How to connect a ground source heat pump

Posted by & filed under Evo, Installer.

Kensa Evo Heat Pump

Kensa went on site with long-standing Partner Installer, Edward Savage of EPS Plumbing, Heating & Green Energy, to demonstrate the key points of an installation of a Kensa Evo ground source heat pump in a complete barn renovation in West Cornwall.  Ed has undertaken all of the plumbing and heating throughout the build in addition to the installation of the Evo heat pump.

Ground side

The Evo unit is located in a plant room adjacent to living areas; this is possible due to the latest advances in acoustic insulation and vibration mitigation minimising the Evo’s acoustic signature.

Insulated header pipe from two boreholes are connected to a manifold using compression joints. The boreholes are plumbed in reverse return to share equal flow rate between both arrays. Kensa also supply above and below ground manifolds for ease of installation; if any connections are made below ground they must be electro fusion welded.

As soon as the connections are made from the boreholes to the heat pump the system can then be pressure tested, filled and purged. In this installation the anti-freeze has yet to be added, after which the system will be filled and purged in accordance with MCS guidelines.

Simple push fit connections or any mechanical compression fitting of your choice can connect the ground side pipework to the back of the Evo. The conveniently placed connections allow installers to join the system to the Evo from the top, rear, and side for ease of unit installation and compatibility with any site set-up.

Load side

Push fit connections are also used to connect the Evo to the load side (in this case underfloor heating). Compression fittings can also be used, push fit being preferable for ease of installation and removal if necessary in the future.

A diverter valve diverts flow out of the Evo into a three port valve to allow flow into the coil in the tank or the underfloor heating. The diverter valve is controlled by the Evo, and comes supplied with the unit.

Ed has installed a buffer tank and connected this across the primary heating flow and return in a diagonal fashion for maximum thermal destratification inside the tank.

Pressurising the system

The flexible hose can be used to connect the cold water mains supply to provide two separate fill loops: one for the load; one for the ground. Firstly it can fill and top up the load side of the system (underfloor). Secondly to top up the ground side, should it ever drop in pressure.

Separate fill and purge ports are located next to the incoming borehole pipes and shown here with the white cap ends. This is the point at which you would pump in your fresh water and then your anti-freeze. If using a subterranean or below ground manifold supplied by Kensa then these valves will be present.

Although the Evo’s touch-screen displays pressures and temperatures, as a recommended optional extra, Ed has added a pressurisation gauge on the ground side for quick observations.

An expansion vessel is installed to allow expansion on the distribution. The pressure can be viewed by the gauge on the combi valve. Again although the Evo touch-screen display has a pressure indication, for quick observations Kensa recommends the installation of a pressure gauge for convenience.

Control board

To remove the front panel of the Evo it is as easy as removing one screw.

Once the front panel of the Evo has been removed the top panel can then also be detached to access the control board. The Evo’s control board and touch-screen display comprise the ‘Genesis System Manager’, the world’s first system manager dedicated to ground source heat pumps, exclusive to Kensa, and launched with the Evo Series.

To gain access to the Evo’s control board two screws are removed.

Within the Evo’s control board can be viewed the on-board power meter which records the power consumption used by the unit (no control wires or power have been brought into the Evo at Ed’s installation as the building hasn’t yet progressed to this stage).

The Evo has a special feature “function tests” button which enables all of the controls to be tested by pushing buttons on the touch screen display enabling you to turn on pumps, valves, supplementary heating etc., a really useful feature.  It also comes with a link wire, so you can run and test the unit before all of your secondary wiring connections are completed.

Once connected the Evo’s control board can enable two heating set points, as well as the facility to control additional underfloor pumps if necessary, up to 2 amps. It also has a supplementary heating control and can also control an immersion to combat legionella. Amongst many other benefits the Evo has the option of using a weather compensation system.

Commissioning

Once connected the Evo is ready for commissioning. Thanks to the Evo’s intuitive Genesis System Manager installers can easily follow the commissioning process and set the unit to run. The step-by-step commissioning is usually carried out by the installer over the phone with Kensa and recorded on Kensa’s system, however the Evo is password protected for the installers benefit and can be commissioned easily by the installer alone.

The Evo’s control panel displays real-time CoP’s, ground and load side pressures and temperatures, and system mode. The imminent introduction of wi-fi connectivity to the Evo’s control board will allow remote control of the unit.

 

For more information on the Kensa Evo ground source heat pump visit www.kensaheatpumps.com/evo or for further details on this featured installation contact Edward Savage at epsplumbing@icloud.com .

Watch the installation in pictures

carbon monoxide threat

Carbon monoxide (CO) is often called the silent killer, as it is colourless, tasteless and odourless. At its highest concentration, it can be fatal, killing people in minutes. More commonly, those exposed to low levels experience flu-like symptoms like headaches, dizziness, tiredness, confusion and difficulty breathing, and/or side-effects akin to food-poisoning, such as nausea, vomiting and stomach pain.

According to CORGI HomePlan’s survey of 2000 homeowners in June 2015, 1 in 10 adults in Britain have experienced carbon monoxide poisoning to some degree in their home, and NHS Choices reports that 200 people go to hospital with suspected CO poisoning per annum, highlighting the scale of the problem.

All types of combustible fuel appliances whether old or new, including fireplaces and wood burning stoves, as well as oil-fired and LPG boilers, can potentially leak carbon monoxide. Ground source heat pumps are electrically-driven devices with no combustion, so there is no risk of this deadly gas being emitted.

In fact, ground source heat pumps produce no point of use emissions of any pollution: carbon monoxide (CO), carbon dioxide (CO₂), Nitrogen Oxides (NOx), Sulphur Oxides (SOx) or particulates, therefore helping to reduce air pollution and ultimately climate change.

Find out more about the environmental and health benefits of ground source heat pumps compared to carbon burning heating systems, here.

Overcoming Overheating with Ground Source Heat Pumps Video

Overheating is an issue that needs to be faced when looking at the design of multiple occupancy buildings. This video explores how “Shared Ground Loop Arrays” with ground source heat pumps can avoid the common overheating problems associated with district heating losses, and also provide passive cooling for free.

*Please note: the Non-Domestic RHI funding stream mentioned in this video has now expired. Explore other funding options here.
Passive Cooling with Ground Source Heat Pumps Video

Kensa’s ground source heat pump systems offer free passive cooling, whilst the ambient temperature of the distribution system further offsets any potential overheating. Passive cooling uses the low temperature of the ground loop to cool the property via a fan coil, which can be located in the main living rooms or bedrooms to provide comfort cooling in the summer.

*Please note: the Non-Domestic RHI funding stream mentioned in this video has now expired. Explore other funding options here.
ERP Ratings

Hot on the heels of the government’s Clean Growth Strategy, the Energy related Products (ErP) Directive that came into force across the UK and Europe on the 26th September 2018, legislates that boilers must not exceed a new lower threshold of Nitrogen Oxide (NOx) emissions.

In an effort to reduce pollution and improve air quality, oil-fired boilers with NOx emissions exceeding 120mg/kWh, and gas or LPG boilers with NOx emissions that exceed 56mg/kWh, can no longer be installed. These strict limits are applicable to boilers that are up to 400kW in size, however ground source heat pumps produce no point of use emissions.

This latest legislation follows on from the energy labelling initiative introduced in 2015, and is intended to help achieve the EU’s targets of lowering energy consumption by 20% and increasing the share of renewable energies by 20% by 2020.

Why NOx?

According to current estimates by the UK Health Alliance, outdoor air pollution contributes to around 40,000 premature deaths, over 6 million sick days and an estimated total social cost of over £20 billion per year.

Air pollution comes in three main forms: particulates; Sulphur Oxides (SOx); and Nitrogen Oxides (NOx). Nitrogen Oxide (NOx) is a collection of reactive and poisonous gases formed when fuel is burned at high temperatures; the higher the temperature, the more NOx will be emitted.

A ground-breaking solution

Much of this air pollution is caused by vehicle transport but there is also a contribution from combustion heating systems that burn gas, oil, LPG or biomass to produce heat.

A ground source heat pump extracts naturally occurring heat from the ground (or water) and is an electrically driven device with no combustion. There are therefore no point of use emissions of any pollution – particulates, NOx or SOx (and no point of use CO2 emissions either).

There are estimated to be 900,000 domestic gas boilers in London. If these were all replaced with ground source heat pumps, we could reduce the NOx emissions in our city alone by over 400 tonnes per annum compared to even the best gas condensing boilers.

Find out more about how ground source heat pumps can reduce air pollution, including NOx emissions, by watching this short video.

Stonewater Housing Site Footage

Posted by & filed under News, Social Housing.

Stonewater Housing Site Footage

Watch as Kensa Contracting contractors drill boreholes for a shared loop ground array system to provide affordable warmth for residents of Stonewater Housing.

Kensa replaced inefficient night storage heaters with ground source heat pumps in 29 properties in Burton Crescent and 26 properties in Burton Gardens in late 2017.

Read more about this Kensa Contracting project here.

Enfield Flats Tower Blocks From Space

England’s largest district ground source heat pump scheme is visible from space!

See two of the eight tower blocks that have been retrofitted with Kensa Shoebox heat pumps connected to shared ground loop arrays by Kensa Contracting.

Google Earth has captured the moment the borehole ground arrays had been installed with the ground recovery in progress, just prior to being re-turfed; view before and after shots of this ground-breaking ground source heat pump project!

Matt Trewhella, James Standley, Claire Perry, Sarah Newton

A Cornwall-based renewable technology manufacturer of ground source heat pumps, Kensa Heat Pumps Ltd, has hosted a visit from the Minister of State for Energy and Clean Growth, the Rt. Hon Claire Perry MP, and Conservative MP for Truro and Falmouth, Sarah Newton.

Coinciding with the publication of a Government response (19th July 2018) to boost the uptake of energy efficiency measures with upfront grants through the revised Energy Company Obligation (ECO), Kensa’s Ministerial visit affirmed the role of British manufacturing in the nation’s transition to a cleaner and greener low carbon economy.

Joining Kensa at their manufacturing facility on a former tin mine site, Mount Wellington Mine near Truro, Cornwall, Energy and Clean Growth Minister Claire Perry said: 

The UK is leading the world in cutting emissions, with the best economic growth while delivering the deepest carbon reductions of any G7 nation over last 25 years.

Continued government investment through the Renewable Heat Incentive scheme (RHI: this scheme has now closed – please visit this page to explore other funding) is supporting the scale of change needed to meet our 2050 targets for cutting carbon emissions from heating our homes and businesses, as well as boosting the local economy right here in Cornwall.

Yesterday’s changes to the flagship ECO scheme will increase the proportion of the scheme that is delivered with local authorities to 25%. Combined with the scheme’s new innovation requirement, this will help Cornwall County Council to work with Sarah Newton MP to give Cornish residents the ability to live warm and well.

Since the Energy Company Obligation scheme (ECO) was launched in January 2013, 2.3 million energy efficiency measures have been installed in approximately 1.8m homes, helping to reduce people’s energy bills and make homes more energy efficient. The announced changes to the ECO scheme single out ground source heat pumps as providers of long-term benefits with low running costs, and the only technology that is able to receive both funding through ECO and the RHI (this scheme has now closed).

Simon Lomax, Managing Director of the Kensa Group comments:

We are delighted that co-funding between the RHI (this scheme has now closed) and ECO will continue to be available for ground source heat pump installations.  By singling out our technology, Government is recognizing our long-held view that ground loops represent vital national infrastructure and are worthy of exceptional support.  We also are pleased to note that Government appreciates our shared ground loop system architecture allows the provision of lower cost district heating installations whilst providing connected households to select their own preferred electricity supplier.  Ground source heat pumps provide the lowest cost, lowest carbon heat and should emerge as the default choice for off-gas properties.

Sarah Newton, Conservative MP for Truro and Falmouth comments: 

Companies like Kensa are just what Cornwall needs more of – high tech, well-paid sustainable jobs in both manufacturing and contracting. Kensa’s renewable energy ground source heat pumps are found in buildings not just in the UK but are also exported as far away as Holland, France and even New Zealand.

Kensa is 100% home grown Cornish, and I’m pleased to visit once again, having been one of their biggest supporters over many years. Now employing over 40 people, today’s Ministerial visit provides a massive endorsement of Kensa’s continuing innovation and growth. But most of all I am proud that it is a Cornish company that is a market leader in solving fuel poverty, reducing heating bills to the lowest possible levels by providing Kensa’s ground source heat pumps to the poorest and most needy in society.

Simon Lomax continues:

With a long-standing mining heritage, Cornwall has a long history of utilising nature’s resources for the benefit of our economy. The changing tides of our nation’s approach to energy production has led to Cornwall reviewing its natural assets and identifying new ways to utilise these resources, resulting in Cornwall becoming one of the UKs green growth leaders. We are proud that Kensa is one of those sustainable businesses leading this revolution, all from a former mining site in the heart of the County.

With ground source heat pumps recognised as the most efficient renewable heating technology available, with no point of use emissions, ultra-low running costs, and the highest tariff available for heating systems through the Renewable Heat Incentive (RHI: this scheme has now closed – please visit this page to explore other funding) now able to be jointly co-funded with the amended ECO, the technology has been rightly singled-out by Government as significantly important in its achievement of its carbon reduction targets.

Kensa’s shareholders, directors and staff are proud that Kensa has pioneered the retrofit of ground source heat pumps into fuel poverty applications, especially in social housing, which continues to allow some of the poorest in our society to benefit from the lowest possible heating bills.

Today’s ministerial visit is a very positive step to ensuring the stability and sustainability – and locality – of the nation’s energy production.

Also present at the visit was HSBC UK, which has supported Kensa’s growth over the last five years, providing finance facilities to enable the manufacturer to invest in the latest sustainable heating technology and expand its business. Rob McPherson, HSBC Area Director for Cornwall, Devon and Somerset, commented:

Kensa is an innovative and forward-thinking company which is leading the way in the renewable energy sector and we’re delighted to have supported the business through this period of significant growth. HSBC is passionate about helping sustainable firms to achieve their goals and we’re delighted to have attended the ministerial visit today to demonstrate our ongoing support for the business.

Shared Ground Loop Arrays

Ground source heat pumps don’t have to follow the traditional ‘one heat pump, one ground array’ route. If you have two or more domestic properties on one site, you can link them together with shared ground loop arrays.

*Please note: the Non-Domestic RHI funding stream mentioned in this video has now expired. Explore other funding options here.