The house tour starts outside, at the location where the electrical panel would normally sit. The wires are clearly unplugged, signaling an intentional detachment from the grid. Inside, a family lives without worrying about the electricity bill, as the home harvests every ray of sunlight and turns it into usable energy through a technology now represented by Sunthalpy Engineering. The guide for this walk through the Villamejil chalet on the edge of Naranco is Baudilio Alonso, the company’s commercial director. The tour continues from the first floor after entering. There are bedrooms, and the family pictured on the day is not present; the company crew is at home. Alonso remarks with a spark of fascination about the bathroom equipment, noting a dressing room and a climate that feels surprising for a space that seems ordinary. The absence of humidity, the breathable air, and the lack of radiators are all part of the experience. The key, he explains, is underfloor heating that avoids condensation and keeps humidity even, regardless of conditions.
Down on the ground floor, a kitchen, a generous living room, and several rooms filled with machinery set the stage for what many would call a living laboratory. The view from a window includes the Cathedral tower, Aramo, and the old municipal prison. Alonso calls the chalet a remarkable testing ground and points to two doors behind which the equipment keeps the house running without traditional outlets. He emphasizes that these rooms are crucial. He elaborates: with the market’s most efficient underfloor heating, the circulating water is at about 21 degrees, a temperature you can touch. He demonstrates by placing a hand on the warm-but-not-hot ground, noting that barefoot comfort is always possible. The method uses a double-layer solar array surrounding the home, with a thermal section behind it. The external layer generates electricity while the inner layer captures heat that travels through a closed hydraulic loop to a heat pump. This process keeps the system at a gentle, constant temperature of 21 degrees. Alonso stresses that the goal is comfort without overheating, and that the body should not feel chilled or overheated as a radiator might. He adds that the heat pump activates in tandem with the doors, ensuring the machines stay quietly powered in the background.
After confirming the mechanism’s integrity and the absence of leaks, the team shifts the concept into a mobile unit that can be placed outside existing homes to deliver all heating and hot water. The aim is to reduce fuel consumption from petrol or diesel and lower energy costs, a timely relief as bills rise. Alonso notes that industrialization is a key objective.
With energy bills climbing, demand shows a strong uptrend. The team has roughly 25 active projects and has prioritized industrializing the entire process using internal resources. The marketed unit resembles a canopy designed for single-family homes. Plans are underway to adapt the concept for apartments as well. The approach involves removing traditional radiators and introducing radiant walls on the floor or wall surfaces using the same technology, with exterior walls serving as additional insulation. The overarching idea is to dramatically reduce gas usage. Alonso points out that some homes already spend 300 to 400 euros on gas, and a notable share of buildings could benefit from gas dissipation reduction. For apartment sales now, buyers are often asked to consider energy consumption, a question that Sunthalpy holds at the core. The company’s patented system, created by founder Omar Suárez, benefits from a team that includes many veterans from the refractory industry, all contributing to the project’s breadth and depth.
The visit concludes outside beside a fully enclosed pool kept at a steady 27 degrees. A curious question from the sister-in-law prompts a final note: what happens on days with limited daylight in winter? Alonso responds that there were two days in November last year when photovoltaic production stopped entirely in Asturias. On those days, battery reserves were depleted, and the household constraint was simple: the children should avoid playing on the PlayStation because energy use there was the dominant factor in consumption. The takeaway is clear: the system is designed for consistent comfort, even when the sun isn’t shining, with a strong emphasis on efficiency and practicality. This account reflects the efforts described by Sunthalpy Engineering and its team, who continue to pursue scalable, field-ready solutions for homes across regions similar to Asturias.