Engineers are under pressure from clients who want to reduce costs wherever possible – which creates a challenge as energy legislation starts to bite, writes Paul Wenden of Fläkt Woods.
Once, when there was a need to move air around, in went a fan attached to anything that would make it rotate.

Soon, we realised that fans did not all have to look the same and that some could be more efficient than others. Fan technology evolved and we started to invent standards.

Then, life became more complicated. We discovered climate change and, realising that most power derives from non-renewable resources, we became concerned about energy efficiency. With growing sophistication, we started designing fan applications with a view to lifecycle costs and long-term energy efficiency.

Lately, things have changed. Until recently, the engineer would create a system to meet a design brief. If there were contradictory requirements - high output, but from a physically small fan - compromises might have been necessary. In addition, the influence of contractors, product suppliers and end users can mean that a specification looks different from the designer's original intention.

The final result, though, should still have been the best fit-for-purpose solution.

There are other factors within the supply chain that influence how an installed system compares with initial design intent. But an overriding desire to deliver what the client wants is, one hopes, all-pervasive.

In simple terms, the HVAC engineer now faces an amended design brief which no longer says: 'Create a system which will deliver the required result, through its lifetime, in the most economic way.' The key phrase 'through its lifetime' is in danger of becoming redundant.






While energy efficiency may be at the top of the engineer's own agenda, they typically have to work to priorities ordered by other people.

Today, severe pressure to cut expenditure means the temptation to achieve an immediate saving is difficult to resist. As a result, today's design brief increasingly says: 'Create a system which will deliver the required result, for the lowest possible implementation cost.'

Major challenge

This creates a challenge when viewed against the legislative background. Among the recent wealth of legislation concerning energy usage, the most significant engineer working with fans is probably Directive 2005/32/EC (the EuP Directive).

The EuP Directive is designed to reduce the energy consumption and environmental impact of energy-using products. With the first phase of implementation under way, it is having a profound impact, not least because the breadth of its scope is way beyond anything that preceded it. In essence, it formally introduces ecodesign to the world of HVAC.

A range of implementing measures will be in force by the end of 2009, imposing specific requirements upon manufacturers or importers of energy-using products (EuPs) for sale within the EU. It identifies seven product groups as, 'offering a high potential for cost-effective reduction of greenhouse gas emissions', concluding with HVAC systems.

Let there be no doubt: this does impact the design of HVAC systems. A key point to the EuP Directive is that it is not limited to final products, but includes components and sub-assemblies.

Anyone designing a system using fans needs to understand the directive. It may not be perfect, but work continues to develop its scope. Its coverage of fans, insufficiently specific, is under review. This is informed by parallel development of an ISO fans standard.

The UK is leading the drive for all-encompassing legislation and standards with the aim that, regardless of type or size, any fan should be covered. It means that requirements and definitions will be driven by how a fan is to be used, not by the fan itself.

This matters. In the fire safety performance arena, for example, fans have a dual role: daily routine use versus emergency smoke clearance. Consequently, loopholes in exiting standards have allowed some manufacturers to avoid certification.

One measure will not easily fit all fans but the FETA standard addressing appropriate use of fans for fire safety was largely successful. And the aim is to replicate this success in the area of energy efficiency.

It is not a question of whether improvements are possible but of when they will arrive. Fan manufacturers need to be ready, as do users and specifiers.

With the EuP Directive, the demand on the system designer can be simple: look for the CE mark on HVAC products.

You should realise, though, that the directive begins with ecodesign, as it makes clear: 'consider the life cycle of the EuP and all its significant environmental aspects'. Energy efficiency is specifically to be considered, from raw material selection through final disposal: every stage of the product's life has to have its environmental impact minimised.

Minimum requirements

The EuP Directive should not be viewed as compulsion but as a guide to the minimum requirements for anyone dealing with fans.

Economic factors are currently a concern for everyone, from global manufacturers to individual contractors. Competitive pressures mean companies are chasing fewer installations. Fan manufacturers should not be alone in asking both central and local government to help in safeguarding our industry.

With fewer commercial projects being implemented, there must be commitment to the such already-defined public-sector projects as Crossrail and the Underground improvements. This should be a nationwide commitment and, where possible, planned projects should be brought forward.

Meanwhile, we can all best help ourselves by remembering the quality basics. Energy efficiency is paramount, but success comes from finding out exactly what the customer wants, then delivering precisely the right solution, within budget and on time.