Ground Loop Design

Heat Sources Horizontal ground loops  Collector pipework laid horizontally  Requires large land area  Cost effective Slinkies  Pre coiled pipework laid in trenches  Requires large land area, but less digging  Cost effective Vertical boreholes  Closed loop pipework inserted into vertical hole  Typically m deep  Most common in commercial buildings  Space efficient Surface water (closed loop) o Ideal solution where surface water (eg lake) is available o Extremely efficient and cost effective Open loop  Extracts ground water from an underground aquifer  Efficient  Costly Horizontal ground loops  Collector pipework laid horizontally  Requires large land area  Cost effective Slinkies  Pre coiled pipework laid in trenches  Requires large land area, but less digging  Cost effective Vertical boreholes  Closed loop pipework inserted into vertical hole  Typically m deep  Most common in commercial buildings  Space efficient Surface water (closed loop) o Ideal solution where surface water (eg lake) is available o Extremely efficient and cost effective Open loop  Extracts ground water from an underground aquifer  Efficient  Costly o Ground provides a highly efficient source of heat o Unaffected by air temperature o Recharged by solar energy and rainfall o Ground type (thermal conductivity) needs to be factored into sizing calculations o Important not to over extract – sizing important

Ground Loop Design Table 3 of MIS3005 can be used to help design the ground array in conjunction with MCS022 ground heat exchanger look up tables.

3 Bed Semi detached. From room by room heat losses:- Space Peak Heat Load = kW (6kW heat pump) Annual Energy load = kWh/y DHW load = 3438 kW/y Heating System Radiators with a flow temperature of 50C (3 stars)

Kensa Room by room heat loss calculator 6 kW heat Pump at a flow temp of 50C

Look up extraction tables

Kensa Room by room heat loss calculator 6 kW heat Pump at a flow temp of 50C Wet Clay Southwest From MCS 022

3.4 From Heat Emitter Guide

Property 2 Bed Detached Property Peak Heat Load 3.5kW Annual Energy Load 6580kWh DHW annual load = 2578kWh Underfloor at a flow temperature of 40C (5 stars) SPF 4.1

Kensa Room by room heat loss calculator 4kW heat Pump at a flow temp of 40C Wet Clay Southwest From MCS 022

4.1 From Heat Emitter Guide

 Maximum Power Extracted from the ground:- [ Box 2] x 1000 x (1- ( 1/[ Box 7])) =5.1 x 1000 x (1-(1/4.1)) = 5.1 x 1000 x (0.756) = 3856 W  Maximum Power Extracted from the ground:- [ Box 2] x 1000 x (1- ( 1/[ Box 7])) =5.1 x 1000 x (1-(1/4.1)) = 5.1 x 1000 x (0.756) = 3856 W

4.1 From Heat Emitter Guide

Slinkies Myths:  You need less land area – FALSE  You need less pipe – FALSE  They are less efficient – FALSE  They are more likely to freeze the ground than straight pipe – FALSE Facts:  You need the same land area as a straight pipe collector  There require only a fifth of the digging of a straight pipe collector  Quicker, easier and more cost- effective to install Myths:  You need less land area – FALSE  You need less pipe – FALSE  They are less efficient – FALSE  They are more likely to freeze the ground than straight pipe – FALSE Facts:  You need the same land area as a straight pipe collector  There require only a fifth of the digging of a straight pipe collector  Quicker, easier and more cost- effective to install

Slinkies Horizontal Slinky Trenches Horizontally installed slinkies should be placed in a 1.2m wide by 1.2m deep trench. Vertical Slinky Trenches Vertically installed slinkies should be placed in a mm wide by 2m deep trench. Separation Distances Each trench should be separated by a minimum of 5m between centres Energy Absorption For every 10m of slinky 1kW of energy can be absorbed from the ground. Trench Layout Trenches do not have to be straight, they can twist and turn as long as the 5m separation distance is maintained. Crossing Services Insulate about 1m either side of crossing point

Unrolling a slinky

Manifolds Above ground manifolds Compression Joints – Asymmetrical olives Subterranean manifolds Electrofusion joints mm EF joints 63mm to the heat pump Kensa Supply An optional expansion vessel can be fitted to the slinky pipework.

Pressure testing the slinkies  Pressure test with water (generally safer)  Remove all the air  Pressure Test to EN805 Section (See manual)  Pressure test with water (generally safer)  Remove all the air  Pressure Test to EN805 Section (See manual)

Purging the Slinkies

Antifreeze samples  2 independent antifreeze samples are required by MCS.  Taken from the schrader values an hour apart. Tested using a refractometer and samples returned to Kensa.  Beware some refractometers measure concentration some measure freezing temperature  20% concentration or -10C protection  2 independent antifreeze samples are required by MCS.  Taken from the schrader values an hour apart. Tested using a refractometer and samples returned to Kensa.  Beware some refractometers measure concentration some measure freezing temperature  20% concentration or -10C protection

Installation of the heat pump

Installation of the heat pump Flow to heating system from heat pump 28 mm OD Return from heating system to heat pump. Connected via ‘Y’ connector 28mm OD Speedfit connection termination. Supply to ground 28 mm OD. Connected via ‘F’ connector with a single 50mm Plasson connection termination. Return from ground 28 mm OD. Connected via ‘L’ connector with a single 50mm Plasson connection termination. ‘Y’ Connector ‘F’ Connector ‘L’ Connector

Meter Ready Installations Pipe Diameter (mm) Total length of straight pipework required in return pipe (mm) Total length of straight pipework required in the flow pipe (mm)

Electrical Connections

Simple diagnostics and fault finding.

B readings and settings B01 – Heating Distribution Temperature B02 – Temperature of water returning from the ground arrays B03 – Temperature of water going out to ground arrays B04 – Refrigerant pressure

Fault Codes

Fault Codes