SEW

What SEW does

SEW GmbH (Systemtechnik für Energierecycling und Wärmeflussbegrenzung GmbH) is a privately held, family-owned German energy technology company founded in 1983 and headquartered in Kempen, North Rhine-Westphalia. The company manufactures GSWT® (Gegenstrom-Schicht-Wärmetauscher), a proprietary counterflow layer heat exchanger platform for heat and cold recovery in ventilation and air conditioning systems. The technology achieves up to 90% heat exchange efficiency with absolute physical separation between exhaust and fresh air streams, providing germ- and pollutant-free climate transfer — a critical capability for hospitals, pharmaceutical production, infection research centers, and heritage cultural buildings. The company is led by Managing Director Jörn Eßmeyer and operates with a workforce of 51-100 employees.

The product portfolio centers on the GSWT® platform with multiple system variants (Basis, Standard, Multifunktional, Multifunktionales Komfort, and Multifunktionale Hallenbadtechnik for swimming pools), supported by heaters/coolers, recooling systems, room air conditioning units, an ASM connection-switching and monitoring unit, pump valve assemblies (PAG), after-coolers, and an indirect adiabatic evaporative cooling add-on. Modular construction enables installation in confined spaces and heritage buildings where conventional systems cannot fit. The SEW® and GSWT® names are registered trademarks.

SEW generates revenue through a project-based enterprise sales model. Sales is mediated by TGA planners (technical building equipment planners) and engineering consultants who specify GSWT systems into building projects at design phase; SEW then delivers custom-engineered equipment, installation supervision, commissioning, and operator training. Pricing is quote-based with no public list, and customer relationships are dominated by long-duration institutional engagements. Named customers include the German Federal Chancellery (Bundeskanzleramt Berlin), Charité Berlin, Klinikum Stuttgart (56 systems since 1993), RWTH Aachen, Medizinische Hochschule Hannover, Fraport AG Frankfurt, Deutsche Bundesbank Frankfurt, GlaxoSmithKline Biologicals Dresden, Helmholtz-Zentrum Braunschweig, and The Charles Hotel München. Operations span Germany, Austria, and Luxembourg.

Name

SEW

Legal name

SEW® Systemtechnik für Energierecycling und Wärmeflussbegrenzung GmbH

Website

https://sew-kempen.de

Company type

Private

Founded year

1984

Operating status

Operating

Headcount range

51–100 employees

Short description

SEW GmbH is a German family-owned manufacturer of the proprietary GSWT® counterflow layer heat exchanger technology for heat and cold recovery in ventilation systems, serving hospitals, government buildings, universities, airports and heritage cultural venues across Germany, Austria and Luxembourg.

Ownership category

akta.pro rank

Product category

HVAC heat recovery systems

NAICS

Heating Equipment (except Warm Air Furnaces) Manufacturing (333414), Power Boiler and Heat Exchanger Manufacturing (33241), Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial Refrigeration Equipment Manufacturing (333415)

SIC

Air-Cond & Warm Air Heatg Equip & Comm & Indl Refrig Equip (3585), Heating Equipment, Except Electric & Warm Air Furnaces (3433), Pumps & Pumping Equipment (3561)

akta.pro primary industry

Heat Exchangers & Thermal Transfer Equipment (IMAHAKAC)

akta.pro secondary industry

Heat Exchangers, Coils & Hydronic HVAC Components (IMADANAF)

Keywords

• Heat recovery systems
• HVAC manufacturing
• Ventilation heat exchangers
• Energy recycling systems
• Evaporative cooling

Headquarters

HQ city

Kempen

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Personnel, Operations, Technology or R&D, Marketing or Sales

Revenue model

1. Heat Recovery System Sales and Installation: Sale and installation of complete GSWT® heat recovery systems for new construction and retrofit projects. Revenue is generated through equipment sales, custom engineering, installation supervision, commissioning, and operator training services. Projects range from single units to multi-system installations across entire building complexes.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels8 records

Core offering

SEW designs, manufactures and supplies GSWT® counterflow layer heat exchanger systems (Kreislaufverbundsysteme) for heat and cold recovery in HVAC and ventilation installations. The modular product line spans entry-level, standard and multi-functional configurations plus variants for swimming pools and comfort applications, and is sold as engineered, custom-configured equipment with installation supervision, commissioning and operator training.

Product overview

SEW GmbH (Systemtechnik für Energierecycling und Wärmeflussbegrenzung) is a manufacturer of circular compound systems (Kreislaufverbundsysteme) for heat recovery and cooling recovery in ventilation and air conditioning applications. The product portfolio centers on the GSWT® technology platform, which provides germ-free and pollutant-free heat transfer with up to 90% efficiency. The GSWT® core technology serves as the foundation, with multiple product variants including Basis, Standard, and Multifunktional (multi-functional) systems that scale in capability. Specialized variants address specific applications such as swimming pool technology (Hallenbadtechnik). Supporting components include heaters/coolers, recooling systems, room air conditioning units, connection switching units with monitoring (ASM), pump valve assemblies (PAG), and after-coolers. An indirect adiabatic evaporative cooling function provides additional cooling capability. The modular architecture enables customized solutions for various building types including hospitals, hotels, universities, commercial buildings, and industrial facilities. Founded in 1984, the company operates exclusively in physical HVAC systems with no software or API offerings.

Differentiator

Problem solved

Functional benefit

Products and services

• GSWT® Technology Platform (Counterflow Layer Heat Exchanger) Core proprietary technology platform for SEW's heat and cold recovery installations, enabling up to 90% heat exchange efficiency with germ-free and pollutant-free separation between exhaust and fresh air streams, modular redundant construction, in-place cleaning and adaptable to any air volume or building dimension. Used as the foundation for all SEW engineered HVAC projects.
• GSWT® Heater / Cooler (Erhitzer / -Kühler) Heat exchanger units that provide both heating and cooling functions within the GSWT® system, enabling efficient temperature control in ventilation applications for hospitals, commercial and industrial buildings.
• GSWT® Basis System Entry-level circular compound system variant offering core GSWT® heat recovery functionality with essential features for standard building applications.
• GSWT® Standard System Mid-range circular compound system with enhanced performance characteristics and broader application scope for commercial and institutional buildings.
• GSWT® Multifunctional System Multi-functional circular compound system providing comprehensive heat recovery, cold recovery and additional operational capabilities for demanding HVAC installations.
• GSWT® Multifunctional Comfort System Enhanced multi-functional system designed for maximum comfort applications, offering premium climate control capabilities for hotels, museums and high-spec institutional buildings.
• GSWT® Multifunctional Swimming Pool Technology (Hallenbadtechnik) Specialized multi-functional GSWT variant specifically designed for indoor swimming pool applications, handling high humidity, aggressive pool air and temperature differential requirements with dehumidification and heat recovery.
• GSWT® Recooling Systems (Rückkühlwerke) Recooling system units that work in conjunction with the GSWT® heat recovery system to manage cooling tower loads and enhance overall HVAC efficiency.
• GSWT® Room Air Conditioning Units (Raumluftkonditioniergeräte) Decentralized room air conditioning units integrated with the GSWT® system for localized climate control in individual rooms or zones.
• Indirect Adiabatic Evaporative Cooling Supplementary cooling function using indirect adiabatic evaporative cooling combined with the operating-safe circular connection system, reducing supply air temperature through water evaporation without adding humidity to the supply air stream.

Quantifiable outcome

• 30-80% reduction in energy costs for heating and cooling compared to conventional HVAC systems
• +7 more outcomes

Named customers14 records

Segments6 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Scale indicators3 records

Recent moves4 records

Expansion highlights5 records

Broad incumbents

• Systemair AB: Systemair is a European HVAC manufacturer with a broad portfolio of air-handling units and energy-recovery ventilation systems, making it a relevant incumbent peer for SEW's ventilation heat recovery solutions.
• Swegon AB: Swegon is a Nordic indoor climate solutions provider offering energy-recovery ventilators and air-handling units for commercial buildings, comparable to SEW's institutional and healthcare HVAC offerings.
• Viessmann Climate Solutions: Viessmann is a major German HVAC and heating manufacturer whose commercial ventilation and heat-recovery product line competes in the same institutional, healthcare and hospitality segments as SEW.
• WOLF GmbH (part of WOLF Group): WOLF is a long-established German heating, ventilation and climate systems manufacturer whose heating and HVAC segments overlap directly with SEW's heat recovery business for commercial and institutional buildings.
• Trox SE: Trox is a global leader in HVAC components including ventilation grilles, air-handling units and energy recovery modules, overlapping with SEW in commercial HVAC heat recovery applications.
• FläktGroup: FläktGroup is a European HVAC manufacturer providing air-handling units with energy recovery for commercial and industrial buildings, comparable to SEW's enterprise HVAC heat-recovery installations.

Direct peers

• Weiss Klimatechnik GmbH (Schunk Group): Weiss Klimatechnik specializes in precision climate control and energy-recovery air-handling systems for hospitals, research labs and cleanrooms, making it a strong direct peer in SEW's healthcare and research customer segments.
• Klingenburg GmbH: Klingenburg is a German specialist in high-efficiency heat and cold recovery wheels and rotors for HVAC systems, the closest direct competitor to SEW's GSWT-based heat recovery offerings in the DACH market.
• Heizomat Luft- und Klimatechnik: Heizomat is a German manufacturer of industrial and commercial heat-recovery ventilation solutions, overlapping with SEW's bespoke HVAC heat-recovery systems for German commercial customers.
• Menerga GmbH: Menerga is a German manufacturer of high-efficiency heat-recovery ventilation systems, particularly focused on swimming pool, commercial and industrial applications, directly competing with SEW's Kreislaufverbundsystem offering.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights7 records

Customer concentration

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Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about SEW