Vertical insulation constructions in particular, where cavities can form on the heated sidebetween the object and the insulation, there is an increased risk of heat loss- caused by convection in the insulation. This risk equally applies to finned walls,as an insulation that follows the contours of the object, in which the cavities in the area of the bars are sealed, cannot always be secured. Take the following measures to prevent convection:
Construct vertical barriers at intervals of 16 to 26 feet ( 5 to 8 m ).
Only use insulations with a longitudinal flow resistance of 350 kPa s/m2.
Fitting an aluminum foil between the individual insulation layers and/or on the exterior isrecommended.
Barriers Depending on the temperature or structural requirements,the barrier can be manufactured from sheet metal [ > 0.02" (0.5 mm)] or aluminum foil [= 0.003" (80 um]]. The barrier must be fastened to the object on the heated side and must reach to the cladding on the cold side. Fill interstices with loose stone wool (mineral wool). Where the insulation is constructed in multiple layers,cascade the barriers.
Insulation of the buckstays Buckstays (girders) that are exposed to heat areinsulated and fitted with a casing. Buckstays exposed to heat on a boiler wall: Buckstays that are exposed to cold are generallynot insulated and not cladded.
