As an architect, specifier or installer you will be constantly receiving product information stating compliance to the various standards within the HVAC sector. Designed to give assurance that products meet specific performance criteria and are fit for purpose, they are used by manufacturers to endorse their products. However, unfortunately not all the claims made in relation to industry standards are as reliable as they may first seem as Louise Harris, UK Brand Manager for Zehnder explains.
There are currently three key standards which cover radiators and convectors (EN442), radiant heating (EN 14037) and radiant cooling (EN 14240). All products within these categories which are sold in the UK should meet the given standard.
EN 442 – Specification for radiators and convectors
This standard certifies the output of all heat emitters for central heating systems. It defines procedures for determining the standard thermal output of heating appliances (radiators and convectors) fed with water or steam at temperatures below 120°C, supplied by a remote heat source.
EN442 is now a mandatory requirement for all radiators sold into the UK as part of the introduction of CE marking in July this year. Therefore all products must be performance tested and their heat output certified by an independently accredited third party.
EN 14037 – Ceiling mounted radiant panels supplied with water at temperature below 120°C
There is only one test chamber in Europe certified to conduct this testing. This is located at the University of Stuttgart in Germany. The test is conducted on a panel that is 3000mm long and 600mm wide, in a free-hanging/open ceiling position.
Any manufacturer who has tested their product will be able to supply you with a BS EN 14037 certificate from the University of Stuttgart stating the output of a 3000mm by 600mm panel. This requirement should form part of any specification to ensure the correct heat outputs are obtained. Conversely, radiant manufacturers using the BS EN 442 radiator test output will be reporting an incorrect output figure.
Please note a standard is currently being developed to express the output of a radiant panel when it is installed in an enclosed ceiling.
EN 14240 – Ventilation for buildings – chilled ceilings
This European Standard specifies test conditions and methods for the determination of the cooling capacity of chilled ceilings and other extended chilled surfaces. The test method applies to all types of surface cooling systems using any medium as energy transport medium. In addition, this standard refers to chilled surfaces and where surfaces are specified this should be taken to include ceiling, wall or floor as appropriate.
The cooling capacity is presented as a function of the temperature difference between the reference room temperature and the mean cooling water temperature.
Product not currently covered
Unfortunately the performance data of some product types are yet to be defined by a specific European standard – these include trench heaters and forced convection and fan assisted radiators. A new standard for trench heaters and fan assisted radiators is currently under development, but as yet there is no set date for introduction. Fan assisted radiators are loosely included within EN442.
The benefits of European Standards
Like all regulatory procedures, industry standards are intended to improve working practices and product/ information. In fact the definition of a European Standard, as stated by the European Commission is: “Standards are documented, voluntary agreements which establish important criteria for products, services and processes. Standards, therefore, help to make sure that products and services are fit for their purpose and are comparable and compatible.”
With this in mind, the issuing of an industry standard will result in a range of benefits for everyone involved in the specification, installation and use of a product. For example, because all the products are tested using the same methodology and procedures the performance figures published by manufacturers will enable a like-for-like comparison of products on the market. This means that installers and specifiers can readily compare and evaluate the different options available to them in order to make an informed decision as to which product best suits their requirements.
What’s more, with an understanding that the methods of assessment, test and declaration of results are the same, they can reliably ensure precision at every stage of the design process, whilst also being confident that there will not be any issues of under performance in operation.
Finally, safe in the knowledge that performance figures are correct they can concentrate their efforts on additional customer requirements such as design, guarantees and price. This enables them to provide a more bespoke service to improve their customer service level and enhance their professional reputation.
Misuse of industry standards
Whilst as described above it is conceivable to assume that performance figures published in accordance with a specific industry standard are reliable data upon which a product can be selected, unfortunately in some instances they may not be entirely accurate.
Where a standard is not yet written for a specific product type, manufacturers may publish figures in reference to an alternative standard. For example, there is currently no specific industry standard for the performance of trench heaters. However some trench heater manufacturers publish output figures in accordance with EN 442. Because EN 442 is specific to radiators it does not take into account the fact that trench heaters are installed within the floor. Products are therefore tested as free standing radiators, giving much higher and unrealistic output figures, and consequently a false declaration of performance.
Alternatively output figures may be published in reference to a standard which is not yet fully compliant, but is still in draft format. This information can be misleading as by quoting a genuine standard number, albeit it a draft one, the expectation is that the standard is compliant and that the product is meeting a given set of performance criteria. If you are ever in doubt of a standard’s status always check with the British Standards Institute for confirmation.
When used correctly performance figures issued in accordance with a given industry standards are a reliable and trustworthy source of information which will ensure an appropriate specification. However when incorrect information is used it is the customer, the specifier and the installer who suffer the consequences. Over inflated performance figures will generally lead to under performance in operation which in turn leaves the customer unsatisfied. This can result in costly call backs, along with a damaged professional reputation.
Avoiding these pitfalls is quite simple and can be carried out quickly and simply from your desk. Firstly make sure you keep up to date with the relevant industry standards and ensure you are specifying the right product for the job.
Secondly, and perhaps more importantly, remember that manufacturers are there to help. Do not be afraid to question a manufacturer on their testing methodologies or published figures. Fully compliant manufacturers will readily talk through their procedures to assure you of their performance data and will be able to supply support documentation.
Don’t forget, industry standards are designed to be your friend, so manage them correctly and make them work positi
vely for you.