what is temperature load and how it should be calculated?

Answer 1

Maybe you're referring to the heat load, say of a cooling system? To predict the maximum heat load of a house you need to know its heat inflow from ambient temperature and sunlight. These would be based on knowledge of the sun's maximum elevation, maximum summer temperature, and house heat characteristics such as radiant absorption, insolated area, total area, insulation material and thickness, and type and size of uninsulated areas, and the desired indoor temperature. Or you can just ask someone with a similar house in your location what he/she uses and if it's adequate.