# Heat

Heat is energy transferred due to temperature differences only.

1. Heat transfer can alter system states;
2. Bodies don’t “contain” heat; heat is identified as it comes across system boundaries;
3. The amount of heat needed to go from one state to another is path dependent;
4. Adiabatic processes are ones in which no heat is transferred.

The overall heat loss from a building can be calculated as

H = Ht + Hv + Hi (1)

where

H = overall heat loss

Ht = heat loss due to transmission through walls, windows, doors, floors and more

Hv = heat loss caused by ventilation

Hi = heat loss caused by infiltration

Insulation Thickness, Thermal Conductivity & Performance Criteria

Insulation – Terms, Definitions & Formula