In the modern transport industry, comfort is always considered a top priority. Passenger carrying trains, buses and coaches are all designed with comfort in mind when it comes to the interior. As well as designing comfortable seating arrangements, public transport designers and manufacturers also factor in the importance of maintaining comfortable temperatures for all conditions.

In most public and mass transit vehicles, HVAC units are installed throughout to provide heating or air conditioning for all passengers. Naturally, heating, ventilation and air conditioning units for large vehicles are linked for ease of use and consistency of temperature and air flow. As a result, they can be somewhat noisy, and temperature is more difficult to keep under control. At CB Frost, as preferred converters of BISCO® cellular silicones, we regularly provide HVAC seals for the rail industry and other modes of public transport.

Key properties of HVAC seals

In order for HVAC units on trains, buses and coaches to function effectively and efficiently, proper insulation is vital. HVAC insulation seals must fit certain characteristics, including:

• Excellent sound insulation – HVAC seals must provide a good level of sound insulation to ensure that noise generated by the units are kept at a comfortable level for passengers.
• Excellent temperature resistance – Materials used for HVAC seals must continue to function effectively in both low and high temperatures. As well as external temperatures, seals must also be able to withstand the high or low air temperatures generated by the HVAC units to allow them to provide the appropriate, consistent temperatures.
• Durability – Durability and longevity of sealing materials is essential. HVAC units must be designed for long term and regular use, so seals and gaskets must be suitable for these specifications to ensure the smooth running of heating and air conditioning units.
• Fire safety – Any insulation material used in trains, buses and other forms of public transit must comply with government regulations for fire safety. Rail industry standards include BS6853, the British standard for fire testing and fire safety, as well as EN45545, the European standard for fire safety, which is now mandatory across Europe. Insulation materials must be resistant to fire and help to prevent fire and smoke from spreading.

As specialists in the field of rubber and plastics, with particular expertise in the rail and mass transit sector, the CB Frost team are well placed to advise on the most suitable materials for HVAC seals. We take great pride in our extensive technical knowledge and high quality of customer service, combine with our second to none product range.

Our range of BISCO® cellular silicones for HVAC seals include:

HT800 silicone sponge

HT800 silicone sponge provides an ideal solution for any HVAC sealing requirement. It exhibits fantastic resistance to extreme temperatures and flames, UV light and ozone to provide consistently excellent performance in all environments. HT800’s compact cell structure and unique formulation allows for a much-enhanced sealing performance, resisting the penetration of fine particles and wind-driven rain.

MF775 silicone rubber

MF775 is a solid silicone rubber with a range of properties that are well suited for use in HVAC sealing applications. It boasts a high level of resistance to UV, ozone and extreme temperatures and will not absorb moisture. These characteristics, combined with fire safety compliance, mean that MF775 is well suited for sealing gaps of various sizes in HVAC systems.

BF1000 and BF2000 silicone foam

Both BF1000 and BF2000 are highly compressible silicone foams with excellent compression set and are as a result highly suitable for use in sealing applications. Due to the softness of the material, they exhibit low closure force, so less force is needed to seal HVAC units, whilst still providing excellent protection and insulation. As is essential for all HVAC sealing materials, BF1000 and BF2000 silicone foam withstand extreme temperatures and resist UV light, ozone and flame in all environments.

To discuss your HVAC sealing needs, or for more information on suitable sealing materials, please contact CB Frost today by calling +44 (0)121 773 8494 or leave us a message online.