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.

Wall Installation

Labels on wall insulation rolls indicate the length as well as the number of pieces that need to be cut from each roll. We recommend that all rolls be cut from a clean location to avoid staining the insulation facing.

1) Cut the dimensions of the insulation from the base angle to eave strut or rake plus 6"-12" extra.

2) Attach one end of the insulation to the base angle using double-faced tape.

3) Pull from the other end to stretch the insulation tightly outside the girts to the eave or rake, and attach with double-faced tape.

4) Make sure the facing is toward the interior of the building and attach the panel to the structure.

5) Install the next roll in the same manner, with edges butted snugly. Then fasten the tabs using one of the methods described.

Before you Buy

Do you know the company you're doing business with? Is the supplier a member of the Better Business Bureau? Do they have a record of dealing honestly? Can they refer you to satisfied customers? Is the physical address to the company available? Can you visit them at their offices? Are they a real company with a history of quality manufacturing? Are they Active Members of the AISC (American Institute of Steel Construction) Do they post any affiliation with any steel building association? Do you know what you are paying for? Does the steel building contract give line-item prices? Will you receive comprehensive set of erection plans? Are you getting written 30-year paint and 25-year Galvalume Plus® warranties? Does the contract specify 26 gauge panels? Does their roof panels include a "purlin bearing" leg? Does the roof system have an Underwriters Laboratories Class 90 rating? Are you being supplied with premium fasteners with a lifetime red-rust warranty? Will your steel building have a sculptured trim package? Are all the clips welded to primary structural components? Are the framed openings factory located? Does the supplier have the ability to engineer a custom design? Will you receive an 80+ page fully illustrated erection manual? Does the supplier have an in-house customer service department? Does the supplier actually manufacture what they sell? Do they process and produce all their drawings in-house? Do they ask you to sign a contract and pay a deposit before you know the total cost?

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.

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.