Boilers – the sustainable heating choice
Renewable technologies may grab all the headlines, but today’s high efficiency boiler and heat recovery systems can massively cut fuel bills and emissions without huge capital expenditure. James Porter, National Sales Manager of Remeha Commercial, explains how local authorities can save money on their heating.
Local authorities are having a tough time of things. As economic growth has stagnated, the government is struggling to balance the books and has imposed even tougher cuts on an already embattled public sector. With less money in the coffers, saving money on your heating bills should be a priority for all local authority estate managers.
So how can this be achieved? The majority of savings on any building estate have to come from both a better approach to maintenance of existing building services and simple energy efficiency improvements on refurbishment projects. According to the Carbon Trust, about a third of the UK’s energy consumption is used for heating or producing hot water. A significant proportion of this is provided by commercial boiler plant, so it should be top of the list of any energy reduction strategy. Typically, energy improvements of 10% or more can be made relatively easily through maintenance and low cost improvements.
Putting the right controls on a boiler system is essential. The minimum control strategy should encompass valved zone control, thermostats and timers. Further improvements, such as sequential control of boilers; weather compensation; optimised start/stop and zoned time control can all achieve good savings.
Boiler insulation degrades and on old equipment can account for heat losses of 10% of the energy input. Insulation should be replaced when it is showing signs of wear. Similarly, the insulation on the associated pipework and valves should be replaced over time. This can result in further savings of up to 10% of the energy input.
The flue can cause a flow of air through the boiler even when it is not firing. This cools the boiler and energy is wasted. A flue damper can be used to close off the flue when the boiler is not firing, preventing this energy loss.
Variable speed drives and pumps
On forced/induced-draught boilers, a variable speed drive will allow the fan to operate at lower speeds when less air flow is required. A reduction in fan speed of just 10% can result in fan energy consumption savings of 20%, and a reduction in fan speed of 20% will save up to 40%.
Variable speed pumps can also be fitted to decrease the flow in the system to match demand. This can save 25-50% of the pumping energy consumption.
Effective maintenance is critical to ensure the best performance from your boilers. A full boiler service should be carried out on an annual basis, ideally before the start of the heating season. This service should include flue gas analysis, controls calibration, burner cleaning and limescale treatment.
For example, soot can build up on the fire side of the boiler’s heat exchanger. This creates an insulating layer, inhibiting heat transfer to the water. A 1mm layer of soot will cause a 10% increase in energy input to the boiler to meet the same heat demand.
In hardwater areas, limescale can build up on the water side of the boiler’s heat exchanger. This also creates an insulating layer, again inhibiting heat transfer to the water. A 1mm layer of limescale will cause a 7% increase in energy input to the boiler to meet the same heat demand. The most effective method of limescale removal is through chemical treatment. This should be done annually by a qualified technician.
Quinta Eco Plus
Refurbishment projects open the door to even greater savings. While today’s boilers are very highly energy efficient, we at Remeha Commercial have identified the need to improve efficiencies still further to deliver affordable heating systems that perform well at all operating conditions. The maximum efficiencies achieved by condensing boilers under laboratory conditions at low temperatures (30-50°C)and half load are rarely achieved in real conditions. More typically, boilers are run at high loads and high temperatures and still waste around 20% of the energy input up the flue.
We believe that our latest product, the “super condensing” Quinta Eco Plus, will prove to be the Holy Grail of condensing technology, a system that achieves maximum condensing at all times and at all system temperatures by use of a passive flue gas heat recovery device. Quinta Eco Plus offers a new level of attainable efficiency of 97% GVC at 82/71°C flow and return temperatures. That means £97 of actual usable energy for every £100 of gas input in real time installations rather than laboratory conditions.
We at Remeha Commercial look forward to working with contractors and consultants to bring affordable, replicable, energy efficient heating systems to local authority buildings, helping them lower their carbon emissions and make savings to help ease the strain on the finances.
Why wait for the boiler to break when you can reap financial and environmental benefits now?
When Geoff Berry of Touchstone Energy Services was commissioned to carry out an energy survey at Hatch Mill Nursing Home in Farnham, Surrey, he recommended immediately replacing the existing atmospheric boilers with three Remeha Quinta Eco Plus 65 systems.
The Quinta Eco Plus is a super condensing heating system that recovers waste energy equivalent to 15% of the gross input. At Hatch Mill, this recovered energy pre-heats the incoming boosted cold water feeding the DHW system. This means lower fuel bills for the nursing home as well as reduced carbon emissions.
As the Quinta Eco Plus is prefabricated and configured in a wheel-in enclosure, it made installation quick and simple for Phil Kearn of Hydro Heating Solutions Ltd. The owners of Hatch Mill Nursing Home are now planning to replace their existing boilers with Quinta Eco Plus systems in the second of their two sites.
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