Heat Transfer

Effectively controlling temperature in a steel building requires insulation to be present along exterior walls and roof. When a temperature differential is present in an enclosed steel building, heat will work from warmer areas to colder areas until the temperature in the building has stabilized. At the point of thermal stabilization, the cooler (and heavier) air will be present at lower elevations and warmer air will be present at the roofline. The function of insulation is to help stabilize air temperature at more desirable levels. When it is hot outside, preventing heat from transferring into the building is the goal, and of course in the winter we want heat to remain inside.

Heat transfer occurs in three ways:

Conduction : Occurs in a solid or liquid when heat from one object is transferred by touch to another object. An example of this occurs when a pot on a stove will heat up by conductive heat transfer from an electric coil.

Convection : Occurs with the physical movement of air. There are two types of convectional heat movement. The first is natural, where hot air rises displacing the cold air and moving it down. The second type is forced or mechanical convection. This occurs when an object, like a fan, physically moves or "forces" the air to move.

Radiation : Occurs when an object is warmer or hotter than the air around it. For example, the sun, which is hotter than everything around it, radiates heat waves that travel through the air and is either absorbed by or reflected by the surface it comes in contact with.

Thermal Conductivity (K-Value)

A unit used to express the amount of heat, in BTU's per hour, that passes through one square foot of homogeneous material that is exactly one inch thick and has a temperature difference of one degree Fahrenheit between its surfaces. As the K-Value decreases, so does the amount of heat permitted to pass through the material.

Concealed Condensation

Concealed condensation is the most difficult to deal with and can be the most damaging to any kind of structure. This type of condensation may be controlled in metal buildings by the proper ventilation. Additional condensation control can be accomplished by venting the cold cavities of the walls and roof.

Framed Opening Cover Trim

Full cover trim. Provides head and jamb cover trim and sill trim if applicable, so that no red iron is visible at the opening.

Visible Condensation

To effectively control visible condensation, it is necessary to reduce the cold surface areas where condensation may occur. It is also important to minimize the air moisture content within a building through the use of properly designed ventilating systems.