Open Loop Water Source Heat Pump Systems

Open Loop Water Source Heat Pump Systems –

In the drive to reduce carbon emissions the world has seen a proliferation of renewable technologies.  Here at Rotorflush Filters Ltd we have seen an increase in enquiries for the use of our products with heat pumps – particularly for use with open loop water source heat pump systems.

Kensa-pump-73003 could be used as open loop water source heat pump

Kensa ‘Shoebox’ Heat Pump


What is an Open Loop Water Source Heat Pump System?

Diagram of open loop water source heat pumpHeat pump systems work by recovering heat (solar energy) stored naturally in the air, ground or water and using this recovered heat as a source of energy to heat homes and businesses.

In open loop water source heat pump system uses open water, such as a lake, river, pond or the sea as its heat source. The water passes through heat pumps to transfer its heat before being returned to the water source.

Filter pump to protect open loop water source heat pump

Heat pump installers and manufacturers are recognising the benefits of Rotorflush submersible pumps for supplying their equipment.

Our low head energy efficient pumps with built-in self-cleaning suction intakes allow river and other open water to be filtered pumped through plate heat exchanges.

The self-cleaning filters prevent weed and other debris from entering the system and the self-cleaning rotors keep the filter clear.

They offer a low maintenance solution to supplying open loop water source heat pumps where the water quality may be variable.


John Barker-Brown, special projects manager at British heat pump manufacturer Kensa Heat Pumps says:

“Using water as your energy source has a number of advantages when compared to air or ground source:

  • The heat transfer rate from water is far higher than that in the ground or air. • The flow/circulation of the water source provides constant energy replacement.
  • The use of a water source removes the need of digging large trenches, often reducing the cost of installation compared to a ground source.
  • The return temperature to the heat pump is usually higher than either the ground or winter average air, increasing the CoP (coefficient of performance) of the heat pump.”


Why are Open Loop Systems becoming more Popular?smokey2

The UK and other countries are seeking to reduce their output of greenhouse gases by the increased use of renewable energy and low energy systems

In the UK the Renewable Heat Incentive (the RHI) provides an incentive for installing heat pump systems. RHI is a payment system for the generation of heat from renewable energy sources introduced in the United Kingdom on 28 November 2011.  It applies to industrial and domestic installations.

Agreeable riverside premises that could use an open loop water source heat pumpWater has a greater capacity to retain heat than air, and it is better at transferring heat in plate heat exchangers. Air systems are at their least efficient on the coldest days when they are most needed, whereas river and lake water is a more efficient store for heat, retaining energy from the sun that has built up in the preceding months.

The Dept for Energy and Climate Change (DECC) recognises that there is huge scope for open loop water source heat pump systems within the UK and has published a map identifying the 40 urban areas that can immediately benefit from the adoption of these systems.


The use of Rotorflush filter pumps has increased the feasibility of low maintenance open loop water source heat pump installations.


What to Consider when Planning an Open Loop Water Source Heat Pump SystemAnother agreeable river side premises that could benefit from an open loop water source heat pump

Installation – Open loop systems can be cheaper to install than digging trenches if a readily available source of water is used.

Efficiency – Open loop systems can have a higher efficiency than ground source due to the higher water source temperature.

Licences – When extracting or drilling boreholes for extraction the Environmental Agency needs to be consulted for the appropriate licences. Have a look HERE for how licensing may apply to you.

Filtration – With open loop water source heat pump systems there is a requirement for filtration and additional maintenance issues which must be addressed. HERE is where Rotorflush Filters can help.

kensa-logoMuch more information about heat pumps and heat pump installations can be found at Kensa Heat Pumps who have provided much of the information on this page.


For more information about how Rotorflush Submersible Pumps with their unique and patented self-cleaning intake filters can protect your open loop water source heat pump installation contact the Rotorflush team:

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