Conduction, convection and radiation

Conduction, convection and radiation are three principles of hygrothermics in architecture that describe the ways thermal energy is transmitted between objects. Conduction is described by the coefficent λ, meaning the ease with which heat can go through an object. λ[W/mK]. Thermal resistance (R) is the capacity of the built elements to oppose the transfer of heat. R=d/λ [m²K/W], d=element thickness. Thermal permeability (U) is the capacity of a built element to allow the transfer of heat. U=λ/d [W/m²K]. Convection is described by the superficial (on the surface) exchange of heat (αc,αcv). Resistance to superficial heat exchange Rc=1/αc [m²K/W]. Radiation is described by the radiant thermal flux.