Process Overview

Thermoelectric heating and cooling is a precision temperature control technology that transfers heat electronically rather than by using compressors, refrigerants, or combustion. By applying direct current (DC) to thermoelectric modules, the same device can either absorb heat from a process or deliver heat to it simply by reversing the direction of the electrical current.

This unique capability allows a single thermoelectric system to provide both heating and cooling with exceptional precision, making it an ideal solution for applications requiring accurate temperature control, rapid thermal response, compact equipment, and long-term reliability.

Today, thermoelectric temperature control systems are widely used throughout the semiconductor, pharmaceutical, biotechnology, analytical instrumentation, laboratory, medical device, photonics, aerospace, defense, and advanced manufacturing industries.

Applied Integrated Systems (AIS) designs and manufactures two complementary families of thermoelectric temperature control systems:

• Pelti-Therm™ Recirculating Thermoelectric Heater/Chiller Systems for conventional heat transfer fluids such as water/glycol mixtures, silicone fluids, alcohols, oils, and other industrial coolants.

• Kool-Pure™ High-Purity Thermoelectric Heater/Chiller Systems for semiconductor and other contamination-sensitive applications requiring chemically inert fluoropolymer (PFA/Teflon®) flow paths.

  
  

Together, these product families allow AIS to provide precision thermoelectric heating and cooling solutions across a wide range of industrial and high-purity process applications.

At a Glance

What Is Thermoelectric Heating & Cooling?

Thermoelectric heating and cooling uses semiconductor devices known as thermoelectric modules to transfer heat electronically from one location to another.

Unlike conventional heating systems that generate heat through electrical resistance or combustion, thermoelectric systems move heat using the Peltier Effect.

When direct current passes through a thermoelectric module:

• One side absorbs heat.

• The opposite side releases heat.

  
  

Simply reversing the polarity of the electrical current reverses the direction of heat flow, allowing the same thermoelectric module to switch seamlessly between heating and cooling.

This bidirectional operation enables a single thermoelectric system to maintain precise process temperatures without separate heating and cooling equipment.

How the Peltier Effect Works

A thermoelectric module consists of numerous pairs of P-type and N-type semiconductor elements electrically connected in series and thermally connected in parallel.

When electrical current flows through the module:

• Heat is absorbed from the process.

• Heat is transported through the semiconductor junctions.

• Heat is rejected on the opposite side of the module.

  
  

The amount of heat transferred depends upon:

• Applied current

• Module design

• Heat load

• Hot-side temperature

• Cold-side temperature

• Heat rejection efficiency

  
  

Because heat transfer is entirely electronic, thermoelectric systems respond rapidly to changing process conditions while providing smooth, highly stable temperature control.

A Complete Thermoelectric System Is More Than a Thermoelectric Module

One of the most common misconceptions is that a thermoelectric module alone is a complete temperature control system.

In reality, the thermoelectric module is only one component within a much larger engineered system.

A precision thermoelectric heater/chiller typically integrates:

• Thermoelectric heating and cooling modules

• Heat exchangers

• Fluid circulation pumps

• Reservoirs

• High-accuracy temperature sensors

• PID temperature controllers

• Power electronics

• Safety interlocks

• Communications

• Mechanical packaging

  
  

The overall performance of the system depends on how effectively these components are engineered to work together.

Why System Engineering Matters

A thermoelectric module transfers heat—it does not regulate process temperature by itself.

Achieving stable, repeatable temperature control requires careful engineering of the complete thermal system.

Important design considerations include:

Heat Load

The system must provide sufficient heating and cooling capacity under all operating conditions.

Heat Rejection

Every watt of heat transferred must ultimately be removed through properly designed air-cooled or liquid-cooled heat exchangers.

Fluid Circulation

Pump selection directly affects response time, temperature uniformity, pressure drop, and overall system performance.

Temperature Measurement

High-accuracy RTDs and properly positioned sensors provide the feedback required for precise PID temperature control.

Control Algorithms

Optimized PID tuning minimizes overshoot while maintaining excellent temperature stability under changing process conditions.

Mechanical Design

Reservoir volume, plumbing configuration, insulation, enclosure design, and serviceability all influence long-term system reliability.

Two Thermoelectric Product Families for Different Applications

Because no single thermoelectric system is ideal for every application, Applied Integrated Systems has developed two complementary product families optimized for different process requirements.

Pelti-Therm™ Recirculating Thermoelectric Heater/Chiller Systems

Pelti-Therm™ systems are designed for precision temperature control using conventional heat transfer fluids, including:

• Water/glycol mixtures

• Silicone fluids

• Industrial coolants

• Other compatible heat transfer fluids

  
  

Typical applications include:

• Medical devices

• Pharmaceutical equipment

• Laboratory instrumentation

• Environmental chambers

• Battery testing

• Laser cooling

• Analytical instruments

• Industrial OEM equipment

• Research laboratories

  
  

Pelti-Therm™ systems provide precise bidirectional heating and cooling, configurable heating and cooling capacities, compact installation, and application-specific flexibility for a wide variety of industrial and scientific applications.

Kool-Pure™ High-Purity Thermoelectric Heater/Chiller Systems

Kool-Pure™ systems are specifically engineered for applications requiring high-purity fluoropolymer flow paths.

Typical process fluids include:

• Ultra-Pure Water (UPW)

• Deionized (DI) Water

• Sulfuric Acid

• Hydrochloric Acid

• Hydrofluoric Acid

• SC-1

• SC-2

• SPM

• Solvents (non-flammable)

• Other corrosive process chemicals

  
  

Unlike conventional fluid circuits that may introduce contamination, Kool-Pure™ systems utilize chemically inert PFA/Teflon® wetted surfaces to help preserve fluid purity while delivering highly accurate thermoelectric heating and cooling.

Typical applications include:

• Semiconductor wet benches

• Chemical delivery systems

• Chemical recirculation loops

• Wafer cleaning

• Process development

• High-purity chemical processing

Benefits of Thermoelectric Heating & Cooling Systems

Properly engineered thermoelectric systems offer several advantages for precision temperature control.

Heating and Cooling in One System

The same thermoelectric modules provide both heating and cooling by simply reversing the electrical current.

Excellent Temperature Stability

Thermoelectric systems are capable of maintaining highly stable temperatures for demanding laboratory, semiconductor, and industrial processes.

Refrigerant-Free Operation

Because thermoelectric systems transfer heat electronically, they operate without conventional refrigerants while supporting environmentally responsible temperature control.

Compact Equipment

The absence of compressors allows compact system integration into OEM equipment and laboratory instruments.

Quiet Operation

With no compressors and no moving mechanical parts within the thermoelectric modules, system noise is minimized.

High Reliability

Properly engineered thermoelectric systems provide years of dependable service with minimal maintenance.

Application-Specific Flexibility

Heating capacity, cooling capacity, pumps, reservoirs, communications, electrical configurations, and plumbing layouts can all be configured around the customer's requirements.

The AIS Engineering Approach

Applied Integrated Systems believes that precision temperature control systems should be engineered around the customer's process rather than forcing the process to adapt to standard catalog equipment.

Whether the application requires a Pelti-Therm™ system for conventional heat transfer fluids or a Kool-Pure™ system for high-purity semiconductor chemistries, every project begins with understanding the customer's operating requirements.

AIS engineers routinely evaluate:

• Heating capacity

• Cooling capacity

• Temperature range

• Temperature stability

• Heat load

• Flow rate

• Fluid compatibility

• Reservoir size

• Pump selection

• Control architecture

• Communications

• Installation footprint

• Electrical requirements

  
  

Rather than integrating off-the-shelf components into a fixed package, AIS configures complete thermoelectric temperature control systems around each application's specific performance objectives.

These application-specific configurations are developed and provided at no additional engineering charge, allowing customers to obtain a thermoelectric heating and cooling system optimized for their application without incurring the engineering fees commonly associated with custom equipment.

This collaborative engineering philosophy enables OEMs, equipment manufacturers, and process engineers to integrate precision temperature control into their systems while maintaining flexibility for future design enhancements.

Engineering Design Checklist

When specifying a thermoelectric heating and cooling system, engineers should consider:

Process Requirements

• Required operating temperature

• Heating capacity

• Cooling capacity

• Temperature stability

• Heat load

  
  

Fluid System

• Heat transfer fluid or process chemistry

• Flow rate

• Pressure requirements

• Reservoir volume

• Plumbing connections

• Material compatibility

  
  

Controls

• Sensor accuracy

• PID control

• Communication protocols

• Alarm functions

• Safety interlocks

  
  

Mechanical Integration

• Installation footprint

• Heat rejection method

• Electrical service

• Future scalability

  
  

Frequently Asked Questions

Can thermoelectric systems both heat and cool?

Yes. By reversing the electrical current, the same thermoelectric modules provide either heating or cooling.

What is the difference between Pelti-Therm™ and Kool-Pure™?

Both use thermoelectric technology, but they are optimized for different applications. Pelti-Therm™ systems are designed for conventional heat transfer fluids such as water/glycol mixtures and other industrial coolants. Kool-Pure™ systems are engineered with high-purity fluoropolymer (PFA/Teflon®) flow paths for semiconductor process chemicals, ultra-pure water, and other contamination-sensitive applications.

Can thermoelectric systems be customized?

Yes. AIS routinely configures heating capacity, cooling capacity, pumps, reservoirs, communications, plumbing, electrical configurations, and controls around each customer's application. This customization is provided at no additional engineering charge.

Continue the Conversation with an AIS Engineer

Selecting the right thermoelectric heating and cooling system involves much more than choosing a heating or cooling capacity. The most effective solution depends on understanding the complete application—including temperature stability, heat load, fluid compatibility, control requirements, installation constraints, and long-term performance goals.

Applied Integrated Systems works directly with OEMs, semiconductor equipment manufacturers, laboratory instrument designers, medical device companies, pharmaceutical manufacturers, and industrial process engineers to develop application-specific thermoelectric temperature control systems.

Whether your application is best served by a Pelti-Therm™ Recirculating Thermoelectric Heater/Chiller System or a Kool-Pure™ High-Purity Thermoelectric Heater/Chiller System, our engineering team is ready to help configure the optimal solution for your process.

Explore the AIS thermoelectric product portfolio or request a customized quote to discuss your application with one of our thermal engineers. The system will be configured to meet your specific requirements at no additional engineering charge.