Surface Air Film Coefficient (F)

The amount of heat flow in BTU's per square foot per hour between an exposed surface of a material and the adjacent air. It is the measure of the conductance of heat through the air film that clings to all surfaces.

Calculated Thermal Values

Basically it is the reciprocal of the calculated U-Value. By definition it is the summation of all the R-Values for each of the building's components. This method of calculation does not consider the thermal short circuit effect of structural members, fastener population or the compression of the insulation at its structural members. It should also be noted that this type of calculation often indicates heat loss values for building envelopes that are lower than those actually found in the finished structure.

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.

Frame Features

Connection Clips - Specially fabricated clips are designed to securely connect structural components. Many companies supply only blank plates that must be cut, drilled and/or welded to components before assembly can begin. In some cases it may require many hours of work to connect required clips. Metal Building Depot details and supplies each clip and placement to every building manufactured. We factory weld all clips onto rigid frames and guarantee the correct placement of all component connections. Don't waste your time and money attaching clips that should have been factory located.

Structural Bracing - Most buildings under 60' have sufficient diaphragm action or "panel shear" that provides all the bracing needed to stabilize the building. In some cases of high winds, seismic or snow loads may cause more stress than panel shear can handle, so additional reinforcement may be required. In these extreme cases we will employ the use of X bracing to reinforce the frame. In situations where X bracing cannot be used a wind column is an excellent addition to strengthen a vertical rigid frame column. A portal frame is sometimes used in extreme load circumstances. Portal frames are fairly expensive and only necessary in rare circumstances.

Trim and Gutter

The trim on a steel building serves two essential functions, to close transitions and protect the building from the weather. Trim also adds to the appearance of a building. Our sculptured trim gives the building a refined, quality appearance. Trim covers corner and edge areas of a building. For instance, eave trim creates a transition from the roof to the sidewalls and roof to endwalls.

Most metal building companies often supply "box" or generic trim pieces. This trim routinely has to be modified to fit, as it is created as multi-purpose - and does not fit well on standard panels. We fabricate each profile to match the design of your steel building. We do a lot of work in the shop that will save you headaches in the field. We hem all exposed edges of our trim so it installs easily, fits neatly, and looks great for the life of your building. Our trim is easy to install and adds to the look and the integrity of the building.