Heat-transfer fluids and heat pipes: Impact on the biosphere

Leaky refrigerants, protected permafrost and 500 Mt of CO2 avoided

What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).

The main biosphere issue is refrigerant leakage: many fluorinated refrigerants are powerful greenhouse gases, and newer ones raise concerns as persistent PFAS chemicals. Heat pipes have one notable ecological benefit, protecting permafrost under the Trans-Alaska pipeline.

Example refrigerant footprint 2 kg at GWP 3,922 = 7.8 tonnes CO2e¹² Emissions avoided by EU F-gas rules about 500 million tonnes CO2e by 2050¹² Pipeline supports with permafrost protection 78,000 vertical support members, some with paired heat pipes⁹

Effects over time

Life affected	Short term	Medium term	Long term
Humans¹²¹⁴	Little evidence of effect.	Leaked refrigerants warm the climate: a 2 kg charge of a refrigerant with GWP 3,922 equals 7.8 tonnes of CO2.	Some newer fluorinated refrigerants fall under the EU PFAS restriction process, which is assessing their persistence, hazards and emissions.
Animals¹⁴	Little evidence of effect.	Little evidence of effect.	Little evidence of effect.
Plants¹⁴	Little evidence of effect.	Little evidence of effect.	Little evidence of effect.
Fungi and soil life⁹	Little evidence of effect.	Pipeline thermosiphons keep permafrost soil frozen beneath supports.	Little evidence of effect.
Ecosystems⁹¹²	Little evidence of effect.	Protecting permafrost avoids thaw damage along 420 miles of elevated pipeline.	Full EU F-gas implementation is estimated to avoid about 500 million tonnes of CO2e by 2050.

How the effects are reduced

Leak-tight equipment, recovery of refrigerant at end of life and a switch to low-GWP or natural refrigerants cut the climate impact. Thermal oils and salts are kept in closed loops. The EU PFAS process may require monitoring and emissions reporting for any refrigerant uses it exempts.

Sources

Pipeline designs protect permafrost PBS American Experience, 2006
A Concise Guide to the EU F-Gas Regulation Environmental Investigation Agency, 2026
ECHA's update on the REACH restriction on PFAS (100th EFSA Advisory Forum) European Chemicals Agency, 2026