Thermal resistance due to convection is the reciprocal of the product of the convective heat transfer coefficient (hm) and the surface area (A) of the object emitting heat. From the equation, the surface area of the object increases and the thermal resistance of convection decreases. The convective heat transfer coefficient (hm) differs depending on the type of convection. The hm values presented here are for both natural convection and for forced convection (laminar and turbulent flow). To decrease the thermal resistance, increase the surface area of the object. For the natural convection, consider the configuration so that the temperature difference is increased, or for the forced convection, increase the air velocity.