Thermal Management Assemblies
Liquid To Liquid Assemblies
A liquid to liquid assembly puts thermoelectric modules between two liquid heat exchangers, so a circulating process fluid can be cooled or heated against a second loop.
Product Overview
How This Configuration Works
A liquid to liquid assembly puts thermoelectric modules between two liquid heat exchangers, so a circulating process fluid can be cooled or heated against a second loop.
This is the configuration behind small recirculating chillers and temperature conditioned fluid supplies, where a compressor based chiller would be oversized, too noisy or unable to hold a stable set point at low cooling powers.
Because the same module reverses, one unit can hold a fluid above or below the source temperature, which is useful for laboratory and process equipment that has to work in both directions.
Key Benefits
Why This Configuration
Stable Fluid Set Point
Thermoelectric control modulates smoothly, so the fluid temperature does not swing the way a cycling compressor makes it swing.
Compact And Silent
No compressor, no refrigerant charge and no service intervals for the thermoelectric part of the system.
Bidirectional
The same assembly cools or heats the process fluid by reversing module polarity.
Who It Is For
Who Uses It
- Laboratory instrument designers building small recirculating chillers
- Process equipment makers conditioning a fluid line
- Analytical instrument teams that need a fluid held to a tight tolerance
- Semiconductor and optics equipment builders needing quiet, vibration free fluid control
- OEMs replacing an oversized compressor chiller at low cooling powers
Problems It Solves
What It Solves
- A compressor chiller is oversized for a few hundred watts of duty
- Fluid temperature swings because a compressor cycles on and off
- Vibration and noise from a compressor disturb the measurement
- Refrigerant handling and certification are unwanted in the product
- The same fluid loop must sometimes be heated and sometimes cooled
Technical Features
Design Considerations
Flow On Both Sides
Both loops need adequate flow. The hot side loop must carry the load plus the module electrical input.
Approach Temperature
The achievable fluid temperature is set by the source loop temperature plus the exchanger approach.
Pump Selection
Pump head and flow are part of the thermal design, not an afterthought.
Corrosion And Fouling
Exchanger material, coolant additives and filtration decide long term performance.
Thermal Mass
Loop volume smooths the set point but slows the response. Size it deliberately.
Freeze Protection
If the cold loop can go below zero, the fluid and the exchanger have to tolerate it.
Specifications
Specification
Assemblies are built around your duty point using modules from our own catalogue.
What We Need To Configure An Assembly
- Heat load to remove, in watts, and the temperature it must be held at
- Ambient temperature range and the worst case you must still work in
- Enclosure or process volume, and how the cold side is coupled to it
- Available supply voltage and current, and whether control is on and off or proportional
- Space envelope, mounting orientation and any ingress protection requirement
- Flow rate and coolant type, for any liquid coupled configuration
Assemblies are configured per project from our module catalogue rather than sold as fixed catalogue items, so capacity and dimensions are confirmed at quotation.
Catalogue Notes
| Data reference | All catalogue values are measured at a hot side temperature Th = 30 °C |
| Flatness | ±0.05 mm |
| Height tolerance | ±0.2 mm |
| Maximum compressive load | 1 MPa |
| Lead wire | 150 mm as default, other lengths and terminations on request |
| Sealing | Silicone gel seal. Specify if you do not want the module sealed |
Symbol Definitions
| Imax | Maximum input current in amperes at Qc = 0 and ΔTmax |
| Vmax | Maximum DC input voltage in volts at Qc = 0 and Imax |
| ΔTmax | Maximum temperature differential in °C at Qc = 0 and Imax |
| QcMax | Maximum heat pumping capacity in watts at Imax and ΔT = 0 |
| Th | Temperature of the hot side during operation |
| Tc | Temperature of the cold side during operation |
Materials And Construction
What Goes Into The Assembly
| Modules | TEC1 ceramic or TEA1 aluminium substrate modules from our own production |
| Interface | Thermal grease or graphite sheet, selected for the clamping method |
| Sealing | Silicone gel sealed modules, with condensate management on the cold side |
| Control | Temperature controller and thermistor, supplied as accessories |
| Test | Modules 100 % tested before assembly, assemblies functionally tested |
| Specification | Issued per project, to be confirmed at quotation |
Manufacturing Process
From Ingot To Finished Module
- Duty point review: heat load, set point, ambient and control method
- Module selection from the TEC1, TEA1 or TES1 catalogue
- Cold side and hot side exchanger sizing around the selected module
- Interface, sealing and condensation management
- Electrical design: supply, controller and sensor arrangement
- Build, test and documentation before shipment
Quality Control
Every Module Is Tested Before It Leaves The Line
Quality control runs from raw material procurement through crystal growth, pellet selection and module assembly to the dispatch of the finished product. All products are 100 % tested and inspected using test equipment sourced from an American thermoelectric company.
ISO 9001
Quality management system certified
SGS
European Union certification held by the manufacturing company
RoHS
All thermoelectric modules are RoHS compliant
100 % tested
Every module is tested and inspected before dispatch
Customization Options
Configured, Not Catalogued
Every assembly is put together from our module range around the load you actually have.
Capacity
Module count and size chosen for your heat load and delta-T.
Supply And Control
Built for the voltage you have, with proportional or on and off control.
Mechanical Integration
Mounting, orientation, sealing and service access designed in.
Comparison With Other Products
Compared With The Other Configurations
| Configuration | Cold side | Hot side | Best when |
|---|---|---|---|
| Air to air | Air | Air | A sealed enclosure has to be cooled below ambient with no plumbing |
| Air to liquid | Air | Liquid | Heat must leave the area entirely, or ambient air is hot or dirty |
| Liquid to liquid | Liquid | Liquid | A circulating fluid loop needs to be conditioned |
| Plate to plate | Conduction | Conduction | The load bolts straight to a cold plate and space is tight |
Use Guide
Making It Work In The Field
- Specify both loops. A liquid to liquid unit is only as good as the weaker of the two circuits.
- Confirm the source loop temperature, because it sets the baseline the assembly works from.
- Design pump flow and head together with the exchanger, not after it.
- Filter the fluid. Fouled micro channels are the most common cause of gradual performance loss.
- Add flow interlocks so the modules cannot run dry on either side.
- Allow for expansion and freeze protection if the loop can drop below zero.
Related Products
Other Parts Of The Range
TEC Standard Peltier Modules
158 catalogue sizes from 10×10 mm to 80×120 mm, Qmax 1.6 to 480 W.
Learn more
TEA Aluminium Substrate Modules
A 122 W/m·K substrate that raises efficiency 30 to 50 %.
Learn more
TE Accessories
Power supplies, controllers, thermistors and thermal interface materials.
Learn moreRelated Applications And Guides
Where This Product Is Used
How To Select A Peltier Module
Turn a heat load and a delta-T into a shortlist of part numbers.
Learn more
Peltier Module Installation Guide
Mounting force, flatness, thermal interface and sealing.
Learn more
Thermoelectric Module Reliability
Why our modules reach 300,000 hours and what shortens that.
Learn moreFAQ
Frequently Asked Questions About Liquid To Liquid Assemblies
How much cooling can a liquid to liquid assembly provide?
It is configured to the duty. Give us the fluid, the flow rate, the inlet temperature and the target temperature and we will size the module count and exchangers.
Why choose this over a compressor chiller?
At low cooling powers a compressor is oversized and cycles, which makes the fluid temperature swing. A thermoelectric unit modulates smoothly, is silent, is much smaller and carries no refrigerant.
Can it heat the fluid as well?
Yes. Reversing module polarity heats instead of cooling, which suits instruments that must work above and below ambient.
What fluids can be used?
Tell us the fluid and any additives. Compatibility between the fluid, the exchanger material and the seals has to be confirmed for the design life.
Send Us Your Heat Load
Tell us the watts to remove, the temperature to hold and the ambient you have to survive. We will configure the assembly around modules from our own production.
No forms. Messages reach our engineering desk directly. Reply within 24 hours, Monday to Friday, 9:00 to 17:00 Beijing time.