I. What is HVAC Sealing?
HVAC sealing constitutes the core supporting process and component system of heating, ventilation, air conditioning (HVAC) systems, which include heating, ventilation, air conditioning, and fresh air purification. Its primary function is to ensure airtightness, thermal insulation, dust and moisture protection at all joints and movement interfaces between components such as air handling units, ducts, dampers, filter housings, and heat exchange equipment. HVAC systems typically feature metal assemblies that experience significant operational vibrations and substantial temperature fluctuations due to thermal cycling, making them prone to issues like air leakage, heat loss, and ingress of dust or moisture. Proper HVAC sealing effectively prevents air leakage, reduces energy consumption, stabilizes indoor temperature and humidity, blocks outdoor dust and odors, mitigates operational resonance noise, and prevents condensation and mold formation within units. It serves as a critical element for ensuring energy-efficient, stable, and long-lasting performance of HVAC systems and is widely applied across various applications including commercial central air conditioning, industrial ventilation, medical cleanroom ventilation, and residential HVAC systems.
II. Specific Applications of Foam Silicone in the HVAC Sector
Silicone sponge gel is the essential elastic sealing material for high-end HVAC applications. With its fine pore structure, excellent temperature stability under both high and low conditions, low permanent deformation under compression, flame retardancy, environmental friendliness, as well as superior vibration and noise reduction properties, it replaces conventional rubber, sponge, and foam materials, meeting the stringent sealing requirements of precision-driven, long-life, and high-cleanliness HVAC systems. Its applications span critical components including air handling units, ducts, dampers, and purification equipment.
In air handling units (AHUs) and clean air supply systems, expanded silicone rubber is primarily used for sealing and cushioning purposes on unit housing doors, access ports, and filter cover plates. Under frequent opening/closing cycles and thermal cycling conditions, this material maintains stable resilience, effectively preventing long-term air leakage. Additionally, it is odorless and low-volatility, meeting the environmental requirements of high-standard purification environments such as hospitals, laboratories, and cleanrooms while preventing secondary indoor air pollution.
In duct and flange sealing applications, foam silicone gaskets are designed for use in gaps between rectangular or circular duct joint flanges. Leveraging their flexibility, they conform to uneven metal surfaces, ensuring a tight air seal that significantly reduces heat and air leakage losses while enhancing HVAC system efficiency. These gaskets meet the long-term operational requirements of large and medium-sized duct systems in commercial buildings and industrial facilities.
In air valve and fan equipment, foamed silicone is used for sealing the blades of airflow control valves and providing sealing and vibration damping between the fan housing and mounting base. This not only reduces resonance noise generated by operational vibrations, achieving effective noise reduction, but also prevents air leakage when the valve is closed, ensuring precise and controllable air pressure in the ventilation system while enhancing temperature regulation and air exchange accuracy in HVAC systems.
Furthermore, foamed silicone can be used for flange sealing in HVAC plate heat exchangers, condensing units, and high-temperature heat pump systems, withstanding harsh operating conditions characterized by prolonged exposure to extreme temperature fluctuations and continuous vibration. It exhibits excellent resistance to aging, hardening, shrinkage, and cracking, offering a service life significantly longer than that of conventional sealing materials. Gas-phase foamed silicone is specifically designed for high-end applications requiring cleanliness, long service life, and superior flame retardancy; while settled foamed silicone is suitable for standard residential HVAC equipment. The thickness, adhesive backing, and die-cut specifications can be flexibly customized according to specific application requirements, meeting the needs of all types of HVAC systems.