Mineralwool Board Insulation Heat Loss and Surface Temperature Chart

Mineral wool industrial board insulation is used as a thermal insulation on hot equipment such as ovens, kilns, boilers, breechings, etc.  Mineral wool is rated to withstand operating temperatures of 1200°F.  Choosing mineral wool as your insulation material is the easy choice, however choosing the correct thickness is more complicated.  This blog post will help you choose what thickness of mineral wool insulation board to install based on the operating temperature of the equipment.

The insulation fire rating chart listed below shows the Heat Loss (HL) and the Surface Temp (ST) for multiple insulation thicknesses across multiple operating temperatures.

Heat Loss: The amount of BTU's lost per hour per square foot. You can calculate savings based on the cost of a BTU and the square footage of the equipment to be insulated. As you can see, any thickness of insulation will drastically reduce the amount of heat loss.

Surface Temperature: This is a very important piece of data as we need to keep in mind the safety of people working around this equipment.  The chart factors the surface temp based on installing metal jacket over the insulation similar to a metal casing.  Most agencies require equipment to be 140°F or less.

Analysis:

1" Thickness: Acceptable for Operating Temps around 200°F.  Any temps higher than that we should consider going with a greater thickness.

2" Thickness: A good thickness for Operating Temps up to around 400°F.

3" Thickness: Should be considered for equipment with Operating Temps ranging between 400°F to 600°F.

4" Thickness: The preferred thickness for Operating Temps ranging between 600°F to 800°F.

For Temperatures greater than 800°F, even at greater thicknesses, mineral wool insulation would not be the product to be installed.  We would look for products with a lower K-value such as ceramic blanket, which may be more suitable for your desired insulation temperature range.