Lessons in retrofit lead to energy efficiency
There can be a temptation to underestimate the returns offered by retrofit technologies on energy efficiency investments, warns Chris Meir, of Remeha Commercial. In fact, adopting the appropriate measures could save schools up to £21,500 a year
When budgets are tight, it is important to identify efficiency savings wherever possible. Schools are a case in point. With utility bills continuing to rise due to spiralling fuel prices and education resources already stretched thin, adopting energy efficiency measures is a practical, affordable approach for schools and local authorities seeking to lower utility bills and carbon emissions and free up funds for the benefit of their students.
In its work with 3,000 schools over a 10-year period, the Carbon Trust identified that schools could save up to £21,500 a year in energy bills by improving their energy efficiency and cutting energy use - that's the equivalent of the salary of a newly qualified teacher. And with heating accounting for on average 58 per cent of a school's total energy use, it makes sense for this to be the first step towards improved energy efficiency.
The UK has a high proportion of old school buildings with old heating systems in place. This means that often the only logistical solution to cutting energy consumption from heating is through retrofitting a modern condensing or super condensing boiler.
Retrofit technologies may not have the impact or visibility of renewable technologies, but it is important not to underestimate the returns they offer for energy efficiency investments. Retrofit can help schools reduce not only their
energy bills but their carbon footprint, thereby assisting them in meeting their environmental targets. Replacing a 10-15 year old atmospheric boiler with a modern condensing or super condensing boiler, for example, has more than halved energy consumption and bills for some schools. Whilst requiring relatively low initial outlay, they deliver rapid financial payback. Clean burning and low in harmful NOx emissions, they are proven to reduce carbon emissions by up to 90 per cent.
Advances in condensing boiler technology apply not only to their improved efficiencies but also to innovations in their design. One such example is the introduction of condensing boiler models that can be disassembled into sections for ease of installation. This feature is particularly advantageous in old school buildings where access to the plant room is difficult due to its location, typically in the basement, or accessible only through narrow stairways and corridors.
Boilers that can be disassembled to facilitate entry into the plant room speed up installation time and therefore reduce labour costs. Any disruption is also minimal as the disassembled boiler can be reassembled and installed with no need for hire of additional equipment such as cranes to lower the boiler in through the window.
Modern heating solutions such as prefabricated heating systems also make boiler replacements easier and more flexible to carry out. With disruption kept to a bare minimum, schools are no longer constrained to restrict such energy saving improvements to the holiday period. Condensing boilers on a cascade system, for example, are delivered on site in a pre-assembled wheeled unit. Not only does this reduce the installation time, which in turn reduces labour costs, but quality control is also improved as the pre-configured unit is pre-tested and delivered as a whole system, from a single supplier, rather than individual components.
Furthermore, installing boilers in a modular design on a cascade system allows the heat output demand to be matched more accurately and more reliably in a fraction of the space.
According to a report by the Committee on Carcinology for the Department of Education, about three-quarters of England's 24,000 schools are estimated to have some buildings with asbestos. The Government's recommendation is to leave the asbestos in place undisturbed. Fortunately for schools wishing to replace ageing boilers, the speed and ease with which prefabricated heating system such as modern condensing boilers on a cascade system can be fitted can help them in the management of their existing asbestos problems and ensure no disruption during the school day.
In order to achieve maximum 'Blue Efficiency' levels from heating, however, it is important to consider the system design as a whole. For this reason, the boiler should be seen as the first part in the refurbishment project. Adding the appropriate advanced control will ensure that the boiler operates at its optimum efficiency level for maximum energy and carbon savings. Controls are simple to fit and use and, what's more, typically achieve payback in just one to two years.
Adding low temperature radiators is another consideration. This will allow the boilers to operate at reduced temperatures which will help them to achieve higher efficiency and energy savings.
Low temperature radiators are particularly suitable for schools as they remove any scald hazard from exposed pipework for the protection of the children.
However, on old heating systems which by their nature take more energy to heat, even the most efficient boilers could struggle to achieve their maximum quoted efficiencies as they are sized on high flow and return temperatures, which prevents the boiler from fully condensing. In such cases, it is worth looking beyond condensing to 'super condensing' passive flue gas heat recovery technology. Such systems use energy input still more effectively and profitably, delivering an outstanding 107 NCV per cent efficiency at all times irrespective of flow and return temperatures. These heat recovery devices are the optimal solution for retrofit and refurbishment projects as they deliver maximum condensing efficiency and maximum use of the energy input, recovering any otherwise wasted energy for the benefit of space heating or cold water preheat.
For schools keen to stretch the strained budgets further and help fight climate change, the good news is that the technology is here now to deliver affordable energy efficient heating with rapid financial payback.
At Remeha Commercial we look forward to helping schools become energy smart with 'Blue Efficiency' level, energy-efficient heating.
// The author is the national sales manager at Remeha Commercial //
1 April 2014