Frequently Asked Questions (FAQs) about Kensa Shared Ground Loop Arrays (SGLAs)

Got a question about shared ground loop arrays? Read through some of the most common questions below. If you cannot find an answer to your question please contact us on 0845 680 4328 or send us your project details for a bespoke quote.

What is a Ground Source Heat Pump (GSHP)?

A ground source heat pump is an electro-hydraulic system that gathers low temperature heat (0-14C) from the sun and rain stored in the ground, and multiplies this collected heat through exchange and compression into usable hot water for both room heating and hot water.

Visit KensaHeatPumps.com for more information on 'what is a heat pump'.

What is a shared ground loop GSHP system?

A Shared Ground Loop Array is a low temperature heat network consisting of multiple buildings, each with their own ground source heat pump (GSHP), all connected to one common, shared ground loop. In its simplest form it could consist of two houses each with their own GSHP connected to one common borehole.

Is there any limit to the number of properties that can be connected on a shared ground loop GSHP system?

No. Shared Ground Loop Array GSHP systems are infinitely scalable for large developments. However, in practice, it is likely that on a large project a number of shared ground loop systems would be installed to suit the layout of the site. See Kensa SGLA project examples in our Knowledge Hub.

Is there any requirement for metering and billing on a shared ground loop system?

No. The individual heat pumps are connected to the electricity supply of each individual house. Consequently, each householder pays for their heating via their own electricity bill and has freedom of choice over which supplier and which tariff to use.

What are the main advantages of a shared ground loop system over a traditional central plant system?

No heat loss in distribution pipework. No overheating in risers & corridors. No need for metering & billing. Freedom to switch electricity suppliers. No central plant space required. If a heat pump does fail, only one household is without heating.

Shared Ground Loop ArraysTraditional Heat Networks
+ Ambient loop - no heat losses- Heat loss through network
+ No overheating (Read more)- Overheating in risers & corridors
+ Independent billing- Requires split-billing
+ Independent heat - freedom to switch suppliers- Single heat energy provider
+ No plant room - individual heat pump per dwelling- Large & unsightly central plant
+ Lowest bills- ESCO purchases energy
+ No servicing & minimal maintenance- Highly specialised servicing
+ Robust and reliable- Back up system required
+ Carbon compliant (Read more)- Complex funding claims
+ No emissions (Read more)
+ Free passive cooling (Read more)
+ Integration with smart controls
+ Multiple heat source options
+ Integration with waste heat
+ Inter seasonal heat storage
+ Flexible and scalable
+ Planning exempt

What type of ground loop do you need to install?

Typically, it is closed loop boreholes up to 200m deep. Where space allows it is possible to use slinkies. Other options include open loop systems (using e.g. an underground aquifer or mine water) or surface water systems (pipes submerged in water).

Visit KensaHeatPumps.com for more information about heat sources and ground arrays suited to shared ground loop array systems.

What type of heating controls do you supply with your heat pumps?

Kensa deliberately supply our heat pumps without heating controls & make them compatible with mainstream heating controls familiar to anyone who has used a gas/oil boiler. This also allows installers freedom to use simple or sophisticated controls depending on property/customer needs.

What is the typical life expectancy of a GSHP system?

The GSHP itself is very reliable and is expected to last for between 20 to 25 years. The ground array should last for at least 100 years.

What annual maintenance requirements are there?

There is no requirement for an annual safety inspection or service of the GSHP itself. However, it is usually good practice to carry out periodic checks on the internal central heating system itself as would be recommended with any heating system.

How do running costs compare with other heating systems?

A GSHP system has the lowest running costs of any heating system, even when compared to mains gas boilers. The cost of one unit of heat produced by a GSHP is usually around 4 to 5 p/kWh on a standard flat rate tariff.

How do carbon emissions compare with other fuel sources?

GSHPs have the lowest carbon emissions of any heating system. With the new carbon factors proposed in SAP 10, a Ground Source Heat Pump will produce less than 1/3 of the carbon of a gas boiler or direct electric system, with bigger savings against both oil and LPG.

For more information on how to Reduce Compliance Costs visit our page here.

Are there any emerging opportunities to make shared ground loop systems even more attractive?

Time-of-use tariffs will lower energy bills further, especially if combined with thermal storage or smart controls. PV-T systems will increase ground array temperature and increase the efficiency of the PV system. The ambient temperature ground array can also be used to provide passive cooling.

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