Context

This Private residence in Weinfelden (Switzerland) required a new heating system and additional power when the former oil-heated system needed replacement. With the swimming pool in use year-around and hot-water boiler, this building has a pretty stable heat-demand throughout the seasons.

Additonal power supply was required for the cars. The pool has a costly heatdemand at altitude in the Swiss climate. With rising prices and increasing demand for electricity, CHP was considered.

The Use Case

• Location: Private residence in Weinfelden, Switzerland installed late 2019.
• The EnerTwin was selected to cover the base load of both heat and power demand and complimented with solarpanels.
• The challenge was initiated by replacement of a traditional condensing boiler due to age. Silent operation, as the unit would be operating in the proximity of the living area, was mandatory. Engine-based CHP systems were therefore found unsuitable. The building would also not allow for costly changes for low-temperature systems that are required by other systems such as heatpumps.
• Annual estimated running hours: 5500+ hrs

The role of the EnerTwin

The EnerTwin is separated from the main heating circuit by a plate heat exchanger, while the heat is used to heat the pool. Control is based on the temperature of the poolwater. Electricity is used in the poolpumps and garage.

Factual results of the project

• Installation: Installation costs totaled at CHF 3500
• Annual running hours: 5500-6000 hrs
• An additional boiler was installed for peak-demand
• Reliable heating solution covering >80% of heatload
• Subventions have been granted
• Reduction of energybill achieved
• Climate goals have been achieved with CO₂ and NOₓ emissions reduced by 8,5 Tons a year
• Silent operation, inaudable in the living area’s
• Plug&Play installation reduced impact to the residents

“Soft” results of the project, the client feedback

• Sustainability aspects for the family were considered important. The EnerTwin provides a reliable and comfortable system for the swimming pool.
• The results that surfaced after the first year of operation regarding CO2 reduction based on the runhours were impressive. Without buffervessel the unit still overachieves in runhours at 6000 hours per year.
• The complimentary character of the system with the solarpanels combined, generates a stable energy profile making the house a close to full autarkic profile.