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Sheet Metal Ductwork: Three Considerations for Insulation Selection

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There are different types of ducts designed to service the HVAC system in buildings. One of the most ideal options to consider installing in your building is sheet metal ductwork. In general, these ducts are made from aluminium or galvanised sheet metal, so they are strong and durable. Moreover, the surfaces of these ductwork tubes are non-porous. This means that they are not vulnerable to moisture damage or fungal growths like alternatives.

On the other hand, sheet metal ducts are vulnerable to energy inefficiencies because the walls promote heat exchange. In simple terms, when hot or cool air is conveyed through these tubes, it will lose or gain heat respectively. Therefore, if you would like to promote better long-term performance, you should ensure that the ducts are well-insulated. Here are important factors to evaluate before purchasing and installing insulation for your new sheet metal ducts.

Type of Material

The range of insulation materials suited for use in sheet metal ductwork is relatively limited. However, there are still good options to consider for your project. Fibreglass is the most popular choice for both residential and commercial applications because the material performs well and is economical. If you decide to install fibreglass insulation, you must choose between flexible and rigid products. Flexible insulation products are sold in rolls that can be easily wrapped around any duct.

On the other hand, rigid insulation is not easy to manipulate and roll around tubing. However, it can be cut into appropriate pieces and fitted over rectangular ducts. Mineral wool is a great alternative to fibreglass. This product is available in both blanket and batt forms that are easy to install. In addition, the high density of mineral wool makes the material less prone to convectional heat loss. You should inquire about proprietary insulation materials from your contractor.

Thermal Resistance

Insulation products can perform differently with regard to thermal resistance even when they are manufactured from the same material. Therefore, you must check the R-value of your preferred product before purchase and installation. Basically, this refers to the measure of the pertinent insulating material to resist heat exchange. You should note that higher R-values mean more thermal resistance, but the cost will be higher.

Moisture Barrier

Finally, you should check the insulation for moisture barrier features. This is essential because the nature of insulation materials makes the structure vulnerable to accelerated degradation. The standard barrier for these products is foil or vinyl backing. However, you can also choose insulation with radiant barriers, which also enhances thermal resistance.