Diehl GmbH
Diehl GmbH is a German technical building equipment (TGA) provider founded in 1933, delivering integrated heating, ventilation, HVAC, refrigeration, sanitary, building automation, and renewable energy systems to industrial, commercial, public-sector, and residential customers across eight regional locations in Germany as part of the Apleona Wolfferts Group.
- Company typePrivate
- Founded1933
- HeadquartersKaiserslautern, Rhineland-Palatinate, Germany
- Headcount11–50
- GTM typeB2B and B2C
- OfferingServices
What Diehl GmbH does
Diehl GmbH is a German technical building equipment (TGA) provider founded in 1933 by Wilhelm Diehl in Baumholder, Rhineland-Palatinate. The company delivers full-scope technical building systems across heating (including heat pumps, CHP, fuel cells, solar thermal), ventilation and air conditioning, refrigeration, sanitary, MSR/building automation, electrical, photovoltaics, and swimming pool technology. It also provides energy consulting and TGA specialist planning. Following its acquisition by Apleona Wolfferts Group on May 22, 2024, Diehl GmbH now operates as part of Apleona's building technology division, with access to a network of over 2,000 specialists.
The company generates revenue primarily through project-based installation contracts for new construction and renovation, supplemented by recurring service and maintenance agreements. Its one-stop-shop model integrates all building technology trades under a single point of contact, serving industrial, commercial, public-sector, and private residential customers across eight regional locations in Rhineland-Palatinate, Hessen, and Thuringia. Pricing is project-specific and not publicly disclosed, consistent with B2B/B2G services contracting.
Post-acquisition, Diehl integrated three regional firms (Haag GmbH, HTS GmbH, and Albrecht-Diehl GmbH) in 2025, expanding both headcount (~600 employees including ~75 apprentices) and geographic reach. Recent strategic emphasis includes decarbonization services aligned with the German Energiewende, building automation/energy optimization, and workforce development through the newly opened Diehl-Akademie training facility in Baumholder (July 2026). The company holds GTGA, VDI, refrigeration technology, and PQ VOB pre-qualification certifications relevant to public-sector construction procurement.
Diehl GmbH firmographics
Firmographics- Name
- Diehl GmbH
- Legal name
- Diehl GmbH
- Website
- https://diehl-gmbh.de
- Company type
- Private
- Founded year
- 1933
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Diehl GmbH is a German technical building equipment (TGA) provider founded in 1933, delivering integrated heating, ventilation, HVAC, refrigeration, sanitary, building automation, and renewable energy systems to industrial, commercial, public-sector, and residential customers across eight regional locations in Germany as part of the Apleona Wolfferts Group.
- Ownership category
- akta.pro rank
Diehl GmbH industry classification
Industry- Product category
- Building Technology Services
- NAICS
- Plumbing, Heating, and Air-Conditioning Contractors (238220)
- SIC
- Refrigeration & Service Industry Machinery (3580)
- akta.pro primary industry
- HVAC & Refrigeration Contracting (IMAFALAB)
- akta.pro secondary industries
- New Construction HVAC Rough-In & Final Set (Residential/Light Commercial) (HSAOAGAL), HVAC Equipment (Heating, Cooling & Air Handling) (IMAHAKAB), Blast Chiller & Specialty Refrigeration Service (HSAOAJAJ)
Keywords
Where Diehl GmbH is headquartered
LocationHeadquarters
- HQ city
- Kaiserslautern, Rhineland-Palatinate
- HQ country
- Germany
- HQ region
- Europe
Offices8 records
Markets served
Diehl GmbH business model
Business model- GTM type
- B2B and B2C
- Offering type
- Services
Revenue model
- Technical Building Equipment Installation: Design, installation and execution of technical building systems for new construction and renovation projects for private, commercial, industrial and public sector customers
- Service and Maintenance: Ongoing service, maintenance and technical support for installed building systems ensuring reliable, energy-efficient and long-term operation
- Energy Consulting and TGA Planning: Project development, energy consulting and TGA specialist planning services for building projects
Go-to-market motion2 records
Distribution channels2 records
Marketing channels5 records
Diehl GmbH product offering
Product offeringCore offering
Diehl GmbH is a full-service provider of technical building equipment (Technische Gebäudeausrüstung, TGA) that designs, installs, and maintains integrated building systems across heating, ventilation, air conditioning, refrigeration, sanitary, electrical/MSR, building automation, and renewable energy trades. The company also offers specialized swimming pool technology, project development, TGA specialist planning, energy consulting, and ongoing service and maintenance for residential, commercial, industrial, and public-sector customers from a single contact point.
Product overview
Diehl Apleona Wolfferts is a full-service provider of technical building systems (TGA) offering integrated solutions across all building technology trades. The portfolio comprises core offerings in heating technology (heat pumps, CHP, fuel cells, solar thermal), ventilation and air conditioning, refrigeration, sanitary systems, MSR/building automation, photovoltaics, and swimming pool technology. The company provides end-to-end services from project development and TGA planning through execution to service and maintenance. The Diehl-Akademie serves as a supplementary training module for internal skills development.
Differentiator
Problem solved
Functional benefit
Quantifiable outcome
- 35 project agreements signed at first MINT-MatchUp networking event
Companies that use Diehl GmbH
Customer profileNamed customers6 records
Segments5 records
Diehl GmbH technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature3 records
Diehl GmbH partnerships and signals
Strategic signalPartnerships
One partnership is on record.
- Apleona Wolfferts GroupcoreApleona Wolfferts Group, a leading provider of building technology in Germany headquartered in Cologne, acquired Diehl Group on May 22, 2024. Diehl becomes part of Apleona's building technology division, strengthening the company's presence in technical building equipment and decarbonization services. Diehl Group had 550+ employees and 7 locations.
Scale indicators7 records
Recent moves8 records
Expansion highlights6 records
Diehl GmbH competitors and assessment
Company assessmentBroad incumbents
- ENGIE Deutschland: Large German building services and energy-efficiency operator with HVAC, refrigeration and facility-services capabilities. Operates much more broadly than Diehl but competes directly for the same municipal and commercial TGA contracts.
- Gegenbauer Gruppe: German facility management and building services group with technical building equipment and HVAC offerings. Overlaps with Diehl on commercial and public-sector TGA contracts, but at larger national scale.
- Dalkia Deutschland: Energy-services and heating-network specialist operating in Germany, focused on heating, cooling and energy-efficiency solutions for buildings. Comparable technology stack to Diehl but typically serves larger energy-network customers.
- WISAG: Major German facility services and building technology group offering HVAC, refrigeration, electrical and technical services. Competes with Diehl for commercial and industrial TGA projects across multiple German states.
Direct peers
- SBB Spezialbau + Brandschutz: German specialty contractor with HVAC, ventilation and technical building equipment services. Similar regional contractor profile and project-based delivery model to Diehl.
- Caverion Deutschland: Nordic/German full-service technical building equipment and HVAC contractor with design, installation and maintenance capabilities across heating, cooling, ventilation and automation. Closely matches Diehl's end-to-end TGA delivery model in the DACH region.
Regional players
- Otto Rüdrup GmbH: Mid-sized German TGA / HVAC contractor serving commercial and public-sector clients. Direct comparable in service scope and project-based revenue model.
- Kraft + Sohn Gebäudetechnik: Regional German TGA contractor offering heating, ventilation, sanitary and refrigeration services. Comparable scale and customer mix to Diehl, but with a different regional footprint.
Emerging players
- Stiebel Eltron Deutschland: German heat-pump and heating-technology manufacturer with growing service/installation network. Adjacent rather than direct overlap with Diehl, but competes for the same decarbonization retrofit projects and private-customer heating installations.
- Assemblin Germany (formerly Caverion assets): Nordic building technical services group expanding in Germany with HVAC, ventilation and electrical contracting capabilities. Comparable multi-trade TGA delivery model to Diehl.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks6 records
Key highlights7 records
Customer concentration
Diehl GmbH social profiles
Digital presenceDiehl GmbH compliance and trust
Trust signalCompliance4 records
Diehl GmbH financial estimates
Financial estimateRevenue estimate
Valuation estimate
Diehl GmbH leadership team
Management profileNumber of profiles
Diehl GmbH subsidiaries and ownership
Company hierarchySubsidiaries3 records
Diehl GmbH funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Diehl GmbH M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Diehl GmbH
What does Diehl GmbH do?
Diehl GmbH is a full-service provider of technical building equipment (Technische Gebäudeausrüstung, TGA) that designs, installs, and maintains integrated building systems across heating, ventilation, air conditioning, refrigeration, sanitary, electrical/MSR, building automation, and renewable energy trades. The company also offers specialized swimming pool technology, project development, TGA specialist planning, energy consulting, and ongoing service and maintenance for residential, commercial, industrial, and public-sector customers from a single contact point.
Is Diehl GmbH a public or private company?
Diehl GmbH is a private company. It is currently operating.
When was Diehl GmbH founded?
Diehl GmbH was founded in 1933. It employs 11 to 50 people.
Where is Diehl GmbH based?
Diehl GmbH is headquartered in Kaiserslautern, Rhineland-Palatinate, Germany, in the Europe region.
How does Diehl GmbH make money?
Three revenue lines are on record. Technical Building Equipment Installation is the primary driver. The others are service and Maintenance and energy Consulting and TGA Planning.
Who are Diehl GmbH's main competitors?
Broad incumbents on record are ENGIE Deutschland, Gegenbauer Gruppe, Dalkia Deutschland and WISAG. Direct peers are SBB Spezialbau + Brandschutz and Caverion Deutschland. Regional players are Otto Rüdrup GmbH and Kraft + Sohn Gebäudetechnik. Emerging players are Stiebel Eltron Deutschland and Assemblin Germany (formerly Caverion assets).
Does Diehl GmbH have an API?
No public API is recorded for Diehl GmbH.
What industry is Diehl GmbH in?
Diehl GmbH's product category is Building Technology Services. Its primary akta.pro industry code is IMAFALAB, HVAC & Refrigeration Contracting, with a secondary code of HSAOAGAL, New Construction HVAC Rough-In & Final Set (Residential/Light Commercial). Its NAICS code is 238220 and its SIC code is 3580.