High-efficiency or condensing boilers

High-efficiency or condensing boilers
© exclusive-design, image #164977506, 2017, source:
All sectors
Investment cost:
High cost
Payback time:
5.9 Year(s)
Cost savings:
27688€ / Annual: € 27 688 (£ 25 402)
Resource type:
Resource saving:
Annual: higher plant efficiency; better boiler modulation; 846 720 kWh or 5-20 % decrease in kg CO2 equivalent
Investment cost:
109€ / € 109 per kW (£ 100); costs may drop with increasing project scale; for example, assuming planning permits can be avoided, asbestos surveys for plant items and coring, flue condition assessment, piping condition assessment (pipework might be old and pressurisation poor); typical boiler maintenance required as per schedule; fewer breakdowns expected
Assumptions taken in the presentation of the above performance indicators:

Replace ageing boiler plant with gas-condensing or high-efficiency equivalent; recommended where existing plant is greater than 15 years old or it is oversized for application; gas heating plant with 1.5 MW LTHW boilers replaced with three no-floor-standing gas boilers of 1 MW total output; new pumps for primary circuit and low-loss header; new spill press kit; new common flue to standards, terminated at 10 m; efficiency improved by 20 %; 5 200 hours per annum operation

High-efficiency or condensing boilers reduce utility bills and increase energy efficiency compared to ageing boiler units. They are also smaller and lighter than traditional boilers.

Condensing boilers can be controlled via a thermostat and achieve savings between 10 % and 30 %.

Where a single 200 kW boiler, heating an office with a single-shift system, uses around 300 000 kWh of gas a year, a 10 % saving rate corresponds to € 845 (£ 750) a year with gas prices at € 0.03 per kWh (2.5 pence). The extra cost of a condensing boiler would be around € 1 690 (£ 1 500), giving a payback in around two years.

Want to know if relevant support is offered in your country?