Flexit — 50 years of Norwegian ventilation engineering
Flexit is one of Scandinavia's leading manufacturers of ventilation and heat recovery systems. Founded in 1974 in Norway, Flexit brings fresh air and energy efficiency to homes and commercial buildings across Europe.
From a small workshop to Scandinavia's market leader
Flexit has been developing ventilation solutions for over 50 years. What began as a family business in a rented workshop is now Norway's largest manufacturer of residential ventilation systems.
Flexit AS was founded in 1974 by Finn Martinsen and his wife Anne-Marie in Ørje, a small town in southeastern Norway. The company started with a simple goal: to improve the way homes are ventilated.
Flexit was one of the first companies in Europe to focus on balanced ventilation with heat recovery. While others were still relying on natural ventilation or simple exhaust fans, Flexit was already engineering systems that recover heat from outgoing air — a technology that has since become the standard for modern buildings.
Over the decades, Flexit has released numerous generations of heat recovery units, each building on the lessons of the previous one. This iterative engineering approach means Flexit doesn’t need to learn what works — they already know what to avoid and what delivers results. That depth of experience is something no newcomer to the market can replicate.
With a turnover exceeding 800 million NOK and approximately 270 employees across Norway and Sweden, Flexit remains a family-owned business, now led by the third generation of the Martinsen family.
In-house laboratories that set industry standards
Flexit doesn’t outsource testing. Every unit is validated in their own facilities before it reaches the market — from acoustic performance to climate simulation under extreme Nordic conditions.
Acoustic laboratory
One of the most advanced acoustic testing labs in Northern Europe. Measures and optimizes noise levels down to the decibel, in cooperation with Norwegian universities.
Climate & performance testing
Dedicated test chambers simulate Nordic winters, extreme humidity and temperature differentials to verify heat recovery, airflow and energy consumption.
University partnerships
Collaboration with NTNU and SINTEF ensures R&D is grounded in the latest scientific findings on indoor climate and building physics — with academic oversight of testing.
Finn Martinsen founds Flexit in Ørje, Norway. Production of air vents and flexible aluminium ducts begins.
Flexit develops its first ventilation units with integrated heat recovery, responding to the rising demand for energy-efficient buildings.
Expansion into Sweden, Finland and Central Europe. A new factory opens in Töcksfors, Sweden. Flexit becomes Norway's market leader.
260+ employees, 800M+ NOK turnover. Launch of EcoNordic — a system combining ventilation with heat pump technology. Smart control via Flexit GO app.
Documented quality throughout the entire value chain
Flexit develops and manufactures its products in Norway and Sweden, maintaining control of the entire value chain — from idea and development to finished product.
What makes Flexit units stand out
Flexit ventilation systems are designed for the harsh Scandinavian climate — built tough, energy-efficient, and whisper-quiet.
Flexit rotary and counter-flow heat exchangers recover up to 95% of heat from exhaust air, significantly reducing heating costs.
Noise levels as low as 22 dB on the lowest setting. Flexit units are designed for continuous operation without disturbing sleep or work.
Control your ventilation from anywhere using the Flexit GO app. Adjust airflow, set schedules, monitor filter status and energy consumption.
A comprehensive product range from single-room ventilators (Roomie) to large commercial air handling units (ProNordic) with airflows up to 5,000 m³/h.
Designed and manufactured in Scandinavia with premium materials. Every Flexit unit undergoes rigorous testing before it leaves the factory.
Flexit rotary heat exchangers naturally recover moisture, eliminating the need for electric pre-heaters in most climates and reducing energy use even further.
Innovation for health, comfort and energy efficiency
The construction industry has changed significantly — from naturally ventilated, draughty buildings to today’s highly airtight and energy-efficient structures. Modern buildings require ventilation systems that handle Nordic climate conditions, minimise heat loss and ensure a healthy indoor climate.
Stricter EU requirements, new regulations and evolving standards make this work increasingly important. Flexit develops solutions that support the transition towards passive houses, nearly zero-energy buildings and plus-energy buildings — structures that produce as much energy as they consume.
With advanced laboratory facilities, modern testing equipment and extensive R&D cooperation with SINTEF, Flexit strengthens its position as a leading partner for future-oriented ventilation solutions. The goal: cost-efficient buildings during construction and energy-efficient buildings during operation — without compromising indoor climate quality.
Ventilation systems designed for maximum heat recovery and minimal energy consumption — supporting passive house and zero-energy building standards.
Advanced filtration and balanced ventilation ensure clean, fresh air in every room — reducing allergens, CO₂ and moisture for better health and comfort.
Built to withstand Nordic extremes for 30+ years. Flexit units continue to perform without major component replacements throughout the building’s lifetime.
Stage Wheel — a revolution in rotary heat exchangers
Nothing like it exists on the market
In 2025, Flexit unveiled Stage Wheel — a patented rotary heat exchanger technology that transfers heat through the rotor wheel in multiple stages. A specially designed recuperator with optimized geometric shape and material thickness allows the heat exchanger to capture a significantly greater proportion of energy from the exhaust air.
Real-world measurements confirm that Stage Wheel delivers up to 10% more energy recovery compared to the best conventional rotary heat exchangers. No other manufacturer has achieved this level of performance in a rotary exchanger — it is unique in the global HVAC market.
Flexit units are designed to last the entire lifetime of a building — without requiring major component replacements. While competitors’ enthalpy exchangers need replacing after 5 years, a Flexit unit keeps performing decade after decade.
Built to last. Built to sustain.
Flexit has made a conscious strategic decision to focus on durability and sustainability. Their philosophy is simple: the most sustainable unit is the one you never need to replace. Every Flexit product is engineered to deliver a minimum 30-year service life without major component replacements.
Unlike manufacturers who use EPP and EPS foam materials — which are prone to mold, condensation, and require enthalpy exchanger replacement every 5 years — Flexit deliberately avoids these materials. The result is a unit that stays hygienic, efficient and reliable for the entire lifetime of the building.
Flexit holds ISO 14001 environmental certification and provides Environmental Product Declarations (EPDs) for its product lines, offering verified data on environmental impact throughout the product lifecycle. These declarations help architects and builders earn points in green building standards like BREEAM, LEED and FutureBuilt.
Solutions for every building type
From compact single-room ventilators to powerful commercial air handling units — Flexit covers the full spectrum of ventilation needs.
Central heat recovery units for single-family homes. The Nordic series delivers balanced ventilation with up to 90% heat recovery efficiency, quiet operation and smart control via Flexit GO app.
Professional air handling units for office buildings, schools, shopping centres and other commercial spaces. Modular design with high heat recovery efficiency and robust construction.
Compact balanced ventilators for individual rooms. Recover up to 95% of heat without any ductwork. Ideal for renovations and apartments where a central system is not feasible.
VENTIT — your exclusive Flexit partner in Slovakia & Czech Republic
VENTIT is the exclusive authorized distributor of Flexit for Slovakia and the Czech Republic. Our partnership ensures that you receive genuine Flexit products with full manufacturer warranty, competitive pricing and expert technical support.
With over 15 years of experience in HVAC, our team of engineers helps you select the right Flexit unit for your project, provides duct layout design assistance, and offers ongoing technical support throughout the installation process.
Looking for a Flexit ventilation system?
Whether you are an installer, designer or building owner — our team will help you choose the right Flexit unit, prepare a tailored quote and provide full technical support.