Diffusion Offers Quiet Operation with its Highline 235

British heating and cooling equipment specialist Diffusion’s new Highline 235 modular fan coil range is proving the ideal heating and cooling solution for buildings where noise can be an issue.

Noise often tops the list of complaints for hotel guests, but this issue isn’t confined to hotels. Architects and developers of high-end apartments have two main specification requirements when it comes to selecting fan coil units. One is ensuring the best energy efficiency, the other is ensuring that noise levels are extremely low. The Highline 235 delivers solutions to both of these requirements.

The new Highline 235 range of fan coil units boasts exceedingly low sound levels, delivering noise ratings as low as NR25. This ensures its suitability for a wide variety of buildings, particularly residential applications and hotels where quiet operation is critical. Meanwhile, the range’s high efficiency EC motor and fan assemblies provide improved Specific Fan Powers (SFP) as low as 0.14 W/l/s reducing overall building energy consumption, another important consideration for these applications.

“The new Highline 235 range offers quiet, high performance and energy efficient heating and cooling, making it the ideal solution for architects and developers working on hotels and high-end residential applications where low noise and energy efficiency are paramount,” said John Hepper, Technical Director at Diffusion. “The Highline 235 has been designed to enhance efficiency, reduce sound and optimise overall performance to create the perfect indoor environment.”

Developed to create the perfect indoor environment at work and at home, the Highline 235 range of fan coil units offers modular design, compact dimensions and advanced British-made components that deliver low sound levels, reduced energy consumption and optimal performance. Comprising eight models, including 13 fan combinations, the Highline 235 range suits a wide variety of applications that demand the very best performance.

The Highline 235 has also been designed with aesthetics in mind, this makes it an attractive solution for architects designing buildings with an industrial look, as the units can be ceiling exposed, as well as ceiling concealed. Plus, the Highline 235 range provides increased performance due to heat exchangers specifically designed to achieve optimum heating and cooling performance using the industry predominant hot water and chilled water temperatures.

Designed by Diffusion and utilising British made components and excellent build quality, the new Highline 235 range is built to last with a galvanised steel chassis for increased durability. Meanwhile, the Diffusion Highline 235 range’s modular design delivers ultimate flexibility, enabling attenuator and plenum options to be easily configured to suit the application.

Diffusion Offers Quiet Operation with its Highline 235

Design options are almost limitless as the Highline 235 is completely customizable with almost 300,000 configurations allowing customers to choose the fan coil that fits their individual design criteria. This is of particular importance to buildings that undergo a change of use, as the units can be re-configured on-site to suit the new purpose of the building and new configuration, this saves purchasing new models which is very costly and wasteful – a significant sustainability benefit since it lowers the embodied carbon life cycle of the building which is another significant benefit for architects and building owners.

Diffusion has manufactured and supplied fan coil units that operate efficiently in luxury apartments and hotels including De Vere Gardens, Riverlight and One Hyde Park. Specifiers have come to rely on Diffusion’s in-house capability to design the exact fan coil needed for their project and benefit from being able to invite the end user or facilities manager to the Diffusion site to see their product being tested, giving added reassurance that it will outperform the requirements.

All elements of the Highline 235 range have been designed with product performance, ease of installation, and service and maintenance in mind. The condensate drip tray and 22mm diameter drain connection is made from stainless steel for rigidity and longevity, the entire tray can easily be removed on-site for cleaning while the drain connection is located at the lowest position of the condensate drip tray and fitted with a void tray so condensate can drain away easily.

The fan coil range can be supplied with either the Diffusion lifetime ‘Eco’ wire mesh filter, this option provides a robust environmentally conscious solution that can be vacuum cleaned in situ, or alternatively ISO grade media filters. The filter can also be easily removed on-site from either the side of the unit or from beneath the unit. The filters on the larger models are split into two parts, making them easy to remove or clean, this is particularly beneficial when the unit is installed in confined or awkward spaces. Meanwhile, the fan coils are supplied fitted with a controls enclosure which is mounted to the side of the unit for convenience and easy access, this can also be placed away from the unit should this be a requirement for your application.

Forward curved centrifugal fans are used in all models providing the most efficient airflow and acoustic performance. The fan coil units are insulated throughout with class ‘0’fire-rated foam, the thickness of the insulation throughout the unit varies to ensure superior thermal and acoustic performance, 70% of the foam is either 12 or 25mm thick. Diffusion’s new Highline 235 range is compliant with all key performance standards.

Diffusion is a British manufacturer, they have been manufacturing heating and cooling equipment in the UK for over 60 years, during which time it has established an enviable reputation for the quality of product, the bespoke design capability and excellent, personal service. Its competitively priced product portfolio comprises a wide range of fan coil units. Diffusion’s main objective is to design and manufacture high quality solutions to meet clients’ needs, designing and manufacturing energy efficient HEVAC equipment that can accommodate specific requirements in the most cost-effective way, where the standard is never compromised.

The Diffusion team has in excess of 200 years of combined industry knowledge through working closely with customers for over 60 years. This deep understanding of the project requirements has enabled Diffusion to design and manufacture the most advanced, energy efficient products that comply with all relevant Building Regulations.

Diffusion specialises in fan coil design and manufacture and is trusted by countless businesses across the construction supply chain. Diffusion fan coils are in countless landmark buildings including The Shard and The Walkie-Talkie building. Diffusion is a UK manufacturer and continuously searches for new and innovative ways to lower its carbon emissions.

For more information on Diffusion, please visit www.diffusion-group.com.


With over 60 years in the H&V industry Diffusion is one of the oldest most specialist manufacturers of Heating Ventilation and Air Conditioning products in the UK. Over the years Diffusion has been involved with many challenging and prestigious projects across a spectrum of sectors including hotels, commercial offices, retail, schools, hospitals and high end-residential. These projects include: The Shard, The Walkie-Talkie building and One Bishopsgate Plaza, all of these buildings have over 1,000 Diffusion products installed providing the perfect indoor environment for a variety of purposes, ranging from apartments, restaurants, retail outlets and ballrooms to the Shard’s viewing gallery.