What’s the Risk of Painting HVAC Insulation Materials?

Traditionally, building design has “hidden” the building components (pipes, ducts, and insulation) behind walls and ceiling panels. As a result, historically, HVAC insulation has simply needed to offer thermal and/or acoustical performance – the outward appearance of the HVAC material and its facing has largely been insignificant if not entirely irrelevant to the application. However, new design trends are creating a space and a need for HVAC insulation materials that not only offer thermal and/or acoustical control, but also, to the extent it is visible, offer outward aesthetic appeal.

As we see more and more buildings embracing open ceilings and exposed duct work and piping, we’ve seen the requirements and needs of the insulation begin to shift as well. No longer does HVAC insulation simply need to provide thermal and acoustical control, it also needs to provide an exposed surface that serves as a design element that enhances the aesthetic appeal of the space. Architects and designers want HVAC insulation materials that work as specified and look good while doing it.

While it may be tempting to simply omit the duct insulation for the sake of maintaining the aesthetic integrity of the design, that can be a costly approach for a number of reasons. First and foremost, your building may not actually meet the code requirements if the ducts are not insulated. Secondly, controlling the temperatures in your duct system is a crucial component to optimizing the energy efficiency of your building. Additionally, uninsulated ducts not only operate substantially less efficiently (leading to more costly energy bills), but they can also be prone to condensation – especially in humid climates. Condensation can lead to mold growth and even damage the structures surrounding the ducts.

Recognizing these drawbacks to omitting the duct insulation, many installers have simply taken to painting the facing or the exposed surface of the duct insulation to ensure it meets the designer’s requirements. While this practice isn’t uncommon, painting the insulation is actually not a practice that most manufacturers recommend or endorse. The reason for this is that HVAC insulating materials used in buildings have to meet specific fire and smoke ratings called Fire Hazard Classification ratings. In HVAC systems, materials need to have a Fire Hazard Classification rating of 25 or less flame spread and 50 or less smoke developed (typically referred to as 25/50). These numbers are established using standardized test methods like ASTM E-84, The Standard Test Method for Surface Burning Characteristics of Building Materials, and UL 723 Standard for Test for Surface Burning Characteristics of Building Materials.

These tests establish a material’s flammability and its capacity to generate smoke in the event of a fire. All of JM’s HVAC insulations meet the 25/50 flame/smoke spread Fire Hazard Classification requirements per ASTM E-84 and UL 723; however,noneof JM’s HVAC insulation materials have undergone this testing with any type of paint on them. As a result, we cannot guarantee that our insulations will still meet the 25/50 flame/smoke requirements after they have been painted – even if that paint itself meets the 25/50 flame/smoke requirements.

Thus, painting the facing or the exposed surface of the HVAC insulation voids the 25/50 Fire Hazard Classification rating the material received from Underwriters Laboratories (UL). Once this Fire Hazard Classification has been voided, the painted insulation may subsequently fail to meet code requirements.

Since painting HVAC insulation is not a viable option to improve insulation aesthetics, JM has created a number of insulating materials for HVAC systems, mechanical rooms, and office spaces (acoustical panels, ceiling tiles, tack-boards, etc.) with outward surfaces designed specifically for aesthetic applications. We’ll be discussing these materials and more in our upcoming webinar, Insulation Systems as a Design Element. On October 9th, Johns Manville’s Sean Reynolds and Mike Cagle will be taking a detailed look at the insulating materials that offer aesthetic value in addition to insulating performance for HVAC systems, mechanical rooms, exposed piping, and office spaces.

Click here to learn more about our upcoming webinar.