YOUR INDUSTRIAL WASTE HEAT RECOVERY SOLUTION

Norrel delivers a complete,  fit for purpose waste heat recovery system, the ThermStar System™. ThermStar is engineered for tough industrial and commercial ventilation environments. At the heart of the system is Lepido™, a rugged heat exchanger built specifically to operate in polluted exhaust air, where traditional systems clog or fail.

Our system reclaims thermal energy from air streams contaminated with grease, soot, lint, or moisture, and transfers that heat into usable energy, typically to preheat incoming air or water, without disrupting your existing processes.

From industrial laundries and food production to drying and curing lines or commercial kitchens, our solution helps facilities reduce energy costs and CO2 emissions by recovering value from what was previously lost to the atmosphere.

Integrated Into the ThermStar System™

Norrel’s ThermStar System™ combines the power of the Lepido™ unit with a fully integrated solution:

This turnkey solution is designed for fast deployment and long-term reliability by preferred mechanical contractors using our installation guidelines.

Before

After

Ideal Applications

Industrial & Commercial Laundries

Recovers heat from humid, lint and detergent laden exhaust streams in tunnel washers, tumble dryers, and finishing equipment.

See how CWS Workwear uses Lepido to cut energy costs.

Food Processing, Baking & Commercial Kitchens

Handles grease, steam, and particulates in food production and restaurant exhaust from industrial snack lines to quick-service kitchens.

Drying, Curing & Manufacturing Processes

Ideal for thermal exhaust in textiles, polymers, foundries, and beyond including challenging contaminants like fibers, resins, and dust.

Explore Sports & Leisure Group and Bruzaholms Foundry.

Lepido™ Heat Recovery Unit

Reclaim Waste Heat.  Energy Savings Delivered

Lepido™ is a patented Swedish innovation developed by Enjay Systems AB, the only heat recovery unit engineered specifically to recover energy from polluted exhaust air. Now available in North America exclusively through Norrel Inc., Lepido forms the heart of our ThermStar System™, turning wasted heat into clean, usable energy for commercial and industrial operations.

Why Lepido™?

In environments like industrial laundries, food processing plants, drying operations, and commercial kitchens, exhaust air is hot, humid, and filled with grease, soot, lint, or chemicals. These conditions quickly clog and render inoperable conventional heat exchangers, but not Lepido™.

Built for Harsh, Polluted Environments

Purpose-designed for industrial airstreams contaminated with grease, moisture, lint, or chemical particulates, Lepido™ features rugged, corrosion-resistant materials and a durable form factor engineered to perform in the toughest conditions, 24/7 and all year long

Engineered to Resist Fouling

Traditional exchangers clog quickly, but Lepido’s patented Particle Repellent Geometry (PRG®) slows down particulate buildup, preserving high thermal efficiency and reducing maintenance frequency, even in dirty, grease laden exhaust.

High Thermal Efficiency

Recovers up to 60% of thermal energy, sometimes more, redirecting it to preheat process air, hot water, or HVAC systems. The result: lower energy bills, lower emissions, and faster ROI

Without Lepido™

With Lepido™

Lepido™ is currently being used by commercial kitchens, production facilities around Europe to recapture excess heat in polluted exhaust air. At Europes biggest pancake factory located in the south of Sweden, the system will recover 1,500,000 kWh per year.

How Lepido™ Works

Particle Repellent Geometry (PRG), reclaiming waste heat in environments where others can’t.

Unlike traditional heat exchangers that rely on tightly spaced fins, Lepido features a finless, open coil design that works with the natural flow of contaminated air.

Grease, soot, moisture, and other particles pass through the exchanger without clogging or sticking to the surface. This drastically reduces buildup, pressure drop, and the need for frequent maintenance.

Its larger structure allows for ample spacing between coils, creating a unique airflow pattern where particles are repelled rather than trapped. Despite its open design, Lepido maintains the same heat transfer surface area as conventional systems by using 100% counter-current flow and multiple fluid patterns.

The Results?

Long lasting performance, substantial energy recovery, even in the harshest industrial environments.

Reclaim Waste Heat. Energy Savings Delivered

Typical savings are 50-65% of the energy is reused saving significant amounts of CO2 on every installation.

In 2025, Enjay is celebrating their 10 year anniversary since launching their products. No Lepido has ever been returned to the company.

Lepido™ waste heat recovery system