What Celsia does

Celsia Inc. is a U.S.-based custom thermal management company headquartered in Harbeson, Delaware, specializing in passive two-phase cooling solutions for power-dense electronics operating in harsh environments. The company designs and manufactures heat pipes, one-piece and two-piece vapor chambers, thermosiphons, phase change material (PCM) heat sinks, thermal straps, methanol heat pipes, machined vapor chambers, loop heat pipes, and oscillating heat pipes (OHPs). Approximately 97% of Celsia's custom designs incorporate two-phase technology, protected by a portfolio of 30+ active patents covering proprietary manufacturing methods and device architectures. Beyond discrete two-phase devices, the company delivers integrated custom thermal assemblies combining these devices with extruded, zipper-fin, skived, and machined heat sinks. Every two-phase device is 100% tested prior to shipment, including 48-hour burn-in, helium leak checks, Qmax and thermal resistance validation, and dimensional inspection.

Celsia serves three primary verticals — defense electronics, aerospace systems, and telecommunications — with secondary exposure to industrial, medical, HPC, and test/measurement applications. The company operates a direct-engineering sales model in which customers submit project requirements through online quote forms and engage Celsia's thermal engineers from concept through validation and production. Pricing is quote-based and tied to custom specification, with multi-year program engagements typical for qualified defense and aerospace work. The firm is ISO 9001:2015 certified, ITAR registered, MIL-STD-810 validated, and RoHS/REACH compliant — credentials that gate entry into regulated defense and aerospace thermal management programs.

The company reports 91% customer retention with an 8-year average customer relationship and has completed thousands of designs since inception. Revenue, ownership, and capital structure are not publicly disclosed; Celsia is privately held with no parent company or institutional funding reported in the available data. In 2025, the company experienced a senior leadership transition with the loss of Marc Demars, who had served as VP of Marketing and Business Operations since 2007.

Name

Celsia

Legal name

Celsia Inc.

Website

https://celsiainc.com

Company type

Private

Founded year

2004

Operating status

Operating

Headcount range

101–250 employees

Short description

Celsia Inc. designs custom two-phase thermal management solutions—heat pipes, vapor chambers, thermosiphons, and PCM heat sinks—for defense, aerospace, and telecom programs. The U.S. firm holds 30+ active patents and reports 91% customer retention with 8-year average relationships.

Ownership category

akta.pro rank

Product category

Custom Thermal Management Solutions

NAICS

Heating Equipment (except Warm Air Furnaces) Manufacturing (333414), Ventilation, Heating, Air-Conditioning, and Commercial Refrigeration Equipment Manufacturing (33341)

SIC

Air-Cond & Warm Air Heatg Equip & Comm & Indl Refrig Equip (3585)

akta.pro primary industry

Thermal Management Components (Heat sinks, TIMs, fans/blowers, thermal pads) (IMAGAJAL)

akta.pro secondary industries

Heat Exchangers & Thermal Transfer Equipment (IMAHAKAC), Cooling & Thermal Solutions (Air/Liquid, fans, thermal paste) (HDACAGAF), Heat Transfer Equipment (Heat Exchangers, Boilers, Condensers) (IMAHAEAC)

Keywords

• Custom heat sinks
• Two-phase cooling
• Thermal management solutions
• Vapor chamber manufacturing
• Heat pipe engineering

Headquarters

HQ city

Santa Clara

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Custom thermal solutions manufacturing: Celsia designs and manufactures custom heat sinks and two-phase thermal assemblies to order, serving aerospace, defense, and telecom programs with low-to-mid volume production. Revenue is generated through custom engineering, prototyping, and production orders. The company operates a controlled supply chain with full material traceability and 100% testing on every two-phase device.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

Celsia designs and manufactures custom heat sinks and advanced two-phase thermal systems in the United States. The company engineers the complete thermal path—from source spreading through transport to ambient rejection—using heat pipes, vapor chambers, thermosiphons, phase change materials, and integrated thermal assemblies. Its products serve high-reliability electronics applications in aerospace, defense, telecommunications, and industrial markets.

Product overview

Celsia is a U.S.-based custom thermal management company specializing in two-phase cooling solutions for demanding electronics applications. The product portfolio centers on passive two-phase thermal devices including custom heat pipes (with sintered, grooved, mesh, or braided wicks), 1-piece and 2-piece vapor chambers, thermosiphons, and phase change material (PCM) heat sinks. These core thermal components are combined with various heat sink fin types (extruded, zipper fin, skived, machined, bonded) into complete custom thermal assemblies. Specialty products include methanol/acetone heat pipes for sub-zero operation, machined vapor chambers for complex geometries, loop heat pipes for aerospace routing, and oscillating heat pipes for long-distance transport. The company also offers thermal straps and full integrated thermal assemblies with mounting hardware and TIM for defense, aerospace, telecom, and industrial applications. Celsia provides design tools including CAD model downloads, thermal calculators, and technical resources alongside manufacturing and testing services.

Differentiator

Problem solved

Functional benefit

Products and services

• Custom Heat Pipes Application-tuned heat pipes with customizable wall thickness, wick thickness, porosity, permeability, and fluid loading for thermal transport across distance and orientation. Designed for defense, aerospace, telecom, and industrial electronics.
• 1-Piece Vapor Chambers Lower-cost vapor chamber devices allowing Z-axis bending in dimensions up to 109mm wide and 5mm thick, formed from single copper tubes. Used for heat spreading in high-heat-flux applications.
• 2-Piece Vapor Chambers Stamped vapor chambers formable into any shape along XY axes with options for embossments, through-holes, and variable wicks for high heat flux applications.
• Thermosiphons Gravity-assisted two-phase devices for high-capacity passive heat transport over longer distances with minimal thermal resistance, using condensate return under gravity.
• Phase Change Material (PCM) Heat Sinks Thermal storage solutions using paraffin wax to manage transient spikes in ambient temperature or device thermal load through latent heat absorption and release.
• Thermal Straps Flexible conductive links made from copper, aluminum, or composite materials for heat transfer between components in vibration-prone or movement-exposed systems.
• Methanol Heat Pipes Alternative heat pipes using methanol as working fluid for operation below 0°C with freeze points down to -75°C, used in cold-start and sub-zero applications.
• Machined Vapor Chambers CNC-machined vapor chambers for complex multi-axis shapes, able to attach to multiple heat sources on different planes with high clamping pressure tolerance.
• Loop Heat Pipes Passive two-phase devices with separate evaporator and condenser components connected by fluid lines, enabling complex routing over longer distances for aerospace and defense applications.
• Oscillating Heat Pipes (OHPs) Pulsating heat pipes using serpentine design with narrow 1-3mm diameter channels forming liquid slugs and vapor bubbles for long-distance heat transport against gravity.
• Extruded Heat Sinks Cost-effective heat sink manufacturing for natural convection applications using extrusion process.
• Zipper Fin Heat Sinks High fin density heat sinks for controlled airflow environments with thin, densely packed fins optimized for integration with two-phase devices.
• Skived Fin Heat Sinks

Quantifiable outcome

• 97% of custom heat sink designs are two-phase based, covering heat pipes, vapor chambers, thermosiphons, and PCMs
• +3 more outcomes

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature8 records

Scale indicators6 records

Recent moves6 records

Expansion highlights4 records

Broad incumbents

• Wakefield-Vette: Established thermal management manufacturer producing heat sinks, liquid cold plates, and thermal interface materials for power electronics, telecom, and industrial — competes with Celsia in extruded and bonded fin heat sinks across overlapping industrial and telecom accounts.
• Mersen: Global manufacturer of thermal management solutions including heat sinks, cold plates, and bus bars for power electronics, aerospace, and EV markets — broader portfolio but competes in custom thermal assemblies for power-dense electronics.
• Boyd Corporation: Large thermal management incumbent formed by the merger of Aavid Thermalloy and Boyd, offering heat sinks, liquid cooling, and thermal interface materials across aerospace, defense, EV, and electronics — broader portfolio but overlapping with Celsia's custom heat sink business.

Direct peers

• Radian Thermal Products: Custom thermal solutions manufacturer producing heat pipes, vapor chambers, and heat sink assemblies for aerospace, defense, and high-reliability electronics — directly comparable niche custom engineering model serving similar customer verticals.
• Advanced Cooling Technologies: Direct peer — Pennsylvania-based custom two-phase thermal solutions manufacturer offering heat pipes, vapor chambers, thermosiphons, and loop heat pipes for aerospace, defense, and electronics applications, closely aligned with Celsia's product portfolio and customer verticals.
• Lytron: Manufacturer of cold plates, heat exchangers, and liquid cooling systems for aerospace, defense, and industrial electronics — adjacent thermal management portfolio with overlapping customer base in defense and high-reliability electronics cooling.
• Thermotek: Custom thermal management company specializing in liquid cooling, thermoelectric, and two-phase solutions for medical, industrial, and defense applications — overlapping custom engineering approach and defense/industrial customer segments.

Others

• Alphacool: Manufacturer of liquid cooling components and thermal solutions primarily for PC, gaming, and enthusiast markets — adjacent thermal management player representing the consumer/PC alternative cooling ecosystem that touches Celsia's thermal technology base.

Regional players

• Asia Vital Components (AVC): Taiwan-based manufacturer of heat sinks, vapor chambers, and thermal modules primarily serving PC, server, and consumer electronics markets — regional player with overlapping two-phase technology capability but different end-market focus than Celsia's defense/aerospace specialization.

Emerging players

• CoolIT Systems: Direct liquid cooling specialist for data centers, AI/HPC, and high-performance computing — emerging player representing the alternative cooling architecture that could displace passive two-phase heat sinks in extreme-density applications.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/@celsiainc.9819
• LinkedInlinkedin.com/company/celsia-inc

Compliance6 records

Revenue estimate

Valuation estimate

Number of profiles

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 Celsia