Condensation Control

The condensation process occurs when warmer moist air comes in contact with cold surfaces such as framing members, windows and other thermally conductive accessories, or the colder region within the insulation itself (if moisture has penetrated the vapor retarder). Warm air, having the ability to contain more moisture than cold air, loses that ability when it comes in contact with cooler surfaces or regions. When this happens, excessive moisture in the air is released in the form of condensation. If this moisture collects in the insulation, the insulating value is decreased.

In dealing with condensation, air may be considered to be a mixture of two gases-dry air and water vapor. One thousand cubic feet of air at 75°F can hold up to 1.4 pints of water. At 45°F, it can hold only 0.5 pints.

Relative Humidity is a percentage measurement of the amount of water vapor present in the air in relation to the amount it is capable of holding at that temperature. Therefore, 50% Relative Humidity would mean that the air is carrying only one-half of the total amount of moisture that it could be holding at that particular temperature. Cold outside air is usually much drier than warm inside air. Therefore, you can lower the Relative Humidity by bringing in outside air to mix with and dilute the moist inside air. At 100% Relative Humidity, the air is "saturated."

The temperature at which the air is saturated and can no longer hold additional moisture is called the dew point temperature. Whenever air temperature drops below its dew point, excess moisture will be released in the form of condensation. Condensation problems are most likely to occur in climates where temperatures frequently dip to 35°F or colder over an extended period of time.

Thermal Conductance (C-Value)

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

PUBLIC and CHURCH

Serving the building needs of America's churches, schools and local, state or federal government is a challenge. A church in Tennessee (above) employs a 60-foot clearspan structure with a specially designed hip-roof to accommodate a spacious open sanctuary. Wood and drywall were used to cover the massive steel beams that meet in the center and support the heavy, built-up roof system. Outside, the application of brick gives the feeling of strength and permanence.

Metal Frame

What is a stronger material than metal? Metal frame buildings are nearly indestructible. You can certainly feel safe in even the worst weather in a metal frame structure.

Erecting a metal frame pre engineered building might sound like a difficult project, but despite this perception, it is really not the case. Metal frame structures are cut to precise measurements and a complete set of building plans will aid in the assembly process.

If you need help constructing your metal building, you will incur additional expenses, so be sure to factor construction cost into your budget when purchasing a steel building.

Facings as Vapor Barriers

The main function of facings is to act as a vapor barrier. While a vapor barrier may not necessarily be able to stop the flow of water vapor, it does an excellent job of minimizing the rate and volume of the flow. This prevents moisture from accumulating within the insulation blanket and the structure, which translates into consistent thermal values and lower heating and cooling costs.

Facings intended to serve as vapor barriers should be installed on the inner, heated surface of the insulation, where vapor pressure is the highest. This helps in preventing vapor from reaching the cooler air and condensing.

VAPOR BARRIERS PREVENT VAPOR FROM REACHING COOLER AIR AND CONDENSING.