The internal wall element comprises three panels, each 42 mm thick, with internal circulating channels. On both sides of the middle element, heating foils are affixed, ranging from 150 to 200 W/m2. This configuration allows the three elements to be heated up to 48°C. Each 600 mm wide element has the capacity to store up to 1.2 kWh of heat energy.
During peak hours of high electric prices, the heat is released from the elements by circulating warm air through all panels within the element. The heat flux into the room space on both sides of the element is adjustable, with a maximum capacity of 500 W, though it typically operates at 250 W. Each element is outfitted with a microcontroller, equipped with temperature and relative humidity sensors, along with circulating fans. The microprocessor is connected to a WiFi network and can be controlled either by the homeowner or the local electric energy distribution company
External wall elements typically consist of six 42 mm panels, similar to those used in internal wall elements. These elements are heated using a heat pump system, akin to the widely adopted air-to-air systems in Nordic countries. Warm air, approximately 42°C, is drawn from the heat pump system into the channels within the element, effectively raising the wall elements' temperature to around 40°C. The extraction process is carried out similarly to the internal wall elements, but in one direction only. On the opposite side, a load-bearing wall structure with insulation is installed. This heating approach boasts double the efficiency, thanks to the incorporation of a heat pump. When combined with off-peak electricity pricing, it offers the most cost-effective method for heating single-family houses in Nordic countries.
FS-B thermal storage units
FS-B thermal storage units are designed to be as convenient as furniture. Arriving in flat packs, they are easily assembled and ready to be plugged into the grid, poised to harness low-cost electricity during off-peak hours. The flexibility of these units lies in their ability to utilize a variety of local raw materials for the core thermal storage elements. Wood is just one example; other materials, such as empty beverage cartons, can also be employed to create these versatile heat storage units.
Thermal Accumulator Elements
Wood is an exceptional material for thermal storage. It boasts nearly as impressive heat energy storage capacity per unit volume as bricks, but weighs less than one third.
The reason wood hasn't been commonly used as thermal mass is due to its insulating properties. Until now, transferring heat into a wooden structure and redistributing it back into the living space has posed a challenge. Finnshield has ingeniously addressed this hurdle by employing electrically heated foils, akin to those used in ceiling heating, within internal walls to warm the structure. Air channels equipped with circulating fans then efficiently distribute the heat to the surface of the living area. In the external wall system, a heat pump is utilized to heat the circulating air for the same purpose. All heat storage elements are crafted from wooden particles, akin to particleboard core fractions. The binder may consist of either lignin-based glue or even recycled plastic. The manufacturing process is akin to standard particleboard production, or in the case of elements incorporating recycled plastic, it follows the methodology employed for other building blocks.
Electric heating stands out as the most dependable heating option with the added advantage of being cost-effective. When combined with thermal mass storage to offset peak hour expenses, it becomes most likely the most economical choice in the Nordic Countries.
Second great advantage is that FinnShield offers significant contributions to reducing CO2 emissions through two primary methods. Firstly, the material used in FinnShield is derived from sawdust or recycled wood, which would otherwise be burned and emit approximately 1.8 kg of CO2 per kilogram of wood. By utilizing this waste material, FinnShield prevents the release of CO2 and effectively reduces emissions.
Secondly, FinnShield aids in reducing peaks of electricity consumption . By optimizing energy usage, it minimizes the reliance on the grid and minimizes electricity generated from burning bio-fuels, which emits approximately 900 g of CO2 per kilowatt-hour (g/kWh). Instead, FinnShield promotes the shift towards more sustainable energy sources, with emissions as low as 30 to 40 g/kWh.
In summary, FinnShield plays a crucial role in mitigating CO2 emissions by utilizing recycled wood, preventing unnecessary burning, and facilitating the transition to sustainable energy sources, ultimately contributing to a greener and more environmentally friendly future.