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News blog8 May 20231 min read

Innovative heating replacement in Guisasola residential, Ovideo, Asturias

Innovative heating replacement in Guisasola residential, Ovideo, Asturias

An old coal heating system in Oviedo, Asturias, has been replaced with an innovative heating system that also includes DHW, an aerothermal system and photovoltaic panels. The building is made of 72 households, it was built on 1963 and has 7.440 m2 with no surrounding buildings, so the thermal losses on the façade are important. Around 288 people live there, and it has been equipped with an individualized monitoring system that measures consumption with remote viewing and thermostatic valves in each household. Due to the complex access to the boiler room and the desire of achieving maximum efficiency, it was installed as a cascade boiler system of the Okofen brand.

The reasons that lead to installing a new heating system were the old system was outdated and very polluting because of the coal. Also, the building was looking to obtain the highest energy qualification possible. Anyhow, there were a few problems during the installation, like the need of dismantling all boilers to fit them into the boiler room. For now, the building enjoys the guarantee of an optimal operation by the energy service company and significant economical and emissions savings. The replacement of the system benefitted from renewable energies subsidies from the “Consejería de Empleo, Industria y Turismo” of Asturias (2011-2020).

New heating system in use Biomass pellet
Previous replaced heating system Coal
Building type Residential
Useful energy demand (kWh/m2a) – Before and after building shell renovation Before: 108.48 kWh/m2a
After: 87.23 kWh/m2a
Installed capacity (kWth) – Before and after Before: 950 kW
After: (624+16+5.4) kW
Input energy – Before and after Before: 1,008,828 kWh
After: 763,611 kWh
Initial investment (purchase and installation) 311,780 + IVA €
Yearly savings on the energy bill (compared to previous system) 36,714.53 €
Yearly energy savings (compared to previous system) 254,217 kWh
Yearly CO2 emission reductions (only heating system replacement) 453.6 t CO2

This best practice is issued from the activities of Work Package 4 “Preparation of instruments for replacement campaigns” of the REPLACE project. Read it now to discover many more best practices illustrating the benefits of innovative low-carbon and renewable heating and cooling systems.


Publication date
8 May 2023