We were proud to have been nominated for the Regional Small Scale Project of the Year at the South West Energy Efficiency Awards, for our work for the Anglo American Oil Company. Read on for an overview of the project.
The project background
Anglo American Oil Company is a company specialising in oils and fuels for motor racing and small engines. It recently introduced a new fuel that massively reduces harmful emissions in two-stroke machinery, typically for horticulture and forestry applications. The Anglo American Oil Company has set up its main offices and warehousing in new buildings on ex-MOD land near Poole in Dorset.
The Swedish Managing Director/owner wanted the offices and workshop to be heated and cooled as comfortably, efficiently and in as environmentally friendly a way as possible – without sacrificing any of the qualities expected in a contemporary new-build project. The main contractor, Jade Aden, is a very well respected local developer with a long track record of building top quality commercial properties. The Anglo American Oil Company buildings in question are the main offices, running to 342 square metres across 2 floors and a workshop/laboratory of 171 square metres. A large adjacent warehouse is unheated and outside the scope of works.
The brief was for a no-compromise heating and cooling system:
- RHI eligible as far as possible
- Maximum use of renewable sources for the energy requirement .
Particular consideration was to be given to creating a work environment that promoted high levels of productivity in the office area – so temperature control and air quality were key. The main contractor did not have experience of a brief as specific as this and H2ecO was brought in by the client approximately three months before planned completion. The main building fabric design had already been fixed and was fortunately already to a high standard of U-Value. Typical entire-site electrical load in normal daytime operation was estimated at 30kW. The client wanted to avoid any requirement for a mains gas connection.
Based on personal experience in Scandinavia, the client wanted underfloor heating for both the office and the workshop.
- Office Heating and cooling whilst remaining RHI-eligible?
- Maintain a healthy, productive workspace.
- Underfloor heating in a workshop with structural high load slab.
- Being ’imposed‘ on the main contractor by the client.
- Minimising demand from the grid.
1. Office Heating and cooling under the RHI.
At a very basic level, heating is best done from the floor as heat rises and cooling is best done from the ceiling as cool air sinks. Radiators round the perimeter of large offices create very patchy temperatures with over and under-heated zones. Both from a comfort and efficiency point of view, UFH is optimal – but not normal in UK commercial steel-frame buildings.
Technologies also capable of cooling are not allowable under the RHI so the use of, for example, Daikin VRV IV Heat Recovery air conditioning systems alone was not possible due to their ability to heat and cool at the same time. A solution that used an RHI eligible heating-only technology interlinked with a heating and cooling technology was the end result. H2ecO opted to use all-Daikin equipment to maximise compatibility but there was no off-the-shelf solution to achieve what was required. In collaboration with the Daikin UK design team, a system utilising a 16kW Daikin Altherma Low Temperature heat pump to provide whole-building heating via in-slab underfloor heating was specified – in conjunction with a whole-building Daikin VRV Heat Recovery air conditioning system. The underfloor heating pipework was installed by H2ecO with a standard screed covering in the office building. Work was carried out over weekends to minimise disruption of the main contractor’s established schedule. The two systems would have been capable of “fighting” each other so H2ecO devised an interlock control for each zone to ensure the systems would not compete. This method was a first for Daikin UK and one they may use in future elsewhere.
The VRV Heat Recovery system, with an 8hp condensing unit and six-way multi BS box, uses Daikin FXFQ-A Roundflow cassettes and FXZQ-A 600 square four-way blow cassettes to provide mainly cooling (best done from above) but they are also able to provide quick response heating if required. This latter was an extra part of the brief as the client wanted to allow for a Christmas shutdown of two weeks where the building temperature would be allowed to fall significantly to save energy but then be warmed up quickly when the facilities reopened. UFH systems are not fast response so could not meet this part of the heating brief alone.
The system controls allow the UFH powered by the RHI eligible Daikin Altherma unit to provide most of the facility’s heating demand – more than 98%. This means the client can claim RHI payments for most of the space heating and domestic hot water. At the same time, the Daikin VRV system provides an additional layer of fast-response heating – alongside humidity control and cooling when required. The VRV Heat Recovery technology also allows efficient, economical transfer of ‘waste’ heat from warm areas to colder areas – rather than simply wasting it to the atmosphere.
2. Maintain a healthy, productive workspace.
The client expressly wanted to avoid the example that most of us have experienced – rooms that make everyone drowsy when they have been full for a period of time and the CO2 levels start to rise because there is no fresh air provision.
In addition to the heating and cooling equipment, H2ecO specified and fitted a Daikin Heat Recovery Ventilation system for the main spaces. This allows the extraction of stale, warm air and the return of fresh air – pre-heated in a heat exchanger. This is vital to the provision of high quality air with normal CO2 levels in busy rooms. The meeting room, which is a relatively small space with significant solar gain and can be very densely occupied, has been a particular success: even when the room is full, both the temperature and air quality remain excellent.
Although a Daikin Heat Recovery Ventilation system can be operated autonomously, H2ecO specified that the Anglo America Oil Company unit be linked to the rest of the development via Daikin’s i-Touch Manager – intelligent central control system – which allows the setting of seasonal profiles to maximise efficiency.
3. Underfloor heating in a workshop with structural high load slab.
This requirement raised most eyebrows with the main contractor! The workshop was to be used as a storage and workshop area with a 2 post 5 tonne car/van lift and had a full height roller shutter external door. The brief required Underfloor heating so that workers lying on the floor to work on vehicles would not get cold. The floor slab had to be structural and able to take substantial loads. Equipment had to be bolted down to it and the heating system had to be able to cope with the opening and closing of the large area roller shutter.
The solution was to install a floor slab with 100mm of solid insulation under the reinforcing mesh and then fix the UFH pipework at smaller than normal centres to the reinforcing mesh to allow more rapid heat transfer. The concrete slab was then applied with a minimum thickness of 150mm over the pipework. The known position of the vehicle lift floor fixings was avoided with the UFH pipes allowing them to be fixed to full depth.
The result has been a slightly surprising success. The RHI-eligible 16kW Daikin Altherma heat pump has coped in line with calculations and the fact that the slab has such a large thermal mass means that opening and closing the roller shutter door has a minimal, short term effect on the temperature of the building. The warm floor is a resounding hit with staff who don’t suffer with cold feet and legs (or backs) even in the depths of winter.
A post-installation survey with H2ecO’s FLIR camera has shown an almost completely even spread of heat through the thick concrete slab rather than the individual pipes emissions that can be seen through a normal thickness screed. The thickness of the slab has not adversely affected heat flow into the building due to the insulation below and actually seems to have acted positively to stabilise temperature fluctuations.
4. Being ’imposed‘ on the main contractor by the client
This was a major concern for H2ecO when the client approached the company. Main contractors typically have an established pool of sub-contractors who they know and trust. Having a new sub-contractor imposed on them by a client – especially quite late in the design stage – is not usually a good recipe for a stress-free project.
Having identified the potential issue, H2ecO made a particular effort to develop a close working relationship with the project manager and the site agent. This went well beyond the usual provision of statutory paperwork and method statements etc. H2ecO’s flexible work ethic and an understanding that by being brought in late in the development process it would have to work round the existing timetable helped to smooth any issues raised by the additional works required compared to a ’standard’ build of this type.
At the same time it has to be said that Jade Aden’s site team was excellent – and became genuinely interested in the technologies and systems being fitted into the building. The end result was a very smooth development process with no scheduling or specification problems at all.
5. Minimising demand from the grid.
The heating and cooling technologies selected for the project were the most efficient available at the time but they still require electrical power to operate. In order to offset as much of the electrical demand as possible the project was equipped with a 30kWp Solar PV array.
Due to the schedule, there was not time to get a full National Grid approval in advance so the client took the decision to install but not connect the array at risk (so that the installation could dovetail with the main build schedule). The National Grid approval was subsequently gained and the system connected. The Inverter system chosen was a Solar Edge system which provides panel-level monitoring and the ability to link with the TESLA battery storage system should the client decide to use such a technology in future for grid failure protection.
PV Predicted energy production = 24,950kWh using Government standard SAP methodology.
PV actual in first year = 30,000kWh
Result is 20% ahead of predictions.
RHI eligible heating in Offices
Heating energy consumption for space heating and domestic hot water over one year: 23,990kWh
Electrical energy consumption over 12 months (including full winter period): 6,041kWh
Cost: 2.5p/kWh heat energy produced
The renewable element of the heat produced is about 75%.
At the non-domestic RHI rate of 2.57p/kWh, the heating would actually cost Anglo American Oil Company just 0.6p/kWh for 20 years if they were paying for the electricity from the grid. Better still, the electricity comes from roof-mounted photovoltaic panels that produced more that 30,000kWh of electricity during the review period.
RHI eligible heat in Workshop
Heating energy consumption over one year: 17,187kWh
Electricity consumption: 4,192kWh
With photovoltaic generation taken into consideration, Anglo American Oil Company is effectively running its heating systems in the office and workshop for free over the next 19 years. And as the systems consume only 10,200kWh of the 30,000kWh produced, electricity costs over the whole site are significantly reduced – with potential for income from exporting surplus capacity to the National Grid.
Improvements for next time
- We used a steel volumiser vessel with the heat pump water circuit. Even when properly inhibited, it colours the water, which affects the visibility of the flowsetters on the UFH manifold. H2ecO now uses bespoke stainless steel volumisers manufactured in the UK to prevent this.
- The room housing the Hydrobox, DHW cylinder and Solar PV inverters was initially specified to be a store room and as such was not temperature controlled. It was later decided that it would house a computer server. The room was inadequately cooled for a server and a retrofit cooling solution had to be added. In future, it will be made very clear at the start of the design process that the room containing the key components will either be warm or will need specific cooling.
- Try to get involved earlier in the process!
“Working with Daikin UK, H2ecO designed and installed systems that fully met our requirements and are producing excellent results in terms of energy efficiency, economics and environmental performance. We are able to enjoy high standards of workplace comfort with minimal net running costs and negligible carbon footprint.” Anglo American Oil Company
“H2ecO has been a Daikin customer for four years, and has used its engineering expertise to design and specify Daikin systems exclusively as it grows its renewable heating business alongside its solar PV activities. H2ecO is now a Daikin Key Partner and supports Daikin UK’s Field Service Department in the Dorset area. The use of our equipment in this novel way at the Anglo American Project signals what we hope will be the start of an increase in the use of Renewable energy heating systems in commercial buildings of this type.” Daikin