appear colder on the camera. However, it is pointed out that this may be considered cheating and the focus should be on actually improving the insulation. The conversation also discusses the use of reflective materials like aluminum, but it is noted that for a box of air, this would not be as effective as conduction and convection are the main sources of heat loss. The idea of measuring the rate of change of interior temperature is suggested as
  • #1
arc31
For an assignment, we need to make a model house and need to insulate it to conserve heat. The best insulation will be picked as the winner and they are compared with an infrared thermal camera. So I thought if I could absorb the IR, it would look colder on the image therefore seeming like the insulation is better. What materials can be used on the outside to achieve this?
 
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  • #2
Why do you think that absorbing IR would make the house look colder?

Look up "black body spectrum," it may be helpful...
 
  • #3
Isnt that how thermal imaging works? By observing the frequency and amount of IR?
 
  • #4
arc31 said:
Isnt that how thermal imaging works? By observing the frequency and amount of IR?
Where is that IR radiation coming from?
 
  • #5
Aluminium foil for example reflects IR. Otherwise the bodies themselves emit EM waves their frequency dependent on the temperature.
 
  • #6
Since it is the material itself that is emitting depending on its temperature, making it in a material that absorbs IR will not change anything.

There might be some choice of material that will trick the thermometer into giving a false reading, but as a teacher I would consider that cheating.

You should spend your effort in making your model house actually insulated.
 
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Likes arc31
  • #7
arc31 said:
For an assignment, we need to make a model house and need to insulate it to conserve heat. The best insulation will be picked as the winner and they are compared with an infrared thermal camera. So I thought if I could absorb the IR, it would look colder on the image therefore seeming like the insulation is better. What materials can be used on the outside to achieve this?

You are asking for help on cheating. Shame on you.

Leave the lens cap on the IR camera. That will absorb the IR.
 
  • #8
Wouldnt aluminium also help with insulation by reflecting back infrared and therefore reducing heat transfer?
 
  • #9
arc31 said:
Wouldnt aluminium also help with insulation by reflecting back infrared and therefore reducing heat transfer?

That's better focus on better insulation, not something that seems better but isn't.
 
  • #10
arc31 said:
Wouldnt aluminium also help with insulation by reflecting back infrared and therefore reducing heat transfer?
Depends on what the source of heat. What will be inside the house?
 
  • #11
DrClaude said:
Depends on what the source of heat. What will be inside the house?
The house will be moved from warmth to the outside cold.
 
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  • #12
arc31 said:
The house will be moved from warmth to the outside cold.
So you basically have a box of air. In that case, reflective walls won't help, as air doesn't emit much thermal radiation. Most of the heat lost will be due to conduction between the walls and the air inside, and by convection of the air.

By the way, I find the measuring method a bit strange. I think that measuring the rate of change of the interior temperature would have been a better way of figuring out how well insulated the house is.
 
  • #13
I have convection covered by making it airtight and I nevertheless will use the most insulative materials I can get my hands on. Thanks!
 

What Materials Absorb IR The Best?

As a scientist, I am often asked about the materials that are most effective in absorbing infrared (IR) radiation. Here are the top five most frequently asked questions about this topic:

1. Why is it important to know which materials absorb IR the best?

Understanding which materials absorb IR the best is crucial in a variety of fields, including energy production, materials science, and environmental science. It helps us design more efficient solar panels, improve thermal insulation, and monitor greenhouse gas emissions, among other applications.

2. How do we measure a material's ability to absorb IR?

The most common method for measuring a material's IR absorption is through spectrophotometry. This involves shining a beam of IR light through the material and measuring the amount of light absorbed by the material at different wavelengths. The more light that is absorbed, the higher the material's IR absorption capacity.

3. What types of materials are known to absorb IR well?

Generally, materials that have a high molecular weight and contain polar bonds tend to absorb IR radiation more effectively. This includes materials such as water, carbon dioxide, and certain types of plastics and polymers.

4. Do different types of IR radiation affect material absorption?

Yes, there are three main types of IR radiation: near-infrared (NIR), mid-infrared (MIR), and far-infrared (FIR). Each type has a different wavelength and energy, and certain materials may absorb one type better than the others. For example, water and carbon dioxide have strong absorption in the FIR region, while organic compounds tend to absorb better in the MIR region.

5. Can we manipulate a material's IR absorption capacity?

Yes, by altering a material's chemical composition or structure, we can change its ability to absorb IR radiation. For instance, adding functional groups or specific elements to a polymer can increase its IR absorption capacity. Additionally, the thickness and surface properties of a material can also affect its IR absorption.

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