Q&A for How to Calculate Heat Capacity

As far as the efficiency goes, the difference in efficiency is not that much between sizes. However, for a two-bedroom unit, you will want a minimum volume of 20 liters in your tank.

Watts and J/KgK measure different things and cannot be "converted" to one another. J/KgK is the heat capacity, which is a property intrinsic to a particular material, while Watt is a unit of power.

It would help you if you wanted to use one of the materials as a radiator, or if you wanted to calculate the temperature of an assembly in different conditions. These are just two examples, but there can be a lot of others.

Use Q = mc* (change in temp) for the liquid state; c = specific heat capacity- 4.2 J/g, m = mass of ice, and Q is the heat required. For the solid state, use same equation, with different specific heat capacity, use that of ice. For the heat required to melt it, use Q = mLf, where Q is heat, m is mass, and Lf is the latent heat of fusion of ice. Add those three values together for the final answer.

Not unless you know the heat capacity of the object and the rise in temperature. Heat supplied = heat capacity/rise in temperature. Heat capacity is = mass of the object or sample • (times) specific heat • rise in temperature. The energy will be in units of joules or calories or BTU.