EXPAND YOUR BUSINESS Inside Refl ective Insulation
Refl ective insulation is a smart choice for metal building systems
Insulating metal building systems poses several challenges. Over the years, the use of refl ective insulation has continued to grow, as more and more people realize and understand its value in metal building systems. An effective insulation system must reduce
heat transfer, and keep energy usage and costs down. It also should prevent interior condensation and provide thermal breaks. The insulation must be durable, withstand years of exposure, and maintain its performance and physical properties over time. Finally, the insulation system must be effi cient, af- fordable, cost-effective and easy to install. Metal buildings are, by nature, very thermally
ineffi cient. A natural property of metal is its high conductivity of heat. This means that virtually all heat energy received by metal is easily transferred with almost no thermal resistance. As a result, main- taining desired temperatures in metal buildings is typically diffi cult, ongoing and expensive. Reducing summer interior heat gain is espe-
cially challenging. The sun’s rays can bring the metal exterior to extremely high temperatures. As a result, the metal cladding essentially becomes a radiator, delivering this heat to the inside of the building. Without proper thermal insulation, a metal building’s interior can easily become hotter than the outside air in the summer. Controlling heat loss in cold seasons is equally challenging.
Controlling heat gain/loss Refl ective Insulation provides the best defense against the radiant heat transfer that occurs com- monly in metal building systems. The key is the alu-
minized surfaces, which provide a thermal refl ectiv- ity of 95-97 percent. This high refl ectivity (and low emissivity), results in a surface that interrupts and redirects the fl ow of radiating heat energy. In metal building systems, the vast majority of
heat gain/loss is the result of radiant heat transfer. Traditional fi ber/mass insulation reduces heat trans- fer via conduction and convection, but has almost no effect on radiant transfer. Refl ective insulation is, by far, the most effective defense against radi- ant heat gain/loss in metal buildings.
Preventing interior condensation A secondary benefi t of this thermal performance is reduced interior condensation. In metal buildings, this occurs when water vapor in the air condenses on the ceiling surface. This happens when the air tempera- ture rises until it matches the dew point tempera- ture of the ceiling itself. Since refl ective insulation dramatically reduces interior heat gain, the conditions needed for condensation to form no longer exist. Refl ective insulation typically consists of
highly refl ective aluminized fi lm, laminated to a substrate that provides rigidity, fl exibility, strength and an effective thermal break. Among the most common substrates is a single or double layer of high-strength polyethylene bubble fi lm. The refl ec- tive surface can be on either both sides, or with a white-facing material on one side.
Installing refl ective insulation systems Refl ective insulation can be draped over the purl- ins. When installed with an airspace between the
insulation and the exterior metal, insulation with two refl ective sides can achieve an R-10. Insulation with one refl ective side and one white-facing side, can achieve R-6. It can be attached to the inside of the purl-
ins. This method can provide increased thermal performance, due to the larger enclosed airspace between the refl ective insulation and the metal exterior. This method also covers the purlins, fur- ther reducing the risk of interior condensation. The enclosed airspace between the purlins can also be fi lled with fi ber/mass insulation to meet higher R-value requirements. To achieve the maximum performance, the in-
sulation must always be properly installed, accord- ing to the manufacturer’s specifi cations. Refl ective insulation materials should always be tested under the ASTM 1224 “Standard Specifi cations for Re- fl ective Insulation for Building Applications.”
Kelly Myers is national sales manager of rFOIL Insulation Products at Covertech Fabricating Inc., Shawnee Mission, Kan. For more information, visit
www.covertechfab.com.
is a smart choice for metal building applications.
Why refl ective insulation
• Superior thermal performance against radiant heat transfer: the primary mode of heat gain/loss in any metal building system
• Reduce energy usage and lower heating/cooling costs
• Prevents interior condensation • Lightweight, easy to cut and install • Easy to handle, no harmful fi bers, no itch • Will not harbor mold or mildew • Highly durable and tear-resistant • Will not lose thermal performance over time
• Can be installed over existing fi ber insulation to improve thermal performance, and enhance interior appearance
• Can easily be used to retrofi t existing metal buildings
• Bright interior surfaces can reduce lighting requirements up to 35 percent
• Class 1/A Fire Rating (ASTM E84-09 and ASTM C2599)
This “hybrid” system incorporates fi berglass blanket with rFOIL refl ective bubble-core insulation, installed onto the bot- tom of the purlins. When installed with 6-inch batts (R-19), this combined system increases to R-30. The refl ectivity/low- emissivity of the rFOIL provides the added thermal benefi t of blocking 96 percent of radiant heat transfer, signifi cantly reducing summer heat gain and winter heat loss. The refl ective insulation also provides a clean look by concealing the purlins and improves interior brightness.
38 METAL CONSTRUCTION NEWS November 2013
• Passes NFPA-286 Full Room Burn Test • Passes ASTM G-155 (long-term weatherization/oxidation)
By Kelly Myers
www.metalconstructionnews.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68