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About heat storage and not about heat conductivity characteristics in materials...


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Posted

Hello.

What is the table I should look for to find which materials have the capability of holding/storing more amount of heat ?  I do not care how fast they conduct the heat if their parameters are related;  and what is it called ?  specific heat ?,  density ?  specific gravity ? , heat conductivity...

Example 1 Kg or iron at 100C or 1 Kg of water at 100C or 1 Kg of concrete at 100C or 1 Kg of wood at 100C...  And does it go by mass, or by volume ?  As in 1 litre of iron, 1 litre of concrete, 1 litre of water instead ...  ?

Posted

The heat capacity, or specific heat capacity

the amount of heat a material must absorb (per unit mass) to raise its temperature by 1K (assuming we’re using SI units)

 

If your interest is the volume of material, modify the specific heat capacity by multiplying by the density

Posted

If you're specifically interested in thermal storage where space is at a premium, then the quantity of interest may be the volumetric heat capacity (typically MJ/m^3/K)

There's a table you can play around with at https://en.wikipedia.org/wiki/Table_of_specific_heat_capacities

Fond memories of playing in front on my grandmother's Rayburn oven predispose me toward cast iron. However, water or high density masonry are probably more cost effective.

Posted (edited)
9 hours ago, Externet said:

I do not care how fast they conduct the heat

Well you should care.

 

Heat capacity is the capacity to absorb heat, yes.

But once absorbed you want to store it and finally retrieve it, not loose it or waste it.

This is where heat conduction and heat transfer coefficients become important.
Thermodynamics forces you to store heat energy at a higher temperature than the surroundings you want to keep warm.
Note this is different from chemical, mechanical potential or electrical energy.
But you want to release it gradually as slowly as needed otherwise much goes to waste.

The design of electric night storage radiators has greatly improved over the years as manufacturers slowly recognised this very important factor.

Seth's cast iron Rayburn was a classic victorian implementation of this knowledge as were the massive cast iron fireplace surrounds they used to install. +1

Edited by studiot
Posted

Thanks gentlemen for your responses.  I have it clear now.  The linked volumetric table suggests water and iron as good simple-to-implement candidates. 

Will then store heat in one of them and set the heat release speed as needed by covering with more or less insulating material.

Posted
5 hours ago, studiot said:

Well you should care.

 

Heat capacity is the capacity to absorb heat, yes.

But once absorbed you want to store it and finally retrieve it, not loose it or waste it.

This is where heat conduction and heat transfer coefficients become important.
Thermodynamics forces you to store heat energy at a higher temperature than the surroundings you want to keep warm.
Note this is different from chemical, mechanical potential or electrical energy.
But you want to release it gradually as slowly as needed otherwise much goes to waste.

The design of electric night storage radiators has greatly improved over the years as manufacturers slowly recognised this very important factor.

Seth's cast iron Rayburn was a classic victorian implementation of this knowledge as were the massive cast iron fireplace surrounds they used to install. +1

I still have those massive iron fireplace surrounds in the upstairs bedrooms in my late Victorian (1897) house. I was surprised to find, when planning some redecoration, that the mantelpieces are all magnetic.

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