Sol Navitas is an Estonian cleantech company on a mission to make buildings healthier, smarter, and more sustainable — by harnessing solar energy to drive ventilation, moisture control, and indoor climate solutions. At the heart of its approach is a simple belief: a building should support well-being, not compromise it.
Founded by Margus Kullerkupp, the company was born from personal experience with poor indoor air quality and an urgent need for better solutions. “We often treat buildings like sealed boxes,” says Kullerkupp. “But air quality and moisture control are essential — not just for comfort, but for health and the longevity of the building itself.”
Since 2015, Sol Navitas has been developing solar-powered ventilation systems that work with — not against — a building’s orientation, sun exposure, and seasonal conditions. Their solutions use solar air heating and smart controls to ventilate buildings even when no one is home. This makes them especially effective for seasonal homes, off-grid properties, and moisture-prone buildings.
ADAPTING SOLAR VENTILATION ACROSS CLIMATES
What began as a solution for cottages in Estonia has evolved into a full range of solar ventilation systems for homes, offices, and industrial buildings. The technology has proven especially effective in cold, humid climates, where moisture buildup and stale air can lead to mold and structural damage. In the Nordic region, Sol Navitas has become known for its low-energy systems that preserve indoor air quality and extend building lifespan.
Now, the company is expanding into Southern Europe, where the challenges are different — but growing. As homes are increasingly renovated for energy efficiency, they become more airtight and less breathable, trapping moisture and leading to mold, poor air quality, and structural wear. Millions of households in Spain, Italy, and beyond are beginning to feel the impact — not only in holiday properties, but in everyday homes.
We’re not just drying walls or ventilating rooms,” says Kullerkupp. “We’re helping buildings last longer, cost less to run, and feel better to live in. That’s the kind of impact we want to scale.
Rising energy costs and EU climate targets have created momentum for passive, solar-based building solutions that improve ventilation without increasing utility bills. Sol Navitas’ approach — combining solar air heating with smart airflow control — provides a scalable solution that adapts to building orientation, usage, and regional climate.
In 2025, the company’s system also proved critical for flood-damaged homes. Sol Navitas won Hack the Future, a climate resilience hackathon in Valencia, with a post-flood drying and ventilation concept. Pilots are now underway, helping municipalities restore safe living conditions in homes impacted by extreme weather.
HEALTHY BUILDINGS FOR A HEALTHIER PLANET
At its core, Sol Navitas is not just selling ventilation products — it’s reshaping how people think about the relationship between buildings, health, and energy. Its two flagship offerings — Sol Fresh Premium (for small homes and cottages) and the Solar Smart AHU (for full-building integration) — are designed to optimize indoor climate while reducing dependence on fossil fuels.
Too often, ventilation is treated as an afterthought,” says Kullerkupp. “We want to make it intuitive, data-driven, and part of every sustainable building plan.”
The Solar Smart AHU is built around a dual-intake logic: in warm seasons, it uses cooler northern air for passive cooling; in colder periods, it draws heated air from solar collectors to pre-warm incoming ventilation air. Humidity sensors and smart bypass controls ensure optimal performance across seasons. This reduces energy bills, improves comfort, and helps prevent moisture-related problems before they start.
Sol Navitas also supports building renovation and retrofitting, offering components that can be installed into existing ventilation units — giving old systems new life with solar integration, sensors, and smart controls.
A DATA-DRIVEN FUTURE FOR THE BUILDING INDUSTRY
As the company scales, it is developing a software platform to help architects and engineers integrate solar thermal ventilation into building design from the start. The tool will combine real-world climate data, material performance, and facade orientation to guide smarter decisions. Over time, this platform will form the backbone of a BIM-integrated SaaS solution, enabling climate-responsive design at scale.
A VISION ROOTED IN VALUES
Sol Navitas is driven by values of sustainability, well-being, and simplicity. The company combines technical innovation with a human-centered mission: to help buildings breathe, to reduce dependence on mechanical systems, and to create spaces where people can thrive — all while using the energy we already have: the sun.
In a changing climate, proper ventilation isn’t just about comfort — it’s about health, safety, and resilience,” — Kullerkupp
