Armatherm Structural Thermal Bridging Solutions

Transcription

1 Armatherm Structural Thermal Bridging Solutions Minimising energy loss and improving building envelope performance (0) Armatherm is one of the leading suppliers of structural thermal break materials for the construction industry. Our goal is to provide architects, structural engineers and building design professionals with effective solutions to prevent thermal bridging. Typical Thermal Bridging Locations Balcony/Canopy Connection Masonry Shelf Angle Connection Wall Cladding Attachments Foundation to Wall Transition Parapet/Roof Connection Column Base Connection

2 ARMATHERM TM PRODUCTS Armatherm TM FRR Armatherm TM Fabric Reinforced Resin (FRR) Thermal Break Pads deliver high performance thermal insulation between interior and exterior steelwork and / or concrete to prevent thermal bridging. Cutting out thermal bridging stops conduction heat loss and prevents surface condensation from forming inside the building that can be due to cold transfer meeting warm air. Specifications of Armatherm FRR Maximum Loading Pressure N/mm Strain at Maximum Pressure 3% Compressive Modulus N/mm 2 10,000 Shear Strength N/mm Standard Thickness 6mm, 13mm, 200mm, 25mm & 50mm Density Kg/M Thermal Conductivity W/m o K 0.3 Minimum Operating Temp o C 51 Maximum Operating Temp o C 150 Sheet Size Holes 1220mm x 1220mm Washer and Bushing With a bolt through thermal break pad there is the possibility of a slight thermal transfer along the connecting bolt. For the majority of installations this can be ignored, however this effect can be reduced with the addition of Insulation washers and bushing. In extreme applications (e.g. Swimming Pools), to prevent condensation on the bolt head, polyurethane nut cap can be supplied to effectively screen this cold surface from the internal environment. Bolt Size Bushing ID Bushing Detail Bushing OD Bushing Length Bolt Size Washer ID Washer Detail Washer OD Washer Length Note: Bushing and Washers to be supplied at customer s request. Other variations are available. M12 14mm 20mm 10mm M12 14mm 30mm 6mm M16 18mm 24mm 13mm M16 18mm 40mm 6mm M20 22mm 28mm 13mm M20 22mm 47mm 6mm M24 26mm 32mm Armatherm TM mm Reducing heat flow within a building s thermal envelope reduces energy consumption as well as potential condensation issues. Armatherm TM 500 thermal break material significantly reduces energy lost from thermal bridging in building envelope connections. Armatherm TM 500 is a high strength, polyurethane material made in several densities to support a wide range of loading conditions. Due to it s closed cell structure, it does not absorb water or moisture and has limited creep under continuous load. Specifications of Armatherm 500 Grade Compressive Strength N/mm Compressive Modulus N/mm Thermal Conductivity W/m o K R Value Per 25mm M24 Sheet Size Holes 26mm 50mm 6mm 2000mm x 1000mm Minimum Operating Temp o C Maximum Operating Temp o C

3 BALCONY THERMAL BRIDGING SOLUTION The most common interface details for structural framing are canopies and balconies that use cantilevered steel or aluminium elements. These elements are typically connected to slab edges or spandrel beams on the interior side of the thermal envelope passing through insulation and air barrier layers. The R value of a wall assembly can be reduced by as much as 60% due to thermal bridging at balcony and canopy connections. Using a thermal break at these connections will improve the U value of a wall assembly which includes this type of point transmittance. Armatherm TM FRR structural thermal break material is capable of transferring the loading in moment and shear connections without creating significant rotation. In fact, in structural testing, Armatherm TM FRR has been evaluated in moment and shear connections for creep, rotation and any impact on bolt force. While minimising heat flow, the structural performance of these connections must remain acceptable. Balcony/Canopy Connection Balcony/Canopy Connection Continuous Beam 25mm Armatherm FRR using steel bolts 25mm Armatherm FRR using stainless steel bolts 25mm Armatherm FRR using stainless steel bolts and FRR washers and bushings 50mm Armatherm FRR using stainless steel bolts and FRR washers and bushings Exterior Insulation 1D RValue Clear Wall RValue (R o) Uo R effective with Beam R6.9 (1.21) R7.3 (1.28) R8.4 (1.48) R9.2 (1.61) R10.2 (1.79) U effective with Beam (0.83) (0.78) (0.68) (0.62) (0.56) 25mm Point of Beam BTU/hr o F (W/K) 1.73 (0.92) 1.56 (0.83) 1.16 (0.62) 0.95 (0.50) 0.72 (0.38) 10% 33% 45% 58% Balcony/Canopy Connection Thermal Image Bushing & Washers

4 MASONRY SHELF ANGLE BRIDGING SOLUTION Masonry veneer walls require tiebacks and shelf angles which form significant thermal bridges and can reduce a walls R value by as much as 50% making it difficult to meet energy codes. Shelf angles transfer the masonry load back to the buildings structural steel or concrete slab edge interrupting the continuous insulating layer of the wall assembly creating a continuous thermal bridge. To improve the U value of a masonry wall assembly, the shelf angle can be connected to the structure at discreet, evenly spaced points such as plate blades allowing the insulation to pass behind the steel angle, reducing the effects of a continuous thermal bridge. However, building the shelf angle outwards requires larger geometries and additional material to support the cantilevered load. Alternatively, Armatherm TM FRR material can be used directly behind the shelf angle as a thermal break within the insulating layer significantly reducing the linear transmittance of the shelf angle. Rigid, metal flashing used as waterproofing can then be replaced with a nonconductive, selfadhered membrane. Exterior & Cavity Insulation 1D RValue Clear Field RValue (R o ) U o R effective with shelf angle U effective Linear of Shelf Angle BTU/hrft o F (W/mK) Continuous Steel Shelf Angle + R12 + (2.11) R19.8 (3.48) (0.29) R9.9 (1.74) (0.58) (0.544) Steel Shelf Angle with 25mm Armatherm FRR with washer, bushing and S.A.M. + R12 + (2.11) R19.8 (3.48) (0.29) R13.8 (2.43) (0.41) (0.234) 57% Masonry Shelf Angle Connection Bushing & Washers 50mm Masonry Shelf Angle Connection Masonry Shelf Angle Connection Thermal Image

5 WALL CLADDING THERMAL BRIDGING SOLUTION Continuous insulation is almost always compromised by metallic structural connections such as clips and girts which create thermal bridging when connected to steel stud framing. These connections in conjunction with the steel studs have a significant impact on the U value of wall assemblies. Insulation effectiveness can be reduced by as much as 50% due to these heat flow paths. Armatherm z girt improve the U value of cladding and wall panel assemblies by eliminating the use of highly conductive metal girts and aluminum brackets creating wall assemblies that are up to 98% efficient. Armatherm cladding attachments significantly reduce thermal bridging and improve wall assembly thermal performance. Armatherm FRR z girt, clip and structural thermal break materials provide a combination of low thermal conductivity and high compressive strength transferring load and reducing heat loss. The thermal break material is made of a reinforced, thermoset resin that is fire resistant and exhibits very limited creep under load, making it the ideal material for use in structural and façade thermal break connections. Cladding Connection Wall Cladding Attachments Exterior Insulation R Value (RSI) Steel Girts Exterior Insulation Only Assembly effective R Value (RSI) Armatherm Girts Exterior Insulation Only R 10 (1.76) 9.4 (1.65) 13 (2.28) R (2.00) 17.5 (3.07) R 20 (3.50) 13.1 (2.30) 22.2 (3.89) R 25 (4.38) 14.5 (2.54) 27 (4.73) Cladding Connection Thermal Image Depth Flange Thickness 38mm, 63.5mm, 76mm 38mm 3mm Note: Other variations available upon request.

6 FOUNDATION TO WALL TRANSITION THERMAL BRIDGING SOLUTION Thermal Bridging at foundation wall transitions creates heat loss at the foundation perimeter. This reduces the exterior wall's effective R Value. Foundations are part of a buildings thermal envelope. The intersection at a slab on grade to foundation wall and exterior wall to foundation transition are both areas where heat flows out of a building. This is due primarily to noncontinuous insulation details. The linear transmittance (heat loss) at the base of the foundation wall can be reduced by as much as 60% by using an efficient, structural thermal break. Armatherm 500 is a load bearing,thermal break material bearing, manufactured in several densities to provide a range of load capacities with R values as high as R 3.8 per 25mm. Thermal bridging at a foundation wall transition can be reduced further by increasing the length of the slab insulation. Wall to Foundation Transition 50mm Clear Wall RValue (R o ) Slab 1D RValue Slab Heat Loss L2DF Assembly Heat Loss L2DT Linear of Wall to Slab Exterior Wall directly on footing. 25mm fiberboard floor to foundation R10.2 (1.79) R5 (0.88) 1.18 (2.04) (0.534) 50mm Armatherm 500 under exterior wall and interior wall. 25mm fiberboard floor to foundation 50mm Armatherm 500 under exterior wall and interior wall. 50mm Armatherm 500 floor to foundation R10.2 (1.79) R10.2 (1.79) R5 (0.88) R5 (0.88) 1.18 (2.04) 1.18 (2.04) 1.74 (3.01) 1.71 (2.96) (0.294) (0.241) 45% 55% Wall to Foundation Transition Wall to Foundation Transition Thermal Image

7 PARAPET/ROOF PENETRATION THERMAL BRIDGING SOLUTION The roof is part of the building envelope where penetrations such as davits, anchors and supports for dunnage extend through the thermal envelope and roof insulation creating noncontinuous insulation. These interface details are typically connected to interior trusses or structural elements creating a thermal bridge and point transmittance (heat flow). The R value of the roof can be reduced by up to 40% in these areas. A structural thermal break at these locations will improve the U value of the roof assembly and prevent potential condensation problems at the structural connection. Armatherm FRR and 500 series thermal break materials can transfer the loading conditions at these locations while significantly reducing heat flow, creating continuous insulation. The heat loss can be improved by as much as 80%. Roof Screen Post Thermal Modelling Without Thermal Break Parapet/Roof Connection Holes 75mm Roof Screen Post Thermal Modelling With Thermal Break Roof Anchor without Thermal Break Roof Anchor with 12.5mm Armatherm FRR Roof Anchor with 150mm Armatherm 500 Roof Insulation 1D RValue R40 (7.04) R40 (7.04) R40 (7.04) Clear Field RValue (R o ) R42.3 (7.44) R42.3 (7.44) R42.3 (7.44) U o (0.134) (0.134) (0.134) R effective R25.5 (4.49) R27.2 (4.79) R37.2 (6.55) U effective 0.04 (0.223) (0.209) (0.153) Point of Anchor (0.35) (0.3) (0.07) 14% 80%

8 COLUMN BASE THERMAL BRIDGING SOLUTION Internal steel columns traditionally extend through the building envelope floor slab and insulation at their base. In low temperature buildings such as freezer rooms and cold storage facilities, this creates a thermal bridge and point transmittance (heat loss) at the steel column base. This is also the case for exterior columns which support floors or roof overhangs. The column to roof connection interrupts the continuous insulation creating heat loss due to thermal bridging. Armatherm 500, structural thermal break material can support and transfer column loads while providing an effective thermal break at the column connection. With R values as low as R 3.8 per 25mm, Armatherm 500 can help to meet the BS EN requirements for continuous insulation as well as the baseline insulation requirements for floors in refrigerated storage facilities. Column Base Connection Exterior Column to Floor Connection Steel Column without Thermal Break Steel Column with 150mm Armatherm 500 Slab Insulation 1D RValue R30 (5.26) R30 (5.26) Holes Clear Field RValue (R o ) R31.7 (5.57) R31.7 (5.57) U o 0.03 (0.179) 0.03 (0.179) 100mm Exterior Column to Floor Thermal Image R effective R29.9 (5.26) R31.5 (5.55) U effective 0.03 (0.190) 0.03 (0.180) Point of Anchor (0.864) (0.079) 91%