In recent years, the integration of closed-cell spray foam insulation in residential construction has become increasingly popular due to its high R-value, air-sealing capabilities, and energy efficiency. However, while this insulation material is celebrated for its benefits, it has also brought unintended challenges, particularly concerning the performance of low-voltage wiring systems, such as alarm systems, networking cables, and home automation infrastructure in the years since the 2017 introduction of a new formulation of HFO Closed Cell foams.

HFC (hydrofluorocarbon) and HFO (hydrofluoroolefin) formulations of closed-cell polyurethane foam differ in environmental impact and performance. HFCs have higher global warming potential (GWP) and contribute significantly to climate change. HFOs, on the other hand, are low-GWP alternatives, offering similar insulation performance with a reduced environmental footprint, aligning with modern sustainability standards.

HFC Closed Cell foams typically maxed out at around 250 degrees while HFO formulations can run as hot as 325 degrees during the curing process.

“In my experience, HFO closed cell foam core temperatures reach higher levels than other closed cell foams; therefore, it is critical to pay attention to the surrounding construction materials that may be susceptible to high temperatures, such as low voltage wiring and water pipes. Thinner passes of spray foam should be used around these components to limit internal core temperatures and reduce the risk of damage. Following application best practices is critical for successful applications; therefore, building owners should seek out experienced and knowledgeable spray foam contractors to achieve the best results.”  Robert Naini, Spray Foam Advisor

The Rise of Closed-Cell Foam Insulation in Residential Homes

Closed-cell spray foam insulation is a dense, rigid material that expands on application to fill gaps and form an airtight barrier. Its high R-value measures thermal resistance, making it an excellent choice for homes in Chicago’s harsh climate. Residents and contractors often use it to insulate attics, walls, and crawl spaces, ensuring energy efficiency in both summer and winter.

While closed-cell foam is a game-changer for energy savings, its application can pose risks to low-voltage wiring systems, especially if applied improperly. The foam’s dense and airtight nature creates conditions that can trap heat around electrical and low-voltage wiring, leading to failures and even fire hazards.

How Overheating Affects Low-Voltage Wiring

Low-voltage systems, such as alarm systems, internet cables, and audiovisual wiring, are essential for modern homes. These systems operate at lower electrical currents and are sensitive to environmental conditions. Overheating, often caused by improper application of closed-cell foam, can lead to several issues:

1. Degradation of Insulation on Wires:

Heat trapped around wiring due to the insulating properties of closed-cell foam can cause the plastic or rubber insulation to degrade. Over time, this degradation exposes the wire, increasing the risk of short circuits or system failures.

2. Signal Interference and Data Loss:

Many low-voltage systems, such as Ethernet cables, rely on the integrity of their insulation to maintain proper data transmission. Heat-induced damage can lead to poor signal quality, intermittent connectivity, and total system failure.

3. Failures in Alarm Systems:

Alarm systems, which often have components running continuously, can suffer from thermal overload when installed in areas with poorly ventilated closed-cell foam. This can lead to false alarms, loss of functionality, or total system shutdown. It can be due to foam covering the alarm system’s components or the space housing your alarm system not having proper HVAC supplies.