It’s impossible to mention CHP without stressing the importance of accurate sizing to ensure maximum performance and benefits. Get the sizing right and a continuously-running CHP unit will generate low cost, low carbon electricity as a by-product of producing base load heating.
The hydraulic design is equally important as CHP operates more effectively and efficiently at lower system return temperatures. Connecting the CHP return to the lowest available temperature will guarantee the longest possible running hours from the CHP system and the greatest economic benefits.
These design factors need to be considered at the outset. And given that 80% of the lifetime costs of a building occur in the operational phase, it follows that future maintenance should also be addressed at the early stages.
All heating equipment benefits from routine maintenance to keep it operating efficiently and reliably – and CHP is no exception. Good suppliers will offer a choice of CHP service levels, all of which include inspections at regular intervals, typically at around 6,000 CHP operating hours for a 20kWe unit.
What does the service include? Just like a car service, scheduled CHP services will include checking, and replacing where necessary, service parts. Engine oil will be analysed as will water quality. This will help prevent the inconvenience and costs associated with breakdown.
When investing in CHP, it’s worth considering units that have system separation which is normally achieved by an integrated plate heat exchanger. This will protect it from any debris or contamination in older heating systems and increase its service life.
Almost all buildings emit air pollution due to combustion in their heating, cooling or electricity generation systems.
Mind the NOx
More stringent NOx emissions requirements have been introduced for CHP, amongst other heating equipment, in response to the drive for improved air quality. The environmental assessment scheme BREEAM, for example, has introduced a new NOx benchmark of 50 mg/kWh (0% O2) or less for new build developments. Still-tighter NOx emission levels of 40 mg/kWh (0% O2) or lower are required from heating in high pollution areas in the Capital under the London Plan.
Ultra-low NOx CHP systems like the R-Gen series are fully compliant with all environmental and NOx legislation. But to ensure that the appropriate NOx levels are met throughout the lifecycle of the CHP unit, opt for service plans that include emission monitoring as an integral component of the programme.
Using experienced, dedicated CHP engineers to service the unit means that maintenance is carried out with minimum disruption.
And as an estimated 85% of reported CHP faults are able to be corrected and reset remotely, this reduces downtime, inconvenience and costs still further – as well as the carbon emissions associated with a site visit.