While installing a condensing boiler can have a major impact on a building's energy efficiency, it's only part of the solution. To achieve maximum benefit, and satisfy increasingly stringent Building Regulations, the application, total system design and controls must also be considered. Peter Binstead, technical director at Ferroli, explains the importance of taking a holistic approach
THE need to cut carbon emissions by creating more energy efficient buildings is an ongoing obligation if we are to address the problem of global warming. As well as saving the planet, there's also the added benefit of saving money by reducing a building's running costs.

This is particularly relevant in the face of escalating energy prices and can make a big difference to a company's profitability. Whereas a 10% saving, for example, on your domestic heating bill may not be that significant, it could amount to thousands of pounds for commercial energy users - so there's a lot at stake, both for the environment and individual companies.

Clearing the confusion

As we all know, UK Building Regulations relating to conservation of fuel and power have been tightened in response to Kyoto and EU Directives. Following the introduction of Part L1 relating to domestic properties in 2005, Part L2, which extends the regulations to non-dwellings, was implemented last April.

The commercial market is, however, more complex than its domestic counterpart and so, nearly one year on, many specifiers and installers operating in this sector are still unclear about what has to be considered in order to comply with Part L2.

They also face the added complication of different requirements for new buildings (covered in Approved Document ADL2A) and for existing buildings (ADL2B). It's not surprising, therefore, that there is some confusion, and so it's up to manufacturers to guide customers.

The bigger picture

Under ADL2A, a gas boiler specified for a new building must have a gross seasonal efficiency of at least 84%; while under ADL2B, the minimum requirement for a new gas boiler connected to an existing system is 80% (rising to 84% with system credits). In most cases, these efficiency levels can only be achieved by a condensing boiler.

However, simply swapping an old technology boiler for one of the latest HE condensing models, may not achieve full compliance in itself.

In both new and refurbishment applications the whole system must be taken into account, because unless all the elements are working together, the energy saving benefits of installing a condensing boiler won't be achieved.

In balancing the heating system the engineer must achieve a system which returns water to the boiler at 50˚C or less in order for the boiler heat exchanger to take heat from the combustion gases at the lowest possible temperature: maximum efficiency is achieved as the flue gases condense.

It's also important to look at the bigger picture and at ways to reduce heat loss and wastage. For example, zone controllers can be set up to avoid heating unoccupied areas, or a building management system can be installed to control building services more effectively.

Improving a building's airtightness can save a huge amount of energy, particularly with reference to ventilation air duct systems.

Furthermore, ensuring the ventilation system has an effective air-to-air heat exchanger which uses the warm extracted air to pre-condition colder incoming air will reduce the heating load on the system and save energy.

Underfloor heating

Commercial specifiers could also consider warm water underfloor heating, which can reduce running costs by 30% compared with radiators - and by even more when matched with a condensing boiler.

Ferroli can offer a complete underfloor heating package, including design, supply, installation and commissioning, for almost any type and size of building, from schools and hospitals to offices and new homes. In addition to greater energy efficiency, underfloor heating also provides a solution for commercial buildings where radiators would take up valuable space.

Renewable energy

Last but not least, renewable energy solutions can be utilised within a system to reduce CO2 emissions - and heating bills. In response to this growing demand Ferroli has recently launched a choice of two solar-assisted hot water solutions, which can be specified for commercial and residential buildings.

For larger users Ferroli solar collector panels pre-heat the water stored in an AquaCyl twin-coil cylinder by a primary heating coil - a high efficiency boiler then tops-up the water temperature via a second coil in the cylinder.

For smaller applications Ferroli's solar collector panels pre-heat the water in a AquaSol cylinder, which then flows through a HE combi for thermal top-up on demand.

In addition to ikts solar technology developments, Ferroli is also investing in biomass boilers. Biomass fuels are more environmentally-friendly than gas or electricity and cheaper to run - both critical considerations for commercial buildings.

Indeed, Ferroli believes renewable technology is set to play an increasingly important role in the bid to create ever-more energy efficient buildings. And although a high efficiency condensing boiler may well be at the heart of any system, maximum performance and control can only be achieved by looking at the design and use of the whole system.


Ferroli T: 08707 282882