A heat pipe heat exchanger uses sealed tubes filled with a working fluid to move heat from one air stream to another. It has no moving parts, requires no external power, and keeps the two streams physically separated.
Working Principle
Each heat pipe is a sealed tube with an internal wick structure. At the hot end, the working fluid evaporates and absorbs heat. The vapor travels to the cold end, condenses, and releases heat. Capillary action in the wick returns the liquid to the hot end, repeating the cycle continuously.
Common Working Fluids
- Water (for moderate temperatures, ~30–250 °C)
- Ethanol and methanol (for low-temperature applications)
- Refrigerants such as R134a or R410a (for HVAC ranges)
- Specialty fluids for high-temperature exhaust
Advantages
- No moving parts, so maintenance is minimal
- No cross-contamination between air streams
- Self-regulating: heat transfer increases with temperature difference
- Can be arranged in U-shape, L-shape, or straight banks
Best Applications
- Mine and tunnel ventilation
- Telecom shelters and battery rooms
- Transformer and electrical cabinet cooling
- Waste heat recovery from low-grade exhaust
- Environments with explosive or contaminated gases
Selection Notes
Heat pipes are best when the two air streams are separated by distance or when complete isolation is required. They are not usually the first choice for very high moisture recovery or very large airflow volumes.
Frequently Asked Questions
Do heat pipes need electricity?
No. The cycle is driven entirely by temperature difference and capillary action.
Can heat pipes freeze?
If water is the working fluid and ambient temperature drops below freezing, anti-freeze fluids or refrigerants should be selected.
Frequently Asked Questions
Do heat pipes need electricity?
No. The cycle is driven entirely by temperature difference and capillary action.
Can heat pipes freeze?
If water is the working fluid and ambient temperature drops below freezing, anti-freeze fluids or refrigerants should be selected.
Specify the right heat exchanger
Our engineers size the core to your airflow, temperature and pressure-drop budget, and select plate, rotary or heat-pipe recovery by application. Read the heat exchanger guide or contact us for a specification.
Related products
Plate, wheel or pipe recovery for HVAC and ventilation.
Stationary, high-surface-area cores for air and liquid.
High-effectiveness energy recovery for large airflows.
Passive, fully separated streams for clean applications.