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.

Panel Options

Color or Galvalume - Our online system includes both Galvalume Plus® and SMP Colors. For a small price increase you can add a colored roof. Our standard colored panels consist of a Galvalume® sheet that has been primed and coated with Silicon Modified Polyester (SMP) paint. Both panel types of panel are very tough, and both our Galvalume Plus® warranty and our paint warranty run for 25 and 30 years respectively. The Galvalume Plus® panels cost less, but the painted panels give your steel building a more refined look.

Color and Roof Pitch - When considering color over Galvalume, be sure to take the roof pitch into account. Higher-pitched roofs are more noticeable, but with a low-pitched roof very little of the roof can be seen.

Proper Ventilation of a Building

Proper ventilation in a building can be an effective measure for condensation control. The end use of the building must be the controlling ventilation design parameter, especially above drop ceiling areas. Ventilation system design should be done at the initial building design stage. Use of a design professional is strongly recommended to assure the best possible system.

CONDENSATION CAN BE MINIMIZED THROUGH CONSIDERATION OF CLIMATE, RELATIVE HUMIDITY AND THICKNESS OF INSULATION.

Ridge Vent

Ridge vents come completely assembled for ease of installation. Ridge vents supplied by Metal Building Depot are of a low profile design to provide gravity type ventilation. Because gravity ridge vents are designed to allow free airflow, some penetration of water during blowing rains is to be expected. Standard available finishes for the ridge vents are polar white and galvalume. Other colors may be available at an additional cost. Nominal ridge vent length is 10'-0". Ridge vents are available with 9" and 12" throats. Bird screens are provided as a standard. The ridge vents can be ordered as continuous or single units. Exterior parts are 26 gage painted or galvalume. Interior parts are all made of G90 galvanized steel. The substructure consists of 10 gage saddle straps with interior baffles of 24 gage steel. Lifter arms and damper slides are made of 18 gage steel. Manual operation is through activation of a pull bar which is attached internally to bell cranked type lifter arms connected to the damper with Teflon coated pins through the damper slides. Dampers are spring loaded to remain in the open position until the pull bar is operated and locked in the closed position. Dampers operate in a vertical manner. Each vent is opened by a pull chain that extends approximately 12" below the roof unless noted otherwise on the order documents. Other opening mechanisms are available at an additional cost upon special request. Ridge vents should not be placed closer than 5’-0" to the endwall steel line to allow room to properly flash the building. For example, a 90’-0" long building with ridge vents required the entire length should have no more than (8) units. The ridge vents are available with the following accessories:

Thermal Conductance (C-Value)

A measure of the amount of heat that passes through materials of any thickness.