Condensing boilers meet strict efficiency needs
Darren Finley of Ideal Commercial examines how the innovative features offered by modern commercial condensing boilers simplify the replacement of old inefficient boilers, offering the potential for significant cost and energy savings as well as ensuring existing buildings will be able to meet increasingly stringent efficiency requirements
The most recent amendments to Part L of The Building Regulations will be implemented in April this year, and will impose stricter energy efficiency requirements for all buildings. In the context of the Government's long-term plans,
these amendments are the next in a series of energy reduction steps that are being implemented over the coming years to ensure that the UK achieves a 20 per cent improvement in energy efficiency by 2020 compared to 1990 levels.
This '20-20-20' target is, in itself, a step - albeit a substantial one - in the Government's overall (and legally binding) goal of reaching an 80 per cent reduction in carbon emissions by 2050.
In order to achieve these ambitious targets, there is much talk in the industry about the importance of reducing the carbon emissions of existing buildings. This is not really surprising. The commercial buildings that exist today - a total of 1.8 million according to the Green Building Council - are responsible for around 17 per cent of the country's overall carbon emissions and, importantly, most of them will still exist after 2050. In addition, the provision of heating and hot water for these buildings accounts for about a third of their total energy use. Consequently, improving the energy efficiency of key systems such as heating and hot water within these existing buildings is going to be a key part of the overall plan to reduce the country's carbon emissions in time for the 2020 and 2050 targets.
The impact of heating
There are numerous methods of increasing the energy efficiency of existing buildings. However, boilers are at the heart of most heating systems and the fact that these appliances are responsible for a large proportion of the building's
energy use provides the ideal opportunity for making substantial improvements relatively quickly through boiler replacement. Many commercial buildings in the UK are still being heated by old gas-fired hot water boilers that, even when they were brand new, had very low operating efficiencies compared with today's standards. Coupled with the fact that most of these appliances will be even less efficient today due to wear and tear, as well as poor maintenance in some cases, the result is that a large number of commercial buildings are being heated by boilers
that consume excessive amounts of fossil fuels and, in many instances, are not heating the building effectively.
Modern boiler benefits
The most efficient commercial boilers currently on the market will be able to offer efficiencies of around 110 per cent part load and 97 per cent seasonal efficiency, which equates to substantial energy and cost savings when replacing standard efficiency models. As an example, New Forest Council recently replaced three old floorstanding boilers with five high efficiency condensing wall hung boilers during a plant refurbishment project at Totton Health and Leisure Centre. The installation has saved the Council in excess of £6,000 per year in the leisure centre's running costs, resulting in a greatly reduced payback period that will decrease still further if fuel prices continue to rise. This is just one example of the possible reduction in running costs that can be delivered as a result of boiler replacement.
A precise match
Once a condensing boiler is installed, controls are the most effective method of maximising boiler performance. Modern boiler controls will ensure that demand is being matched precisely at all times to optimise efficiency and maintain a safe and comfortable indoor environment. Controls such as modulating sequencers, room sensors, programmable room thermostats, outside sensors and tank sensors, even though they have different functions, should work together to maximise the efficiency of the boiler.
Alternatively, a 0-10V control input will allow easy integration with an existing BMS and this comes as standard on some commercial condensing boiler models.
As commercial boilers will often be monitored by building services managers on-site, an easy-to-use control panel ensures that any minor issues can be quickly resolved and the boiler operation adjusted to meet requirement.
Ease of installation
As well as being efficient and providing a wide range of control options, modern boilers also offer impressive space-saving benefits as they are far more compact.
Wall hung models can offer the ideal solution and leading manufacturers offer these boiler types in outputs of up to 150kW, expanding the options for larger buildings. Corresponding frame and header kits will allow these boilers to be installed in either back-to-back or in-line cascade formation, resulting in the potential for even greater combined capacities of up to 600kW. Extending the options further if, for instance, an application wants to replace an old floorstanding model with wall-hung boilers, low height frame and header kits are also available from some manufacturers. Wall hung models can also provide a timesaving solution when mounted on a prefabricated floor standing frame. These are essentially 'plug and play' solutions that include a variety of components including individual shunt pumps within each unit, single balance headers, sequence controllers, safety and isolating valves and a drain point - making it quick and easy to install and, in the case of retrofit applications, minimising downtime.
For very large output requirements or for certain types of plant room, floor standing boilers may offer the best solution. Modern floor standing boilers offer much smaller footprints compared with older models and many can fit through a standard doorway.
Some leading manufacturers offer floor standing boilers in modular formation, up to three modules high, covering minimum floor area and offering even higher outputs to meet a variety of demands.
Commercial condensing boilers can also offer another financial perk for businesses if they are part of the Government's Enhanced Capital Allowance (ECA) scheme, as this lets businesses claim a 100 per cent first-year capital allowance on qualifying energy saving appliances. The ECA is applicable only to products listed on the Energy Technology List (ETL) and the commercial condensing boilers on this list will have had to meet stringent energy efficiency criteria. This also makes the ETL an easy reference list for specifiers looking for the UK's top performing appliances.
It is clear that replacing old boilers with modern condensing models offers numerous benefits to building owners, particularly in terms of energy savings and reduced running costs. In addition, these benefits can be delivered relatively
quickly due to short payback periods resulting from higher efficiencies, improved controls, easier and quicker installation times and from incentive schemes such as the ECA. Leading manufacturers now offer a wide range of condensing boiler solutions to the growing demand in the refurbishment sector, and it is evident that an emphasis on replacing old inefficient plant with the latest models will play a key role in the UK's race to meet its carbon reduction goals, as well as delivering financial savings to building owners in the short term.
// The author is the national sales director at Ideal Commercial //
10 March 2014