AV Dawson is a truly multi-modal provider offering logistic services including road transport; rail freight; quayside loading and unloading as well as warehousing and storage, all from their Teesside Hub. With a dynamic road fleet, a choice of rail terminals and shipping berths they provide effective and cost efficient solutions for the transportation of a variety of conventional & unconventional cargo's.
The client was given a specific challenge which was to be able to keep the inside ambience of a cladded building at a safe level to store valuable steel coils for the automotive industry. The minimum temperature of the “indoor climate” could not be allowed to drop below 14 DegC in winter and could not be above 65% relative humidity at any time!
If the steel was allowed to be cold, when it reached the warm car factory the steel could potentially sweat and moisture could form on the surface causing corrosion rendering the stock useless. With a stock value in excess of £15,000,000 this was not an option.
AV Dawson started the process of looking for the best solution early in 2014 as the building ground works started. Considerations were made for a renewable source of energy to facilitate their needs. They investigated several different avenues including biomass boilers, high efficient gas boilers and even the waste heat from a neighbouring anaerobic digester plant. They needed a reliable source of heat available 24 hours a day, it had to be a low energy usage solution with minimal servicing and maintenance. The system must have the ability to react quickly and sustain its output during high demands such as when doors are opened during trains and wagons entering or leaving the shed.
The system would need to be housed inside the building but as space was a premium, there was limited area for any system to be installed. The installation had to be completed by October 2014 to allow the first shipment of steel from TATA.
This meant the entire build from start to finish would take 208 days!
The climate of the building would need to be controlled with air handing units capable of moving the entire shed’s volume of air to remove humidity and maintain a constant temperature across the 264m length. The system as a whole would need to be easily controllable by the facility staff but automated so it could react fast enough on demand. The system had to have historical data and trending, notifications and alarm functionality to give full visibility to the client and maintenance staff.
There was only one solution which could match and exceed this remit.
HT Energy Ltd designed a solution using NIBE Ground Source heat pumps to more than satisfy the client’s requirements. They worked closely with Drapervent who supply air handling units to create a proactive heating/dehumidification system.
Energy calculations were formulated and a specification was delivered by HT Energy to match the required energy. There was a full geological survey produced to estimate how the ground below the site could support the energy extraction needed for the system to work efficiently. It was found that the water aquifers had a tidal effect and could supply plenty of energy day after day. In fact it was found that the incoming temperatures rarely dropped below 9DegC over the winter months. This meant the heat pump’s efficiency was very high. To maximise this effect we designed a closed loop bore-hole array which was deep enough to take full advantage of the water movement below ground. There are 70 x 150m deep bore holes located across the entire length of the building.
One of the crucial design aspects of the system was that the heat and climate control had to be even across the building. To create this even spread we placed 10 stand-alone systems along one side of the building. Each one comprised of a NIBE F1345-60kw unit with a 500 litre buffer store tank to reduce cycling and starts/stops. Therefore we had 600kw of output ready to deliver.
As the UK strives to reduce carbon and energy consumption in conjunction with Government targets we at HT Energy Ltd understand the crucial link between energy and carbon.
In this design and installation the three main factors looked at in order to reduce energy and carbon were:
Design – ensuring the design meets the end users needs, demands and requirements
Installation – ensuring a high installation standard to improve efficiency and reliability
End user controllability – in order to reduce energy and carbon from heating systems the crucial link is end user controllability, as controllability brings greater efficiency
The user controls were integrated to provide the end user with a fully controllable, simple to operate system, from that of a complex and challenging installation. By integrating a number of ground source heat pump systems together to form a building wide solution, whilst also providing end user with the education provided a simplistic approach to controllability. This is essential in order to ensure that energy reduction, carbon reduction, client satisfaction and understanding was able to be obtained by the end user. Without such an approach projects of such a nature can lead to negative responses, however in projects such as this nature bringing such controllability using the NIBE new gen control and Uplink adds additional advantages at end user level.
The estimated energy demand for the building was 2,038,680 kwh/year
The estimated energy usage for the GSHP systems was 558,542 kwh/year
This offers a saving of approx. £34,000.00 per year (gas @ 5p/kwh, elect @ 12p/kwh)
This also means a huge reduction in carbon emissions of 300 tonnes per year by not burning fossil fuel.
The Seasonal Performance Factor of the installation was calculated as an average of 3.65 SPF with an actual figure of 3.64 SPF after 6 months therefore well on track to achieve the desired performance and efficiency.
Each of the 10 systems was fitted with their own heat meter and electrical energy meter to monitor the amount of energy each GSHP system produced and used. This meant that an accurate account of running cost and efficiency could be kept by the client and the maintenance staff.
This is also a requirement by Ofgem for the Non-domestic RHI tariff.
The 1345 Heat pump controllers incorporate internet connectivity to allow full control and interrogation of the heating and hot water system from anywhere in the World. It gives the customer and the service engineer a valuable tool to monitor the running of the entire system and it even emails when there is an issue to look at.