What is the difference between EPD and TM65 for a fan coil unit?
An EPD (Environmental Product Declaration) and the TM65 calculation methodology from CIBSE (Chartered Institution of Building Services Engineers) can both be used to assess the environmental impact of a fan coil unit (FCU). However, there are two main differences between them:
- EPD assesses embodied and operational carbon. TM65 only calculates embodied carbon.
- EPD is an independent third-party verified environmental declaration, known as a ‘Type III’. TM65 is a ‘Type II’. This means that the latter document is self-certified by the manufacturer.
The differences are summarised in the table below:
Environmental Assessment Methodology | Embodied Carbon Assessment | Operational Carbon Assessment | Third Party Verified |
EPD | YES | YES | YES |
TM65 | YES | NO | NO |
Why was TM65 created to measure embodied carbon in fan coil units?
Until TM65 was developed, there was no standardised method to evaluate the environmental impact of building services equipment. As well as new developments fan coil units and chilled water cassettes are often installed in existing buildings during refurbishments to replace or upgrade existing FCUs. This adds embodied carbon to the existing building. The pressure to build net-zero carbon, or even absolute zero carbon buildings and drastically reduce the carbon in those already constructed is increasing if we are to stand a chance of achieving the legally binding target under the Paris Agreement to achieve net zero by 2050. Architects, engineers and contractors, as well as building owners, are increasingly focused on the carbon impact of buildings. To support them, manufacturers needed a way to provide the relevant information about their products based on environmental contribution.
In 2021, TM65 ‘Embodied carbon in building services: A calculation methodology’ was published by CIBSE. It provided fan coil manufacturers with a framework to declare the embodied carbon of their products. The result was based on a calculation carried out at one of two levels. The first level is known as ‘basic calculation’ and the second level – using more detailed data – is referred to as a ‘mid-level’ calculation. The latter gives specifiers a more thorough evaluation of the product’s embodied carbon contribution.
What’s the difference between TM65 and EPDs for fan coil units and chilled water cassettes?
Some manufacturers offer EPDs as well as TM65 evaluations for their fan coil units.As EPDs are based on the Life Cycle Analysis (LCA) of a product, they include its operational carbon as well as embodied carbon impact. They provide a more detailed and accurate picture of the environmental impact of a fan coil unit or a chilled water cassette. This allows specifiers for new or existing buildings to directly compare the carbon contribution across one fan coil unit with another, over the whole lifecycle of a building.
Whilst EPDs are an important tool to help specifiers deliver lower-carbon buildings, they also encourage manufacturers to continuously improve. For example, by using low-carbon materials and refining processes to keep reducing embodied carbon. Designing fan coil units that are more energy efficient reduces their operational carbon contribution to the building.
Where to find EPD and TM65 data for fan coil unit specification
Ability by Dimplex has a range of fan coil units and chilled water cassettes available for selection to help specifiers deliver solutions that help reduce carbon impact throughout the lifecycle of the building. We can supply you with TM65 evaluations and we are in the process of making EPDs available across the whole of the product range.
We have a vastly experienced team on hand to help you find the most appropriate fan coil solution design for your project. Please contact us, and we will be happy to help.
Troy Chambers
