Ground Source

Thermal Fluid for Ground Source Heat Pumps

Kilfrost GEO


The only high efficiency, NON-TOXIC alternative to MEG for closed loop ground and water source heat pumps


Specifically engineered to improve the performance of closed loop ground and water heat pump collectors. Systems using our new GEO product will benefit from lower pressure drops, reduced pumping costs and higher overall efficiency.

When replacing more viscous fluids such as MPG (propylene glycol) or glycerine (refined vegetable extracts) based heat transfer fluids in existing systems with GEO, your customers will benefit from an immediate increase in pumping and heat transfer efficiency, leading to long term energy savings.


  • Outperforms MEG, MPG & Ethanol based heat transfer fluids
  • Leads to lower system pressure drops
  • Lower pumping costs
  • Higher Heat Transfer Efficiency than MEG, Ethanol or MPG
  • Protects against corrosion and scaling
  • Classified as non-hazardous according to CLP/REACH
  • Superior environmental profile
  • Free from nitrates, nitrites, borates, heavy metals and phosphates
  • Created to Improve MIS 3005 Compliant Collector Design



Viscosity Comparison

Kilfrost GEO has been engineered to reduce pressure drops, reduce pumping costs and increase the hydraulic efficiency of closed loop ground and water source heat pumps.

Heat Transfer Efficiency

Product Data

User Guidelines

As per BSRIA guide BG29/2012 and Building Regs PART L all pipework should be cleaned and sanitised to remove all physical debris and biological growth prior to the installation of a thermal fluid.

Kilfrost GEO is also available pre-diluted with de-ionised water to the required level of freeze protection.


We stock a Thermal Fluid Test Kit which is used to monitor the health of Kilfrost GEO as part of a routine maintenance schedule.

In addition, we (via Kilfrost) offer a number of free comprehensive fluid health checks to our customers


The dilution rate depends on the freeze point required by the system

  • Product concentrate should not be diluted below 25% v/v
  • Product dilutions >30% v/v will give optimal corrosion and scale protection
  • Kilfrost GEO should not be added to systems that already contain heat transfer fluid

Supplied in 20 litre tubs or 1000L IBCs.

Demonstration Video

Sentinel R500C


Exceptional thermal transfer and protection for Ground Source Heat Pump Systems.

Sentinel R500 is a blue glycol based liquid. It’s specifically designed for use as a highly efficient heat transfer fluid providing frost protection in Ground Source Heat Pump equipment and Ground Loop circuits. Offering superior stability, frost protection, exceptional thermal transfer, protection against corrosion and deposits, and resistance to degradation so providing extended fluid life. It also contains an effective biocide that will help to control the growth of bacteria in a sanitised system should it become contaminated after commissioning.

The properties of Sentinel R500C help reduce the costs of system operation. A FrostCheck Test Kit is available for installation validation checks.

  • Resistant to degradation
  • Biodegradable
  • Compatible with Sentinel R700
  • Buffered pH
  • Contains corrosion inhibitors for
    superior protection of system metals
  • Provides effective frost protection
  • Contains a biocide to prevent fouling
  • Non-toxic
  • Supplied as concentrate in 20 litre tubs

For Solar Propylene Glycol products please click here.