Manor House, Kent

A beautiful and sustainable oak frame manor house installs an air source heating and Photovoltaic (PV) system

Case study summary

The customers of a beautiful sustainable oak frame manor house entrusted the help and services of Worcester Renewable Energy to design and install complimentary renewable energy systems, as well as undertaking all the general plumbing and heating work including the installation of all bathrooms.

The systems generate localised renewable heat and electricity reducing the reliance of the property on fossil fuels, thus reducing its energy costs, CO2 emissions and its impact on the environment.

After completing detailed heat loss calculations, a NIBE 16kW air source heat pump, complete with NIBE 500 litre hot water cylinder and NIBE 220 litre buffer tank was specified to provide renewable heating and hot water to the property.

To distribute the renewable heat throughout the property, a Polypipe solid floor screeded underfloor heating system was installed to the ground floor with the pipes laid closely together at 100mm centres in a spiral layout to achieve the maximum heat output at the low weather compensated design flow temperatures of the air source system, maximalising the efficiency of the heat pump and minimising running costs.

A Polypipe Overlay underfloor heating system was installed on the first floor, laid on top of the intermediate floor. The overlay system offering much higher heat outputs at the low weather compensated design flow temperatures than traditional aluminium plated systems that are installed between floor joints underneath the insulating chipboard decking, again maximising the efficiency of the heat pump and minimising running costs.

All the underfloor heating controls are Wifi enabled allowing the customer to control the system both locally and via the internet using smart phones and tablets.

A roof-integrated Viridian Solar 5.67kW PV system was installed on the South facing roof garage roof to provide renewable electricity to both the air source heat pump system and general electrical use of the property. 11.6kWh of battery storage was installed with the system to maximise the amount of renewable electricity self-consumed as well as allowing force charging of the batteries with off-peak electricity for use during peak times.

Customer testimonial

The Case study describes in detail the technical installation process and associated equipment very well. We are extremely pleased with the end installation and how everything interacts  together so well.

So, as owners of our house in Kent, we thought it would be useful to describe our first class interaction with the various team players at Worcester Renewable Energy.

Border Oak, our custom house builder, arranged for two proposals to be sent to us. The proposal from WRE contained a full and comprehensive description of what they proposed to supply, with various additional options for us to consider.  At first the level of detail was a bit intimidating for us as renewable energy novices, but after a few explanatory phone calls and emails with Darren Stockall we realised we were dealing with a very professional company and team. This gave us the confidence to accept their proposal to carry out the work described and to opt for extras, such as the PV system and storage batteries.

When the installation team arrived on  site we immediately warmed to them. They were polite,  helpful, friendly and clearly knowledgeable. During the installation, most of which was a mystery to us, we had many questions which they were very happy to provide clear, understandable answers.

We had sourced the sanitary ware for the bathroom and shower rooms from a reputable local supplier ourselves and, inevitably,  during the installation a few issues arose. These did not concern the team who worked around these with no problems. Tom, the installation manger for our project, took it upon himself to liaise directly with our suppliers so he could get items changed as necessary, without putting us to the trouble of doing so. He even insisted that one shower door was imperfect (even though we would have accepted this) and succeeded in persuading the supplier to replace this – Free of charge!!.

At the end of the installation as part of the handover Tom walked us through the various system components, clearly explaining their functions,  and showed us how to use the apps. Again we had lots of questions which Tom patiently answered at the end of his long, hard day.

We also had dealings with Graham, the project manager for our installation, and Natalie in the WRE office who dealt with out Boiler Upgrade Scheme Grant Application amongst other things. We were led through this process very well by Graham who asked us to provide various evidence and he succeeded in obtaining the full grant which Natalie promptly arranged to pay us. A very welcome success! This was followed up with the provision of a detailed handover pack.

In summary, we would recommend WRE to potential customers without question or hesitation. There were no surprises on costs. We now have a fantastic, well installed and efficient system in place which should meet our needs for many years to come.

Thank you!

Mr & Mrs Fleury, owners.

Preliminary items

Upon the customer awarding the contract to WRE, 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 various building elements, internally heated areas and internal design temperatures.

Wind & Snow Load Calculations – to confirm the roof was structurally capable of supporting the loads to be imposed upon it by the PV system.

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 PV system to the national grid.

Site survey

A formal design guide was produced for the project and a site survey arranged prior to any installation work taking place. During the site survey the content of the design guide was checked and discussed with the customer and construction project manager to ensure that it met the needs and expectations of all invested parties. This resulted 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 such as high flow showers, standing bath taps and wall mounted basin taps.

Pipework insulation

All first fix pipework was then insulated exceeding building regulations to ensure minimal heat loss from, and transfer to adjacent pipework.

Identification tape

Where first fix plastic pipework runs vertically in walls, aluminium identification tape was taped over the pipework so that its location could be identified after concealment, to avoid them being pierced by fixings when fitting items such as kitchen units, shelves and pictures etc.

Soil & waste pipework

Soil and waste pipework from all the sanitary ware in the bathrooms, kitchen and utility was then installed ensuring the fall on the pipework was in accordance with building regulations to allow waste water to easily drain away without risk of blockage.

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 concrete slab prior to the screed being laid over it which contains the underfloor heating system. The insulation thereby prevents heat from the underfloor heating system travelling downwards into the concrete slab.

Moisture migration barrier

To prevent the screed covering the underfloor heating system reacting with the insulation sheet, a polythene moisture migration barrier was installed.

Ground floor underfloor heating edge expansion

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

Ground floor underfloor heating castellation plates

Rather than tacking or clipping the pipework directly to the insulation, castellation plates were installed. These ensured 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

With the castellation plates in-situ, laying of the underfloor pipework circuits quickly progressed.

Completed ground floor underfloor heating pipework

Once all of the underfloor heating circuits were installed the accurate and uniform pipe spacing becomes evident.

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 ensure uniform and unkinked pipe, before connecting them to the manifolds.

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 being screeded over.

Ground floor underfloor heating completed manifolds

Each of the underfloor circuits was methodically and clearly labelled so that the actuators could be correctly wired to corresponding room thermostats during the electrical second fix, and to allow for quick and easy identification in future years.

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 result have resulted in pipes being pieced by carpet fitters.

First floor underfloor heating boards

Once all the rooms requiring edging had been completed, the gypsum fibrous boards were laid and securely screwed in place to the floor decking beneath.  The installation of the pipework then took place into the pre-routed groves within the boards.

First floor underfloor heating end returns

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

First floor underfloor heating boards and end returns

The underfloor boards and end returns were completed ready to receive the underfloor heating pipework.

First floor underfloor heating pipework

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

Completed first floor underfloor heating pipework

Once all the underfloor heating circuits were installed the accurate and uniform pipe spacing was evident.

Plant room setting out

The plant room contains much of the plumbing and electrical equipment, all in one place. In consultation with the architect at the design stage WRE advised on the size of space required and the amount of equipment that was to be installed. The plant room provides a single, accessible location for any future servicing and maintenance and provides the customer with a central plant location rather than a property that contains a number of services located throughout.

At this stage the plant room become the main focal point of our installation, diligently marked out with where the pipework and equipment was be installed

Plant room in progress

The plant room started to take shape, ‘joining the dots’.

Plant room nearing completion

With the plant room complete and the distribution system fully installed, the final stage of the installation was to commission it. The heating pipework was filled with water and glycol to ensure it is protected down to -15°C and 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.

Air source heat pump external unit

The air source heat pump was installed in a discrete lcoation to the rear of the garage and plant room.

Roof felt and battened

Prior to installing the PV panels the garage roof was felt and battened.

PV panels

Each of the PV panels were installed into position connecting each of 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 array so that the roof tiles could be tiled over them keeping the system weathertight as well as it being aesthetically pleasing.

PV panel clean

Each of the panels were cleaned to ensure they produced the maximum amount of renewable electricity from the outset.

Complete PV array

The completed PV array was then ready for tiling around by the roofing contractor.

Finished roof containing the integrated PV system

The completed garage roof with the PV system neatly and aesthetically set into the clay tiled finish.

Completed second fix sanitary ware

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

Completed property

The finished project is an impressive property, which has all of its heating and hot water provided by the new air source heating system and a large proportion of its electricity requirements covered by the new PV and battery storage system. We feel that our customer can now enjoy a beautifully presented property that provides comfort, running cost savings, boasts green credentials and is something they can call home. Worcester Renewable Energy were proud to be a part of this project and others on the same site.