# Heat-transfer fluids and heat pipes

Fluids and devices that move heat: thermal oils, molten salts, refrigerants, heat pipes and trucked heat stores.

Source page: https://www.materialinsights.org/energy/e_heat_carriers/

Transport · Heat, motion and embodied energy · No. 65

- Transport
- Form: Heat
 Transport · Heat, motion and embodied energy · Foundation · Energy

In 1833 a ship sailed 180 tonnes of ice from Boston to Calcutta, and over half of it survived the four-month voyage.

Chart: Illustration: Heat-transfer fluids and heat pipes

##### Where it comes from

Chart: Map of where it comes from

Heat moves by conduction, convection and radiation, so engineers match the carrier to the temperature: thermal oil up to 400 C, molten salt from about 290 to 565 C.

##### Three things to know

1. A heat pipe conducts heat at an effective 10,000 to 100,000 W per metre per C, far beyond copper's 390, with no pump at all.
2. A leaked 2 kg refrigerant charge with a GWP of 3,922 warms the climate as much as 7.8 tonnes of CO2.
3. Passive ammonia heat pipes keep the permafrost frozen beneath 420 miles of elevated oil pipeline.

##### The journey

1. 1 **Heat source**Solar field, furnace, chip or waste heat
2. 2 **Carrier**Oil, molten salt, refrigerant or heat pipe
3. 3 **Transport**Pumped loop, wick or trucked container
4. 4 **Storage**Insulated tanks hold heat for hours
5. 5 **Release**Heat exchanger hands heat to its user

##### Go deeper pick a tab to open it in full

## Other sections

- [Overview](https://www.materialinsights.org/energy/e_heat_carriers/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_heat_carriers/correlation/index.md)
- [How it works](https://www.materialinsights.org/energy/e_heat_carriers/explain/index.md)
- [Efficiency and losses](https://www.materialinsights.org/energy/e_heat_carriers/efficiency/index.md)
- [Technology advances](https://www.materialinsights.org/energy/e_heat_carriers/advances/index.md)
- [Value chain](https://www.materialinsights.org/energy/e_heat_carriers/valuechain/index.md)
- [Geopolitics and regulation](https://www.materialinsights.org/energy/e_heat_carriers/geopolitics/index.md)
- [Unit economics](https://www.materialinsights.org/energy/e_heat_carriers/economics/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_heat_carriers/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_heat_carriers/links/index.md)