Friday, 29 July 2016

Zero hour

Following the publication of Guide B early in July Matt Snowden, Communications Executive of CIBSE, explores the new Guide's Part 0, the rationale behind it, and how it could affect the industry as a whole.

To use a tired old metaphor, writing CIBSE guidance is a bit like painting the Forth Bridge. Or it would be, if engineers hadn’t solved that problem too by using a pioneering new glass flake epoxy paint to ensure the famous crossing doesn’t need another coat until 2031. It’s this same constant engineering innovation that necessitates revision of CIBSE Guides to ensure they always stay as up to date as possible with the latest changes in technology and legislation.

Such is the case with Guide B which, until it was launched earlier this month, hadn’t been totally replaced since 2001. Obviously a lot has changed since then, and even since its last update in 2005 there have been fundamental changes in the industry – the European Energy Performance of Buildings Directive (EPBD), for one. As a result, the Guide which has been nearly a decade in the making has been comprehensively updated.

Among the new revisions are heat networks, included as a result of the Government’s support of the technology, and Guide B4 on Vibration Control – which is designed to help engineers keep projects within acceptable noise limits. One of the most interesting new additions to the Guide however, is part B0 (so named to avoid upsetting the numbering), because of the reasoning behind its inclusion.

For a start it’s a first for CIBSE in that it’s an online-only part of the guide, set out to highlight features that are specific to, or particularly important for, a wide variety of activities. In its current version, the chapter features activities and building types including: offices, dealing rooms, supermarkets, commercial kitchens, and farms. Drawing on CIBSE’s vast pool of knowledge that touches every conceivable application of building services, the intention is to make this online section a living thing that can be added to and revised much more frequently.

But why the change? Dr Roger Hitchen, chair of the Guide’s steering group and author of the chapter had this to say: “The inclusion of Part 0 to the new Guide has been driven by changes we have seen in the industry, which has seen more and more engineers join building services from other disciplines or more general engineering degrees. The intention is to make this transition easier and to make their future work more effective by helping them to understand the issues created by different contexts, and their relevance to HVAC design.”

Part 0 covers many different applications, from kitchens to farms
This, then, is an example of the practical application of collaboration in action. By making it easier for engineers from other disciplines to contribute to, and benefit from, CIBSE’s knowledge we are helping to spread the ideals of best practice and sustainability across the whole industry and beyond. In return, we are benefitting from the experiences of other industries to make our own perspective broader and the knowledge we provide more useful.

No engineer can be a font of all knowledge, even within their own industry, and it’s not realistic to expect individuals to know everything about every facet of a building project that they might be working on. What this does instead is to give a grounding in the basics of HVAC design – the considerations and unique features of each unique situation. This helps non-experts to at least ask the right questions, to know what to consider in a design and to take the needs of building services into account when designing a building.

A part of a building that may have been a source of annoyance for an architect suddenly makes sense in light of what they might learn from Part 0. Understanding why that feature exists and why the engineer has done what they have might even allow another professional to step in and suggest another way of fixing the same problem that draws on their own experience in their industry.

A broad understanding of another profession's work encourages joint
working and creative problem solving
As a result of this, we will be helping to end the disconnect between the different professions involved in creating a building and helping them learn from one another. At EcoBuild this year, Past-President Nick Mead said that “Engineers and Architects must learn to work together, or neither will get what they want”. While this is true, Part 0 of Guide B is taking that idea one step further: Engineers must work with every stakeholder, and every stakeholder must work with engineers. By adapting principles from each other’s disciplines and truly understanding each other’s objectives, we can all ensure we are pulling in the same direction.

Friday, 22 July 2016

Small is beautiful

A year after CIBSE installed a micro CHP system in its Balham headquarters, we look at a report by Dr. Alem Tesfai, Fuel Cell Systems Research Associate, Dr. Anastasia Mylona, CIBSE Research Manager, and Professor of Chemistry at the University of St Andrews Prof. John Irvine to see how it's been performing and what we've learned about the technology, in this week's blog.

With recent advances in currently avaliable SOFC micro-CHP technology, the use of fuel cell micro-CHP systems has the potential to be an efficient and reliable way to provide heat and power in office buildings. In early 2015, CIBSE acquired and installed a Solid Oxide Fuel Cell (SOFC) micro CHP system at its headquarters in Balham, London; a converted and recently renovated Victorian town house.

The increasing demand for industrial energy due to economic growth in developing countries, as well as increasingly energy-intensive domestic lifestyles, is posing a serious environmental challenge as well as a financial one. The problem of whether these competing demands for energy can be satisfied in a future of shrinking fossil fuel resources and global warming is of serious concern. This is especially true in countries like the UK where domestic and office heating is a major user of electricity, and it's something CIBSE has been addressing recently with its codes of practice on Heat Networks and Surface Water Source Heat Pumps, but could new technology hold the key?

CIBSE's Balham HQ in 2015
In recent years, this concern has intensified the search for more reliable and sustainable energy sources. Fuel cells have been proposed as the most efficient way to convert Hydrogen, or hydrogen rich hydrocarbons, to heat and power at the point of use for decentralised stationary power systems and for transportation. The efficiency of fuel cells stems from the fact that, unlike the conventional fossil fuel power stations where there are many intermediate energy conversion steps, the conversion of the chemical energy in the fuel cell system takes place in a single step. Avoiding these intermediate steps reduces the irreversible losses of energy to the atmosphere and enables fuel cells to achieve efficiency in the region of 40–60%.

Combined Heat and Power (CHP) is the simultaneous production of electrical and useful thermal energy from the same primary energy source such as oil, coal, natural and liquefied gas, or solar. A variety of micro-CHP systems are currently available, or under research and development. Some of these micro-CHP systems include steam turbines, reciprocating internal combustion engines, combustion turbines, micro turbines, Stirling engines and fuel cells. Fuel cell systems have become the focus of interest due to their high electrical efficiency, and their ability to provide a low heat-to-power ratio means the system can run at high electrical and thermal efficiency throughout the year.

Though early in market entry, fuel cell micro-CHP systems for residential and small commercial applications are the focus of interest as the prime mover technology for micro-CHP systems. These products could be used to meet the electrical and thermal demands of a building for space heating and domestic hot water and, potentially, for absorption cooling. In comparison with all the other existing technologies, SOFC-based micro-CHP systems would have a better performance. With its high electrical efficiency, over 50%, and low heat-to-power ratio it offers significant benefits, effectively supplying the total electrical demand of a building throughout the year.

The two 1.6MWe natural gas CHP engines at
The Pimlico District Heating Undertaking
CIBSE has installed a SOFC based micro-CHP system for testing and demonstration purposes. Fuel Cell micro-CHP for residential and commercial building is a new technology in the UK, but well established in other markets such as Japan and Germany. Due to commercial secrecy and low production volumes, information on historical and current prices for fuel cell micro-CHP is not widely disseminated. However based on our research in UK and other markets, currently 1kW fuel cell micro-CHP cost about €16000 at the moment, the equivalent of around £13000. Achieving mass production and technically advanced durable product, is expected to reduce the price, possibly to about €6,000/£4,500 by the year 2020.

Several Fuel cell micro-CHP products were compared, with the main criteria chosen being performance and reliability, as well as availability and the supplier’s previous experience. Although overall system performance and viability was compared, there was no independent data to compare any of the fuel cell micro-CHP systems.  Therefore the selection process was mainly based on the company’s ability to supply and maintain the system. System upfront cost and a good technical support system were also factors for choosing the product.

The micro-CHP system generates 1.5kWh electricity and about 200 L/day of hot water, reducing both heat and power bills. The high electrical demand at CIBSE HQ of 25 kWh means that the electricity generated by the SOFC-micro-CHP system is all consumed and there is no need for exporting to the grid. Also, the 200 L/day of hot water generated from the system is used to cover most of the 250 L/day domestic hot water demand at CIBSE HQ.

Based on the experience gained at CIBSE there are three key issues that need to be considered before embarking on the installation of the SOFC micro-CHP system:

  • The base load power requirement of the building (the minimum level of electricity demand)
  • The domestic hot water requirement of the building
  • Can the system be safely and efficiently integrated with the buildings current system or will it be a replacement to the current system?
Unused electricity can be exported to the grid

The system providers can help in developing a business case which will consider the heat and power demand of the proposed building. It is critical to explore different options for plant layout with as many system installers as possible with the aim to minimise the installation time and cost.

Key requirements for the SOFC micro-CHP installation:

  • Natural Gas: The building will need to be connected to a mains gas supply
  • Electricity: The building will need to be connected to the electricity grid at all times – as the electricity that is not used is exported to the grid

  • Water: The building will need to be connected to mains water
  • Internet: Connection to the internet is required for unit control/monitoring

Friday, 15 July 2016

The 12 per cent

Welcome to the second #Build2Perform, the CIBSE podcast. Last week we discussed Green Sky Thinking Week and the future of sustainability - this month, we're talking about women in engineering and National Women in Engineering Day, organised by the Women's Engineering Society. Join Matt Snowden, Sara Kassam, Juliet Rennie and Susie Diamond, and check out some of the resources below

Remember, you can also find the podcast on the iTunes app so you can download it and listen on your commute, and you can find news and discussion of the topics covered by looking up @CIBSE on Twitter or searching #Build2Perform

In the second #Build2Perform podcast we discussed women in building services engineering and women in Science, Technology, Engineering and Mathematics - where women make up just 12.5% of the active workforce.

Some useful resources:

  • The Women's Engineering Society is a charity and a professional network of women engineers, scientists and technologists offering inspiration, support and professional development. Working in partnership, we campaign to encourage women to participate and achieve as engineers, scientists and as leaders.
  • National Women in Engineering Day was set up by the Women’s Engineering Society (WES) to celebrate its 95th anniversary. The idea behind National Women in Engineering Day is to encourage all groups (Governmental, educational, corporate, Professional Engineering Institutions, individuals and other organisations) to organise their own events in support of the day.
  • The Women in Building Services Engineering (WiBSE) network aims to support and encourage women joining, working, staying and progressing in the building services industry. They work to increase the number of women choosing a career in all sectors of the building services industry, to support those already in the industry to enable them to achieve their career goals and to encourage more women to join the Institution and contribute to its governance and activities

Friday, 8 July 2016

In hot water

May's launch of the Surface Water Source Heat Pumps code of practice by CIBSE, and produced in association with the Heat Pump Association (HPA) and the Ground Source Heat Pump Association (GSHPA), marks the second such code released by the Institution in a new venture. To explain the logic behind the launch Phil Jones, Chair of the CIBSE Energy Performance Group, writes on the current situation.

The UK is under huge pressure in the coming years to solve its energy dilemma. As prices rise, security falls – and the effects are being felt in homes and businesses alike: a quarter of the UK’s energy is used by homes, and the majority of that goes on heating them. But rubbing up against this problem is sustainability: the traditional energy sources of oil, gas and coal are great polluters, and the UK Government is rightly attempting to cut its use of these to combat climate change.

Here, the UK has an underutilised secret weapon – its network of rivers, streams, lakes, canals, and its massive coastline. The environment has long been thought of as a largely untapped potential source of heat, with ground and air source heat pumps taking the limelight, but water source systems remain less popular - despite their advantages.

The UK has a large network of rivers, canals and lakes with habitation
suitable for a SWSHP system
As with any engineering solution, the goal is to overcome problems with the best use of the tools available – whether that’s using a closed loop system in a lake, an open loop abstraction approach in a canal or a river-based system to heat or cool a building. The primary consideration for such a system is the sustainability of the project in the long term, which is the technology’s primary advantage. This will bring future cost savings, as well as a positive impact on the environment through fossil fuel savings.

Heat pump systems can also be used to heat and cool simultaneously – this removes the need for separate heating and cooling systems and makes the overall process much more efficient. Rather than generating new energy or wasting surplus energy, the energy that has already been generated can be used again – which raises an important point about sustainability: It is about considering the lifetime cost of a building, not just the short term, and the savings in operating and maintenance that can be achieved with a properly commissioned Surface Water Source Heat Pump (SWSHP) make the system worth the capital cost of installation.

There are also savings to be had in the equipment you don’t have to buy – for example, if used in place of a conventional gas boiler, there is no need for additional infrastructure such as the gas mains supply and the flue. Water also has inherent advantages over other materials for storing heat – it has a much greater capacity for heat storage than air, and the average canal or river’s temperature is greater than the ground, making a water-based system a stand-out option for those with access to a natural supply.

The SWSHP system at Kingston Heights in Surrey
These benefits are all well and good, but the crucial caveat is that they require a well installed system backed by industry knowledge in order to make them work best and provide the greatest benefits to their user. This growing industry has been crying out for concrete guidance and high standards that will cement the status of the SWSHP as a well-regarded and feasible option for buildings new and old going forward.

This new code of practice is a significant step forward, but it will require continuous work to improve and update the document going forward in order to ensure professionals have access to the best and most up to date information. It is also important to remember that we can only do so much with research and paper – the key is to get the information into the hands of professionals through training, and CIBSE and GSHPA have set up training courses to make sure there are trained people are out there pushing good SWSHP installations.

If we can do this, we can ensure that SWSHP systems represent a sustainable solution for the whole life of a building for years to come.