Oaklands London

Oaklands London

Ground source heat pump, rain water harvesting, solar thermal, and underfloor heating

  • 7kWp solar PV on roof
  • 20m² solar thermal array
  • borehole type ground sourced heat pump
  • underfloor heat distribution system using IVT Prineto system
  • 10,000L rainwater harvesting underground system

September 2015

Ground Source Heat Pump

For heating, hot water generation and pool heating

System Design, Supply, Installation and Commissioning:

  • Stiebel Eltron WPF27 Ground Source Heat Pump (GSHP)
  • Stainless Steel heat exchanger for open loop boreholes
  • Submersible Pump and connecting pipework
  • Technische Alternative (TA) control system for single point control of the GSHP, UFH and Thermal Store Cylinder
  • Control elements to connect heat pump to the TiSUN thermal store cylinder, heat sources, underfloor heating and hot and cold distribution systems, to include; circulation pumps, motorised valves, sensors, control cables, flow meters
  • Control System integration to suit heating installation
  • All required hydraulic connections within the plant room to connect to the heating and hot water distribution systems
  • All safety and control elements required for heat pump operation
  • Heat meter as required for RHI payments
  • 2 year parts and labour warranty
  • Handover pack and user guide inc. MCS Certificate and Grid Connection Notification

Design Details

The Ground Source Heat Pump system has been sized based on the supplied information (property size, heat loss based on construction details). The heat pump will supply all the heating for the building and swimming pool as well as the hot water requirements for the property with a supplementary electric immersion heater providing back up to raise the temperature of the hot water as required. The control of the system will be via an external controller; this will allow the heat pump to control the charging of the thermal store cylinder. The control of the heating circuits will be via the heating distribution controls in conjunction with the new controller.

The heat pump will provide hot water to be circulated through the heating system as well as producing the DHW generation. The installed cylinder is a thermal store cylinder. The DHW production will be via a hygienic stainless steel coil that will produce hot water on demand. This will allow the heat pump to provide the majority of the DHW for the refrigeration cycle.

The heat pump will be installed within the plant room alongside the thermal store cylinder. The heat pump will be connected to the boreholes via pipes buried in the garden. The TA control system is a fully programmable control system. Sasie will provide the programme to control the system according to the building’s requirements. The control system will control:-

  • Operation of the heat pump
  • The underfloor heating – each room has been allocated as a separate zone with the main living area split into several zones
  • Switching of the supplementary heating, proposed as an immersion heater within the thermal store cylinder
  • Charging of the thermal store
  • Control of the secondary Domestic Hot Water Circulation
  • Control and Monitoring for all the automatic valves and pumps for the heating and hot water system
Estimated Energy Yield

The calculated energy requirement for the heating and hot water as estimated from the supplied construction details is 39,642.9kWh/annum. Based on this figure the heat pump would be able to cover 100% of the heating load down to -3°C. At temperatures below this the shortfall in output would be met using an electrical immersion heater within the thermal store cylinder.

Photovoltaic System

For electricity generation

System Design, Supply, Installation and Commissioning:-

  • 7kWp Array formed from 28 Renesola 250W photovoltaic modules
  • 1 x 7kW Inverters
  • On roof mounting kit to fix panels to the proposed elevated frame
  • DC electrical isolation, junction boxes, cable and connections
  • AC electrical isolation points, cabling and connections to main distribution board
  • Ofgem accredited 3-Phase kWh Meter
  • Personal display
  • 2 year parts and labour warranty
  • Handover pack and user guide inc. MCS Certificate and Grid Connection Notification

Solar Thermal

For hot water and heating (central heating and pool)

System design, supply, installation and commissioning of:-

  • 20m² (21.72m² actual) TiSUN FA Large collector system; consisting of two FA2/6 collectors
  • Connection to the proposed thermal store cylinder within the plant room
  • On roof mounting kit to fix panels to the proposed elevated frame
  • Solar Thermal control and safety equipment
  • All Hydraulic and Electrical Connections between the solar panel and heating and hot water systems
  • 2 year parts and labour warranty
  • Handover pack and user guide
Design Details

The solar thermal system has been based on the requirement to provide a significant input to the heating, pool and hot water systems. The amount of energy generated from a solar thermal system depends on the amount of water used in the building; energy can only be provided if there is the facility to store it within the hot water cylinder. Once the cylinder is full of hot water no more energy can be stored until that heat is drawn off. In order to accurately size the system the daily usage figures and occupancy would need to be confirmed. The Solar Thermal system will be configured to be the lead energy supply to the hot water system. Any additional hot water heating would be provided via the heat pump this will allow maximum input from the solar thermal system. The energy produced by the solar thermal system will be used, firstly, to provide domestic hot water. Once the hot water system has been satisfied the energy will be diverted to the heating system and then to the pool heating.

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