Airflow Geothermal Kit


Airflow Geothermal Kit

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£2,959.06 £2,465.88
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Further Information


  • Brine pump (230 V), includes safety device 
  • Temperature gauges for supply and return
  • Automatic protection against reverse flow
  • Pressure expansion tank - 12 litres, connection ¾”, delivered with wall bracket and stop valve for maintenance
  • Electrical terminal box with 24 V DC relay and operation switch
  • Undersoil tube with screw connections and 20l canister with ethylene glycol
  • Flexible PE-HD undersoil tube - 100 running metres, Ø32 mm, wall thickness 2.9 mm
  • Screw connection set made from high class polymer (PP) to connect the undersoil tube to the hydraulic kit
  • 20l canister with ethylene glycol to ensure antifreeze protection for the system.
  • Glycol has to be homogeneously mixed with water first before filling the pipe-work system. The following mixing
  • Glycol mixing ratio Frost protection until °C - 22% -10°C    - 29% -15°C    - 35% -20°C      -40% -25°C




Airflow Geothermal Kit

Product Part Number

Airflow Geothermal Kit - AFGEOTHERM


The Brine to Air Exchanger enhances the thermal efficiency of your MVHR unit by provided additional preheating to your unit during the winter and also helps to cool the air during the summer.

The Brine to Air Exchanger uses the warmth in the ground to maintain the brine’s temperature of 8 - 12°C. A 1.2 m deep flexible polyethylene under-soil tube pumps brine through a loop.

To increase the heat exchange the tube should be laid directly under the soil in a sand bed. The minimum space between the parallel tubes should be 0.5 m. Alternatively to laying the tube horizontally a vertical bore can be used.

geothermal MVHR

Key Features

  • Connect your MVHR unit for enhanced thermal efficiency
  • Can be automatically controlled by an Adroit unit
  • Brine is kept at a sub-soil temperature of 8 to 12o C
  • Provides additional pre-heating to your MVHR unit during the winter
  • It also provides cooler air in the summer
  • Water temperature gauges monitor the supply and return temperature of the brine
  • Fitted with a G4 filter
  • Wall mounted, 12 litre pressure expansion tank with relief valve included


Brine to Air Energy collector can work either in automatic or manual mode. In automatic mode operation of the circulation pump is controlled by the MVHR unit. The pump circulates the brine when the outside air temperature falls below 5°C or when actual supply air temperature is higher than the set value. System can be switched into the manual mode by using an operation switch. In this mode the circulation pump is always turned on regardless of the outdoor air temperature.


Brine to air heat exchanger is mounted in-line before mvhr unit. It is important that the air flows through the heat exchanger in horizontal direction. To provide optimum performance it is recommended that approx. 1m of straight duct is mounted upstream and downstream of the brine to air heat exchanger. The ducting should be done with Airflex ISO system to avoid creation of the condensation. Alternatively insulated spiral ducting can be used. Pipework and connection between hydraulic kit and brine to air heat exchanger shall be provided on site. The pipe connections of the hydraulic kit are ¾” IG. The quick vent valve must be installed at the highest point of the pipework. It is recommended to install undersoil tube when outdoor air is above 5°C. The area where the undersoil tube is laid should not be built over so it is guaranteed that seeping rainwater can contribute to the thermal regeneration of the soil. The filling of the system is carried out via feed and drain cock located on the hydraulic kit. During this operation take care to avoid air entering the system. After the installation of the undersoil pipework, system should be tested at high pressure for tightness check.

How does a brine Geothermal system work

A network of brine (salty water) filled pipes are buried at a depth of approx 1.5 meters and connect to the air intake of a heat recovery ventilation system via a heat exchanger.

The geothermal ducts use the energy stored in the ground. At a depth of 1 - 2 meters, the ground temperature in the UK varies between +8 and +12 ºC depending on the season and on the soil type. By using the relatively stable temperature at this, the efficiency of the ventilation system is greatly improved

 This provides a source of heating or cooling for a building. As an example, if in the winter months the outside temperature is -5ºc, the ground temperature is +8ºC, the incoming air to the house from the earth ducts could be around +4ºC. Conversely, in the summer where the outside temperature is 28ºc, whilst the ground temperature is +12ºC, the air into the house could be a more comfortable +16ºC.

The benefits Reduce heating costs by pre-warming the air in winter Pleasant cooling effect in summer, reducing the need for air-conditioning Improvement of the air quality in the building through duct and pollen filters

The Benefits over ground to air systems is that no contaminants of mould or bugs can enter the ventilation system and does not require a service pipe or drains to clear outside the property

Our Comprehensive Kit Consists Off

  • Brine to air heat exchanger
  • Hydraulic kit: Brine pump (230V), automatic protection against reverse flow, temperature gauges for supply and return,
  • Pressure expansion tank -12 litres,
  • Thermostat module
  • Terminal box,
  • Operation switch
  • Under soil hose (100 running mtrs) set with screw connections
  • Ethylene glycol (20l)


Technical Specification


Brine to Air Energy Collector is delivered as a kit, which ensures full functionality and optimal performance. Components included in the kit: - Highly efficient brine to air heat exchanger delivered with ceiling / wall mounting plate. Heat exchanger fins are made of aluminium to ensure the best heat transfer to incoming outdoor air. Tubes inside the heat exchanger are made of copper. There is a convertible G4 filter integrated, which prevents the contaminating of the heat exchanger and enables variable air flow direction. The Filter must be always mounted before heat exchanger. The filter should be cleaned 2 to 4 times a year and replaced at least once a year. Heat exchanger should be periodically checked to see if it gets dirty and should be cleaned if necessary. Condensate connection located at the bottom of the heat exchanger casing must be checked before the cooling season

Specification of Brine to air heat exchanger

  • Casing Double skin steel with insulation Heat exchanger 
  • material Aluminium Heat exchanger
  • Pipe connection Copper, 2 x Ø12 mm
  • Duct connection 2 x Ø200 mm
  • Condensate discharge 12 mm
  • Filter G4
  • Weight 16kg

airflow geo brine heat exchanger




BPC have years of experience in delivering equipment around the UK and other Worldwide destinations. Our dedicated dispatch team work hard to ensure the highest standards are met so that your goods arrive on-time and in pristine condition.

Our market knowledge and experience allow us to match our service to meet your requirements swiftly and safely.

Free Delivery

We offer free delivery on any order over £100 to any mainland UK or Ireland address  

Worldwide Delivery

Worldwide delivery is possible on almost all our products at low costs, delivery to countries outside the EU are normally delivered to the nearest customs office, port or terminal for the purchaser to collect and complete custom clearance.

Please contact us to confirm shipping cost and availability.  

End-To-End Support Delivery is available within 48-72 hrs, depending on method of transport, for hundreds of stock items.

Customers receiving a pallet delivery will be emailed on day of dispatch advising of delivery date. Parcel deliveries will be notified via email or SMS directly from DPD.

These checks are part of a unique commitment to building relationships with customers, understanding their specific delivery needs and responding to them positively and promptly.  

We deliver on Service

Key components such as ductwork and fittings plus the most popular selling MVHR units are kept in stock in our UK-based warehouse, which means that you receive the best possible delivery dates.

All goods are expertly packed by a professional team so that your equipment is received in pristine condition ready for installation.

All deliveries co-ordinated to suit your specific requirements and construction programme.

Delivery Partners

We only use the couriers with the highest standard of service that include

  • Fastway
  • DPD
  • Montgomery Transport
  • Liam Connolly Roadfreight Ltd
  • Europa Worldwide


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