Oak Frame Property, Kent

Preliminary items

Upon the customer awarding the contract to Worcester Renewable Energy, prior to commencing the installation a number of detailed design items were undertaken. These were:

Heat Loss Calculations – to confirm the size of air source heat pump specified based upon the actual U-values of the construction details of the building elements, internally heated areas, internal and external design temperatures.

Cooling Calculations – to confirm the size of the air conditioning system specified based upon the U-values of the construction details of the building elements, solar gain, internally cooled areas, internal and external design temperatures.

Wind & Snow Load Calculations – to confirm the roofs were structurally capable of supporting the loads to be imposed upon it by the Photovoltaic (PV) solar panels.

MCS020 Calculation – to confirm the proposed location of the air source heat pump met with permitted development requirements.

Probable Water Demand Calculation – to establish the flow rate required from the incoming cold water main to meet the property water demands.

Distribution Network Operator (DNO) applications – to obtain connection offers to connect the proposed air source heat pump and Photovoltaic (PV) systems to the national grid.

Site survey

Prior to commencing the installation, a site survey was undertaken to go through the proposed works as set out in the formal design guide produced for the project following completion of the preliminary items design work.

The design guide, specific to the project, set out all the information associated  with the installation for reference by all parties involved, resulting in works progressing smoothly and an uncompromised end installation.

First fix pipework

The first stage of the installation was installing all of the first fix pipework throughout the building to transport the hot, cold and heating water from the plant room to its end locations.

Pipework was sized to ensure the design flow rates at the sanitary ware outlets (high flow showers, standing bath taps, wall mounted basin taps) were achieved.

Pressure Test

Upon completion of the first fix pipework it was pressure tested to 1.5 times its working pressure to ensure it was free from leaks prior to the property being dry lined.

Pipework insulation

All fist fix pipework was insulated above and beyond building regulations to ensure minimal heat loss from, and transfer to adjacent pipework.

Completed first fix pipework

The completed first fix pipework is securely held in place with pipe clips and galvanised strap banding.

Soil stack ground floor connection points

The underground soil and waste pipework was brought up through the beam and block ground floor in suitable locations for the bathrooms ready for the soil stacks to be connected to.

Soil stacks

Soil stacks were installed and securely fixed from the ground floor connection points up through the intermediate floors to the rooms and roof spaces above.

Waste pipework

Waste pipework from all the sanitary ware in the bathrooms, kitchen and utility was installed back to the soil stacks with the fall on the pipework was in strict accordance with building regulations to ensure waste water easily drains away without risk of blockage.

Soil stack termination

The soil stack on the furthest run was terminated at roof level via a terminal vent ensuring the soil and waste system is correctly vented to avoid the potential for any siphonage issues.

Thermostatic blending valves

To prevent the risk of scaling and comply with building regulations, easily accessible thermostatic blending valves were fitted to the pipework servicing baths where the bath taps did not contain thermostatic mixer cartridges.

Ground floor insulation

Unlike a traditional ground floor construction where the insulation is laid under the concrete slab, because underfloor heating was being installed a reverse slab construction was adopted.

The insulation was then laid on top of the concreate slab prior to the screed, containing the underfloor heating pipework being laid over it.

The insulation thereby prevents heat from the underfloor heating system travelling downwards into the concrete slab.

Ground floor underfloor heating edge expansion & castellation plates

To allow for expansion of the screed containing the underfloor heating system, edge expansion foam was installed around the perimeter or all rooms.

Castellation plates were installed as opposed to tacking or clipping the pipework directly to the insulation. These ensure accurate and uniform pipe spacing as well as suspending the pipes to allow complete screed coverage around their full diameter. Because a manual screed was being used, the plates also protected the pipes from foot traffic reducing the possibility of damage whilst the screed was being laid.

Ground floor underfloor heating pipework completed

With the castellation plates in-situ, laying of the underfloor pipework circuits progressed systematically and smoothly.

Ground floor underfloor heating pipework tails

Each of the underfloor heating circuits was returned back to the manifold location where they were meticulously cut to the required length and turned through 90° using pre-formed bends to ensuring each pipe was not kinked before connecting them to the manifolds.

Each of the underfloor circuits was labelled so that the actuators could be correctly wired to corresponding room thermostats during the electrical second fix.

Ground floor underfloor heating fill and pressure test

Once all the circuits had been connected to the manifolds, the pipework was flushed, filled and pressure tested above its working pressure to ensure it was free from defects and leaks prior to the screed being laid over it.

First floor perimeter edging

Before the first floor underfloor heating routed gypsum fibrous boards were laid, all the rooms receiving carpet were edged with 100mm wide by 18mm thick plywood.

This allowed the thin plywood overboarding to be securely fixed round the perimeter of the rooms which ensured there is no spring in the ply overboarding. The edging further ensured that no pipework is present around the perimeter of the rooms where carpet grippers were installed which could have resulted in pipes being pieced by carpet fitters.

First floor underfloor heating boards & end returns

Once all the perimeter edging had been completed, the gypsum fibrous boards were laid and securely screwed in place to the floor deck beneath.

End returns were installed along the edge of the underfloor boards to allow the pipework to return upon itself in a uniform manner.

First floor underfloor heating pipework completed

With the overlay boards and end returns in-situ, laying of the underfloor pipework circuits progressed systematically and smoothly.

First floor underfloor heating flow & return pipework to rooms

The flow and return pipework to from the manifold to the rooms was then filled with a sand and cement mix prior ready for the system to be overboarded with a thin layer of plywood.

First floor underfloor heating pipework fill & pressure test

Each of the underfloor heating circuits was returned back to the manifold location where they were meticulously cut to the required length and turned through 90° using pre-formed bends to ensuring each pipe was not kinked before connecting them to the manifolds.

Each of the underfloor circuits was labelled so that the actuators could be correctly wired to corresponding room thermostats during the electrical second fix.

Incoming services

To save valuable floor area in the property itself, all the large mechanical and electrical equipment was located in a plant room within the separate garage building. This required a number of cold water pipes (mains cold, balanced cold, balanced hot, hot return) to be ducted across to the main house where they were neatly risen into the intermediate floor within a utility cupboard.

Plant room setting out

The garage plant room was methodically marked out with where the all pipework was to be installed prior to commencing.

Plant room pipework in progress

The plant room pipework quickly started to take shape as a result of the accurate setting out.

Plant room insulation

All pipework within the garage plant room was insulated with foil back insulation.

Plant room hot water cylinder

The hot water cylinder installed was sized to meet the property hot water demand based on the number and type of hot water outlets and their diversified use.

Plant room equipment installed

With the plant room equipment in place and the distribution system fully installed the final stage of the installation was to commission it.

The heating pipework was and filled with water and glycol to ensure it is protected down to -15°C, checked using a refractometer.

The operating parameters, such as the weather compensation heat curve and hot water temperature were then set within the air source heat pump controller and a commissioning certificate completed with all the commissioning readings and settings recorded.

Plant room labelling

Once the plant room installation was complete, all valves were clearly labelled to allow the customer, or anybody working on the system, to be able to easily and quickly identify them.

Plant room metering

The air source heat pump system, hot water immersion element used only for legionella pasteurisation of the cylinder and the air conditioning system were installed with dedicated electrical supplies, clearly labelled in the property consumer unit. Having dedicated electrical supplies allows any electrical faults to be easily traced to the area of the electrical system containing the fault.

Air conditioning first fix

The refrigeration pipework and air conditioning internal units were installed throughout the roof space so that the only visible component inside the property was the ceiling diffusers.

Air conditioning ceiling diffusers

The air conditioning diffuser grills were colour matched to the RAL colour of the ceilings so that they blended in a far a possible.

Garage roof boarded

Prior to installing the PV panels the garage roofs were boarded to ensure the panels could be securely fixed.

Garage roofs felt and battened

The garage roofs were felt and battened by the roofing contractor ready for the PV panels to be installed.

PV panel optimisers

Due to a slight risk of shading which could potentially reduce the output from the panel arrays, optimisers were installed to each panel.

PV panel installation

Each of the PV panels was installed into position connecting the DC cables to the adjacent panels.

Each connection was encased with an Arcbox to prevent the risk of fire.

PV panel flashings

Flashing kits were installed around the perimeter of the panel arrays so that the roof tiles could be tiled over them keeping the system weathertight as well as it being more aesthetically pleasing than using hooks where the panels above the roof surface.

PV panel flashings

Flashing kits were installed around the perimeter of the panel arrays so that the roof tiles could be tiled over them keeping the system weathertight as well as it being more aesthetically pleasing than using hooks where the panels above the roof surface.

PV panels completed

The completed garage roofs  look aesthetically pleasing with the panels neatly set into the clay tiled finish.

Each of the panels was also cleaned to ensure the system produced the maximum amount of renewable electricity from the outset.

Photovoltaic (PV) inverter, battery storage & Emergency Power Supply (EPS)

A SolaX hybrid inverter to maximise the conversion of the DC electricity generated by the PV panels to AC electricity for use was installed in the plant room. The inverter is Wifi enabled allowing the system to be monitored and managed both locally and remotely via the internet when away from the home through the easy to use application. The application facilitates the management and monitoring of the system allowing the customer to access key system data at anytime, anywhere. For example, being able to visualise and compare actual yields with those estimated is essential in ensuring the system is operating at peak performance.

SolaX battery storage was installed in conjunction with the inverter to maximise the self-consumption from the PV panels.

The batteries can also be force charged with cheap rate electricity from the grid during off-peak times when electricity suppliers offer cheaper tariffs. This cheap rate electricity then being used during the following day to power the home and heat pump system.

Air source heat pump & air conditioning external units

The air source heat pump and air conditioning externa units were located to discreetly to the rear of the garage and plant room.

Completed bathrooms

Due to the accurate first fix, second fix of the bathrooms progressed smoothly resulting in beautifully finished rooms exactly to the customer designs.

Wet room shower trays with tiled wastes

The shower trays specified contain wastes that are tiled so that the wet room floors are not spoilt by easily visible waste traps.

Completed kitchen

Due to the accurate first fix, second fix of the kitchen and utility progressed smoothly resulting in beautifully finished rooms exactly to the customer designs.

Finished interior of property

The beautiful completed interior of the property.

Completed property

The finished property which has all its heating and hot water provided by the new air source heating system and electricity provided by the Photovoltaic (PV) system.