ACT is proud to support a better tomorrow through renewable energy. Our small part is to develop innovative solutions that enable technologies to operate more efficiently and effectively.

ACT is a leading provider of proven, fielded hardware for the energy sector. In addition to our commercial customers, ACT’s engineering teams have worked on large impactful energy-related programs for NASA and the Department of Energy (DOE) organizations including NREL (Nuclear Renewable Energy Lab), ARPA-E (Advanced Research Program Agency-Energy), and INEL (Idaho National Engineering Lab). These projects span a wide range, including Wind Energy, Solar, Fossil Fuel Power Plants, and Nuclear Fission for Terrestrial and Lunar/Martian power.



Since 2000, electricity generation from wind energy has increased nearly 100-fold as nations across the globe invest in technology and implementation. Wind energy is critically important technology in the fight to eliminate CO2 emissions and as technology and supply chain continue to innovate, it should continue to drive down the levelized cost of electricity. On-shore and off-shore wind turbines have continuously evolved, scaling physical size, creating higher efficiency, and generating more usable energy. These trends are driving a need for higher-performance thermal management solutions. Wind turbines operate very similarly to a traditional fan in your house, except in reverse. Where fans use electricity to turn the blades and create airflow, wind turbines harness the wind to turn the turbine blades around a rotor, spinning a generator that can create electricity. From a thermal perspective, there are a lot of moving parts, friction forces, and control electronics that create heat in the system and must be properly and efficiently managed.

Understanding the heat sources is the first step in developing an appropriate thermal management architecture for wind turbines. With many different sources and physical locations of heat generating components, it’s important to study the entire architecture and take a system level thermal approach to drive out inefficiencies and provide an optimized performance for the wind turbine manufacturer and end users. Critical areas in designing a full thermal management system that ACT has seen from our customers include:  

  • Gear and hydraulic oil cooling
  • Generator waste heat
  • Power Electronics cooling
  • Energy storage thermal management

Like most industries, the waste heat levels, form factors, etc. will drive the thermal technology selection; however, in the energy sector and especially upscale wind turbine applications there is a premium for high reliability, maintenance free, and low energy consumption solutions. This desire tends to drive designers to passive thermal management solutions. ACT’s Loop Thermosyphon Technology is 100% passive operation and highly scalable with fielded solutions ranging from 100 Watts to 100,000 Watts of waste heat rejection.  The maintenance free technology extends the life of the turbine by reducing thermal wear and reduces the parasitic energy losses by removing pumps and fans in the system.

Loop Thermosyphon on Nacelle
Loop Thermosyphons for wind turbine nacelle cooling.


Sealed Enclosure Coolers keep technologies related to ground control clean, cool, and operational. In hot and rugged environments, potential contaminants, or waste heat, risk causing damage to critical technology and machinery. ACT’s Sealed Enclosure Cooling line of units are NEMA rated, ensuring a cut down on maintenance caused by hazardous material compromising protective cabinets.


One of the greatest challenges within the energy industry is power storage yet it is critical in providing energy to locations in demand.  Likewise converting the harvested energy into usable electricity distributed into the Grid requires sophisticated power conversion through power electronics such as inverters. These energy storage and power electronic systems require enhanced thermal management to optimize the efficiency and life while reducing the thermal energy losses.  As technology advances, the power systems increase in size, speed, intelligence, complexity, and relatively: waste heat. The passive and hybrid thermal management technologies developed by ACT offer efficient thermal control with minimal energy consumption.

Grid-Tie Power Conversion Cooling: Cooling Power Electronics

ACT’s Pumped Two-Phase (P2P) Cooling products and solutions use a non-corrosive and non-electrically-conductive fluid that vaporizes and cools hot surfaces on contact. These products are ideal for cooling high-power electronics where heat loads have increased to a level beyond what traditional air and water cooling systems can effectively manage.  Since the pumped two-phase technology leverages the latent heat of vaporization, it can pull more heat per molecule of fluid than typical single-phase cooling.  This means it can handle the high heat flux from IGBTs and Inverters without increasing fluid flow and therefore minimalizing pump size and parasitic energy losses.

Pumped Two-phase Cooling Benefits
  • Up to 85% reduction in pumping power consumption compared to single phase cooling
  • Dielectric working fluid to avoid catastrophic failure in the event of a leak
  • Hot Swappable connections to reduce service down time

Battery Energy Storage Systems (BESS)

ACT’s sub-ambient product line out of York Pennsylvania is ideal for battery thermal management. Batteries require a tight temperature range to operate efficiently.  ACT’s hybrid environmental control units (h-ECUs) leverage vapor compression to operate below the ambient temperature and semi-passive two-phase heat transfer for above ambient support.  This provides cooling for the BESS in hot ambient environments and an energy efficient two-phase operation in a low ambient environment.  When coupled with a well-designed thermal management system the ECU will provide thermal stability to the BESS which will reduce the degradation of an under performing cell and enhance the energy storage efficiency. The key benefits of the h-ECU and thermal management system include:

  • Cooling in hot ambient environments
  • Temperature stability
  • Energy efficiency in mild-ambient environments
  • Full thermal control


Phase change material (PCM) heat sinks can improve the thermal performance of power plants by storing thermal energy. This works by storing the low-grade heat during the day and rejecting the heat at night when the ambient temperature is cooler. ACT’s engineers explored the use of salt hydrate Phase Change Material (PCM) with ARPA-E.

Graphic depicting the flow of a PCM heat sink


ACT designs and manufactures both off-the-shelf and custom Sealed Enclosure Coolers designed to dissipate waste heat caused by electronics operating in protective cabinets.

Liquid chillers and heat exchangers are proven when it comes to keeping critical equipment at optimum operating temperatures. With fielded heritage in dozens of installments, these units deliver superior results for high-intensity workloads. Projects such as radar and missile defenses rely on ACT’s chiller units to keep their systems cool and their personnel safe. Thanks to their rugged design and build quality, liquid chillers and heat exchangers can support operations anywhere in the world.


A higher demand for safe clean energy to replace fossil fuel leads to new innovations in nuclear reactor designs and thermal management techniques. Many Small Modular Reactors (SMRs) and Micro-reactors leverage heat pipe technology to passively pull heat from the reactor core to the heat exchanger for the power conversion system. Advanced Cooling Technologies, Inc. has been working to develop the high-temperature heat pipes used in these reactors for both space and terrestrial applications.

Nuclear – Space

ACT is developing thermal solutions for surface-based power and both nuclear electric and nuclear thermal propulsion (NEP, NTP).  The space applications require high temperature heat pipe with wicks for micro-gravity liquid return.  ACT has been working with NASA to qualify and enhance our high-temperature wicked heat pipes.  Once the heat has been removed from the reactor core and converted to electric energy the waste heat must also be managed.  Here ACT has developed both passive and active solutions to remove heat from the cold end. This technology is highlighted in our application spotlight below.


High temp heat pipe glowing

In collaboration with the NASA Glenn Research Center on the Kilopower Project, Advanced Cooling Technologies, Inc. (ACT) designed and fabricated hybrid screen-groove titanium water heat pipes to dissipate waste heat from nuclear power systems to the radiators, as solely grooved wicks are insufficient for the varied operating environments seen in space.

Nuclear – Terrestrial

Terrestrial applications require strict safety regulations.  The passive nature of the heat pipe makes it ideal for the previously mentioned micro-reactors.  Heat pipes allow nuclear reactors to adapt to changing temperatures dynamically. These high temperature heat pipes are used to pull heat from the reactor core and distribute to the heat exchanger/generator.  ACT has delivered high temperature thermosyphons with wicked evaporators that leverage gravity for the liquid return to the nuclear industry. Like space, work is being done to develop fully wicked heat pipes to support horizontally oriented micro-reactors. 

Cold end reactor thermal management technologies are being developed to offer redundant cooling and passive thermal control. ACT has experience working and delivering thermal management solutions for the cold end temperature range.


High-temperature heat pipes are used to passively and safely transfer the heat (fission power generated) from the reactor core to the intermediate coolant.

ACT’s Alkaline Metal Heat Pipes have the capability to operate up to 1100̊C. They are, therefore; ideal for removing the heat from the reactor core – typically measured around 600̊C – at the highest temperature possible in the most efficient manner.


Fossil fuel is a non-renewable form of energy sourced from oil, coal, and natural gas. For decades, fossil fuels are extracted from the earth via drilling or mining, burnt to produce electricity, or refined to use as a fuel for heat or transportation. Drilling and mining sites are notorious for their rugged work environments with a risk for debris to clog or damage electronics and machinery. Enclosures protect valuable equipment from debris but are prone to overheating due to extreme ambient temperatures or waste heat created by machinery and electronics. Custom, specialized cooling systems are often needed to maintain the longevity of industrial equipment housed in these protective enclosures.

Technology Spotlight

Funded by DOE and ARPA-E, Swiss-roll combustor is an innovative, enclosed combustion control device (ECD) that can achieve > 99.5% methane destruction and removal efficiency (DRE) for small and low-pressure emission sources (e.g. tank vent, pipeline blow down).  The technology provides a perfect solution for the recently updated EPA regulatory (e.g. OOOOb/c, Subpart W). 

Swiss-roll Features

  • Wide flow range (from < 1 MSCFD to > 10 MSCFD) 
  • Made by high temperature ceramic composite material (operation temperature > 1350C) with advanced low-cost manufacturing process
  • Ultra-high methane and VOCs DRE (> 99.5%)
  • Ultra-compact (combustor size: 1’ cube), whole system is trailer transportable
  • Scalable via modular design
  • No visible flame, low NOx, no soot/ smoke

Technology Spotlight

Unlike commercial air conditioners, Environmental Control Units (ECUs) are designed to be rugged. They must survive rough terrain and remain operational at the extreme temperatures and conditions to which they will be exposed. ECUs are mobile, capable, durable solutions for environmental control needs.


Harnessing the power of the sun is critical to meeting the world’s energy demands. A multitude of different technologies exists to convert solar energy into electric power or heat. Popular technologies include solar water heaters, concentrated photovoltaics, and heat-engine-based systems. All of these solar applications require appropriate thermal management to maintain performance and cost goals. ACT has developed technologies to aid in the thermal management of all of these solar applications.


One of the most obvious challenges to Solar-Electric power conversion is that the sun doesn’t shine at night, so energy storage is required. ACT has conceived of and has begun to develop a “Dark” Photovoltaic Cell that generates power when exposed to a colder radiative heat sink. Possible heat sink options include cold clear night skies experienced in desert areas, as well as deep space heat sinks for spacecraft power systems.


A loop thermosyphon is a type of high-power heat pipe that works in many cooling applications (computers, HVAC, electronics, etc.).


ACT has experience designing heat pipe heat sinks to spread the heat from the solar cell and dissipate the heat through finned heat sinks. The benefit of this solution is no moving parts, resulting in the high reliability typical of traditional solar panels.

Heat engines, such as Stirling engines, thermoacoustic generators, and thermionic converters, are often used to generate electricity from solar energy. In these processes, solar energy is concentrated onto a solar receiver which absorbs the solar energy as heat. Performance is improved by using ACT’s high-temperature heat pipes to acquire the high-temperature heat from the receiver and transfer the heat isothermally to the hot side of the engine with minimal losses.


ACT designs and manufactures pumped and passive Energy Recovery Heat Pipe Heat Exchanger Solutions for the industrial and commercial markets utilizing the natural passive properties of copper water heat pipes to create an energy-efficient HVAC solution. ACT has engineered custom HVAC systems for over 20 years. These systems have proven to outperform traditional HVAC solutions that many schools and universities have turned to for decades. These systems have zero-cross air contamination as well as a typical payback period of 2-3 years with an expected 20-year lifetime. ACT’s HVAC solutions can be engineered across large distances and most systems are not limited by geometric configurations. Replace traditional energy or enthalpy wheel solutions with ACT’s custom HVAC energy recovery systems.


BTU Company, a Chicago Illinois area environmental control solutions provider, a representative of ACT is set to build eight independent Split-Pump assisted Air-to-Air Heat Exchangers for HVAC system upgrades at the Illinois State University. The upgrades save Illinois State University 40% in energy costs.


Wrap-Around Heat Pipe Heat Exchanger (WAHX) systems can be designed for all major air handler units (AHU) OEMs. Control options, corrosion-resistant coatings, and enhanced dehumidification are all benefits of the Wrap-Around HVAC system. When retrofitting existing HVAC systems, ACT can ship a pre-engineered unit, fully charged and ready to install. ACT offers onsite installation of HVAC systems or units can be factory installed. Typical HVAC design-build/install costs are recouped in a 1-2 year payback period.

Wrap-Around Heat pipe Heat Exchanger
WAHX Split Loop Thermosyphon
Split Loop Thermosyphon WAHX
ACT Thermal Passive Valve


Air-to-Air Energy Recovery Heat Pipe Heat Exchanger (AAHX) is a counter-flow heat exchanger-energy recovery system that features ACT’s high-performance, highly-reliable copper-water heat pipes. These systems save energy by pre-cooling or pre-heating your incoming building supply air and save you money on utility and energy costs.

Air-to-Air Heat Pipe HX
Air-to-Air Heat Pipe Heat Exchanger Installation Orientation
AAHX Airflow Diagram
AAHX Passive Split loop options
Pump Assisted AAHX Infographic
AAHX Pump Assisted Split Loop production
AAHX Pump Assisted

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