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.

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.

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.

Frame Types

Unlike any of our competitors, we allow you to price all building frame types. Select from Clear-span or Modular rigid-frame buildings. We allow you the full flexibility to choose Gable, Single Sloped or Offset Peak building shape. By far, we offer the widest selection of building and frame types. For options not available through the online system, you will need to request a special quote.

Clear-span Frames - A clear-span rigid frame offers strength and economy. Since no interior supports are necessary, this design is best when you require large areas of clear and uninterrupted space. Factories, warehouses and agricultural buildings are just a few building types that may utilize a clear-span frame building. A clear-span design does have size limitations. As the desired width increases, the frames will become larger and heavier to carry greater loads across the length of the frame. At some point the cost will outweigh the benefit. Even so, clear-span buildings are still effective for buildings as wide as 150' feet and wider in some cases.

Modular Frames - Modular frames use interior columns to evenly distribute the load; reducing the cost of both the frame and foundation of extra wide buildings. The economical advantages become obvious when a building width is about 100' wide or wider. As a result, almost all buildings 100' wide or wider have interior support columns. Modular designs are often used for large factories and warehouses.

Single Slope Frames - Single slope frames have high and low eave heights creating a roof that "slopes" from side to side. To select a single slope design, you specify one eave height and define the roof pitch. Single slope designs are frequently used for strip shopping centers, offices, and RV/Boat storage facilities.

Just about every steel building has at least one framed opening. It is not unusual for buildings to have several openings. Most openings are created for an overhead door, but can be used for the installation of glass fronts or other entries. Most other online sellers offer "field located" framed openings, which require cutting and fabricating on the job site. Metal Building Depot always provides factory-located openings unless your project requires something otherwise.

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.