Heat Pumps and Heat Waves: How overheating complicates ending gas in the UK

by Dr Aaron Gillich | Associate Professor and Director of the BSRIA LSBU Net Zero Building Centre

We have entered what many are calling the decisive decade on climate action. Among the most critical decisions that the UK faces this decade is how it will eliminate carbon emissions from heat. Heat accounts for over a third of our emissions, and over 80% of our buildings are linked to the gas grid. There is no pathway to Net Zero that doesn’t include ending the use of gas as we know it in the UK.

Given the size of the UK gas grid, no single technology or energy vector can replace it. We will need a combination of clean electricity and carbon‐free gas such hydrogen or biogas, delivered by a range of enabling technologies such as heat pumps and heat networks. And of course an extremely ambitious retrofit agenda that reduces the demand for heat in the first place.

The UK is investing widely in low carbon heating innovation. That innovation is essential, but is also unlikely to include any blue‐sky breakthroughs that aren’t currently on the table. In other words, the menu of low carbon heating technology options is set, and this decisive decade will be about deciding what goes best where, and how to ensure a just and equitable heat transition.

Low-carbon heating options

Of all the low‐carbon heating options available, low carbon heat pumps are the most efficient and scalable option that is market ready and can respond to the urgency of climate change this decade. The UK has set a laudable target of installing 600,000 heat pumps per year by 2028. Many have criticized this figure as unrealistic, but I believe that the target is highly achievable, and represents a pace that is in line with past transitions such as ‘the Big Switch’ that put us on the gas grid in the first place.

This race to replace gas in the UK has been widely discussed. As have the many barriers that face heat pump deployment in the UK. What I’ve heard discussed far less are the links between heating in the winter and overheating in the summer. Over the next decade, the end of gas will present both a threat and an opportunity to improve both the winter and summer performance of our building stock.

The threat of climate change is clear. The end of gas increases this threat because gas has allowed the UK to obscure poor building performance, and poor building knowledge for so long. Cheap gas has enabled a ‘set it and forget it’ approach to many building systems, and allowed us to maintain reasonable standards of comfort in most buildings despite very poor fabric performance. The irony is that this poor winter performance actually helps reduce the risk of overheating in the summer, as the leaky and poorly insulated buildings can more easily shed excess heat. It has been widely reported that many newer, better insulated buildings actually face an increased risk of summer overheating.

Replacing gas with heat pumps, or any other low carbon heat source, should be accompanied by ambitious retrofit to improve energy efficiency and reduce heat loss. There are many that argue heat pumps in fact require extensive fabric retrofit in order to function in most UK buildings. This is highly debatable and will be explored in detail in follow-up writings. Regardless, demand reduction and a fabric first approach is a good idea for its own sake.

Replacing gas with heat pumps, or any other low carbon heat source, should be accompanied by ambitious retrofit to improve energy efficiency and reduce heat loss.

But reducing the heat loss in winter will likely trap heat in the summer, presenting a conflict. The UK currently experiences over 20,000 excess winter cold deaths and around 2,000 heat related deaths in summer. It was previously thought that the increased temperatures from climate change would decrease winter cold deaths, but more recent work has shown that due to the increases in extreme weather events at both ends of the spectrum, it is far more likely that winter cold deaths will remain at similar levels, and summer heat deaths will increase dramatically under climate change.

We must use the transition from gas to low carbon heating as an opportunity to better understand our buildings. Many of 600,000 heat pumps we install by 2028 will be in new build, but up to half will need to be from existing homes.

Retrofitting a heat pump is also the time to think about not only how to improve energy efficiency for the winter but how to reduce summer overheating as well. Despite much effort towards a whole‐house approach to retrofit, most work remains quite siloed. Energy efficiency and heating installations are largely in separate supply chains, and the building physics knowledge to carry out an overheating risk assessment is even less likely to sit with the same project team. Overheating is also very poorly captured by the building regulations and planning process.

A holistic approach

The last few years has seen a growing awareness of overheating risk and an emergence of increasingly easy to use assessment tools. A very small fraction of UK homes have comfort cooling. Retrofitting a comfort cooling solution typically requires costly and complex changes to distribution systems. However, there are a range of low cost options, including using local extract fans to create interzonal air movement, or using night purges and thermal mass. Blinds are also incredibly useful, but often misused in summer, and can also help reduce heat loss in winter. There are also ways to use local microclimate features such as shaded areas or the North side of the building to bring in slightly cooler air from outside and reduce peak temperatures.

Improving the air tightness and fabric performance of our buildings to address heating in the winter will change how we implement these solutions for the summer. They require not only careful thought at the design stage, but also strong communication to help end users operate them properly. Simply opening a window is unlikely to help if the outside air is warmer than inside.

A significant problem is that there are insufficient drivers to force this type of holistic approach to design, performance, and communication. It is so often said that we need stronger policies in the area of heat and retrofit, and this is no doubt true. But while we await these policies it is incumbent upon each of us in this sector to share and collaborate as widely as possible, and use whatever influence we have over a given project to encourage a fair and forward looking solution.

In summary, the availability of cheap gas has allowed us to escape having to understand our buildings in much detail. Climate change is the catalyst for an untold level of change in our lives that we are going to start to truly experience in the coming decade. Heating and overheating are coupled issues that must be solved together. We must use the end of gas as an opportunity to understand our buildings better, and implement solutions to climate change that work across seasons, or we risk trading one problem for another.

In summary, the availability of cheap gas has allowed us to escape having to understand our buildings in much detail.

UK heat pump market has weathered Covid-19 challenges. Coherent policy support is now needed to unlock its full potential.

by Krystyna Dawson, BSRIA Commercial Director

BSRIA has released its latest global heat pump market reports, including the eagerly awaited report on the status of the UK heat pump market.

Last spring, deep uncertainty set in across the markets as lockdowns in many countries disrupted trading. There was fear within the heat pump industry of a significant slowdown in what had previously shown dynamic market growth.

Indeed, the global heat pump market posted a decrease of 1.5% in 2020. However, performance varied across regions: with 12% market growth year-on-year, Europe has been at the forefront; the UK also saw positive development with heat pump sales increasing by 9.2% in 2020.  

Green Homes Grant

UK heat pump market sales were helped by the RHI and the Green Homes Grant scheme in 2020. The latter has proven to be important for the market, which has seen sustained growth in the refurbishment segment despite the number of installations in new buildings stalling due to the lower level of new home completions.

However, heat pump installation still represents a major challenge in existing homes. The ongoing review of Part L and Part F of building regulations offer hope that refurbishments in homes and buildings will be conceived with low carbon heating in mind, but the review’s outcomes are yet to become a legal requirement.

Moreover, even though there is market potential for a higher number of heat pump installations in existing homes, the government has, so far, been unable to unlock it. The Saturday 27th March announcement of the closing of the Green Home Grant scheme to new applicants by 31st March 2021 has been yet another example of the disappointing approach to deployment of energy efficiency measures and heat pumps.

UK heat pump market: Achieving a net zero carbon economy

Heat pumps are among the technologies the government has identified as key to achieving a net zero carbon economy by 2050. The Prime Minister’s 10 Point Plan for the UK Green Industrial Revolution includes the target to deploy 600,000 heat pumps a year by 2028.

The UK saw around 37,000 heat pumps sold in 2020. The extra £300 million in funding, moved from the soon-to-be defunct Green Homes Grant to local authorities to enable energy efficiency upgrades for lower income households, may bring additional installations. But even if all 30,000 applicable homes were fitted with heat pumps, the numbers are insufficient to sustain hope of reaching the PM’s ambitious target.. There is potential for more heat pump installations in existing homes, and the interest in heat pumps is growing among home and building owners. The heat pump industry is also working at full speed to deliver innovative products that respond to end-user expectations and environmental challenges.

HVAC industry skills gap

However, unless demand from existing homes and buildings is unlocked at full scale, and until real attention is paid to the sufficient availability of a skilled workforce, the heat pump market will struggle to see the acceleration needed to reach the government target and make a difference in the level of carbon emissions from UK homes and buildings.

Coherent policy and financial support are needed to match the readiness to act on both industry and consumer sides. Integration of heat pumps in a home or a commercial building requires a holistic approach where design and affordability should be considered to deliver carbon savings, cost savings and a healthy and comfortable environment.

Taking action on Climate Change

by Michelle Agha-Hossein, BSRIA Building Performance Lead

Most nations now recognise climate change as an established, perturbing fact that needs immediate attention. We can see the effects in the worsening and more frequent extremes of weather: flash floods, droughts, strong winds, heavy snow, heat waves, etc.

UK temperatures in 2019 were 1.1°C above the 1961-1990 long-term average and it was a particularly wet year across parts of central and northern England. Still fresh in the memory are storms Ciara and Dennis in February 2020 with strong winds and heavy rain that caused significant damage to homes and commercial buildings. There is growing evidence that periods of intensely strong winds and heavy rain are likely to increase in the future.

The UK is not the only country affected by climate change. Many other countries are (and will be) suffering disproportionately. The world’s leading climate scientists have warned that we might have just 12 years to keep global warming at a maximum of 1.5°C. After this point, the risk of extreme weather conditions will significantly increase. The increased frequency and intensity of extreme weather will affect all but is most likely to bring catastrophic consequences in many less economically developed countries, where food shortages and water scarcity can trigger deep social changes.

Immediate radical action is required to limit carbon emissions, and the built environment industry can play a crucial role by changing the prevailing culture.

Most building-related carbon emissions are generated from energy use in buildings. However, there are choices that building owners/operators can make and initiatives that they can undertake to lessen the related negative impact on the environment:

In brand new buildings, the most effective way for addressing emissions is reducing consumption through energy efficient design. In existing buildings, the issue can be addressed by efficient retrofitting and effective maintenance strategy. Adopting renewable energy technologies in both cases can significantly reduce building emissions.

Steps building owners and operators can take today.

There are several initiatives/activities that can help building owners/operators combat climate change:

  • Consider ‘net-zero carbon’ targets for your building: UKGBC launched its Advancing Net Zero programme in 2018 and published the ‘Net Zero Carbon Buildings: A Framework Definition’ in 2019. The framework provides the construction industry with clarity on the outcomes required for a net zero carbon building.
  • Ensure the required outcomes for a ‘net-zero carbon’ building are achieved: As advised by UKGBC in the framework definition, initiatives like BSRIA Soft Landings should be adopted in new build as well as in refurbishment projects to ensure a net zero carbon building will be achieved. The BSRIA Soft Landings framework provides a platform for project teams to understand the required outcomes for their project and ensure all decisions made during the project are based on meeting those outcomes.
  • Maintain your net zero carbon building effectively: Business-focused maintenance is a methodology developed by BSRIA that can be adopted to help building operators maintain critical assets effectively and efficiently to sustain a net zero carbon building within budget.
  • Investigate failure quickly: Is the energy bill for your building higher than it should be? Investigate the problem as soon as you can. The first and easiest step would be looking at the energy end use breakdown to see which areas are using more energy than expected. If the issue is related to the HVAC system, check the system’s setting points and monitor the indoor air temperature and relative humidity. Thermal imaging of the fabric of the building can also help to identify, thermal bridging, missing/damaged insulation and areas of excessive air leakage.
  • Promote a healthy diet among building occupants: This is a non-technical initiative that building owners/operators can adopt in their buildings. Eating less meat and gradually shifting to more plant-based foods is vital for keeping us and our planet healthy.  It is important to think about initiatives such as using signage or lunchtime talks, to educate building occupants about healthy diets and encourage them to eat more fruit and vegetables. Research has shown that adhering to health guidelines on meat consumption could cut global food-related emissions by nearly a third by 2050. Healthy diet is also supported by Fitwel and the WELL building standard.

Building owners and operators, to play their role in combating climate change, should ensure their decisions and the way they create and run their buildings contribute positively to the wellbeing of our planet and its citizens.

So, make a start today and choose the first thing you are going to assess/change in your building to help combat climate change.

To find out more about how BSRIA can help you improve building performance, visit us here.

A forward thinking attitude to energy management

Chris Monson, Strategic Marketing Manager of Trend

Chris Monson, Strategic Marketing Manager of Trend

Given that in parts of the world like Europe and North America some 40% of all energy used is consumed by buildings, both companies and wider society are increasingly focussing on the energy performance of their buildings, and how to improve it.

Building Energy Management Systems (or BEMS) are computer-based systems that help to manage, control and monitor building technical services (HVAC, lighting etc.) and the energy consumption of devices used by the building. They provide the information and the tools that building managers need both to understand the energy usage of their buildings and to control and improve their buildings’ energy performance. 

I’m Chris Monson, strategic marketing manager at Trend Control Systems, and I’d like to welcome you to the latest in a series of blogs where I, along with my colleagues, examine the issues affecting the building controls industry and the use of Building Energy Management Systems (BEMS).

It strikes me as somewhat bizarre that in an age where owners, managers and occupiers of commercial premises are under tremendous pressure to operate as energy efficiently as possible, so few developers recognise the long-term value of installing a fully featured BEMS at the construction stage. Such is the value and relevance of this technology, that to my mind it should be considered as important as other elements of the building services infrastructure that are designed in as a matter of course.

BEMS facilitate greater energy efficiency and the cost savings and the environmental benefits that can be experienced as a result of investment in this technology are considerable. A fully integrated solution can have up to 84 per cent of a building’s energy consuming devices directly under its control, offering greater visibility of energy use by monitoring services such as heating, ventilation, air conditioning (HVAC) and lighting.

According to the Carbon Trust 25 per cent of a building’s energy is used in lighting, and it is estimated that around a third of the energy consumed in this way in non-domestic buildings could be saved by utilising technology that automatically turns off lights when space is unoccupied. In addition, air conditioning can increase a building’s energy consumption and associated carbon emissions by up to 100 per cent, making it imperative that its use is tightly controlled.

So why isn’t the design and installation of a BEMS happening in the initial stages of a construction project? I’m afraid that the answer comes down to a combination of cost and lack of foresight. However, to fully understand why these two factors are proving so prohibitive to BEMS implementation, we need to understand a little more about the mind-set of the developer.

Developers tend to fall into two broad groups – there are those that configure buildings for others to inhabit and others who design and build premises for their own use.

When it comes to the former, the main driver is to save costs at the construction phase and little thought is given to the building’s future occupants and how they use the building. As there are no regulations stating that a BEMS must be installed, there’s a strong possibility that it won’t be. However, this lack of forward thinking leads to future occupants having to cope with inadequate visibility and control of their energy usage and, therefore, higher overheads and a larger carbon footprint.

Regarding the second group, it often comes down to the failure of owners to specify the need for a BEMS at procurement stage and make sure that they have systems in place that will maximise the energy saving potential of the building. While this type of developer will also have one eye on the cost of the project, the increased capital costs of installing BEMS is easily countered by the return on investment (ROI), with an average payback of just three and a half years.

Whichever way you look at it, the fact is that on a ROI basis early stage BEMS implementation makes sound economic sense. It can form less than one per cent of the total construction expenditure and energy savings of 10-20 per cent can be achieved when compared to controlling each aspect of a building’s infrastructure separately. The benefits don’t stop there either, as if it is incorporated with smart metering, tariff changes can be used to offer a strategic approach to energy management and control, and the data produced gives clear signposts for potential improvements.

I firmly believe that in the current business climate to construct a new build property without a comprehensive BEMS borders on foolhardiness. Organisations are faced with growing pressure to demonstrate carbon reduction policies and do all they can to lower their energy use.

Despite the controversy surrounding the introduction of the CRC Energy Efficiency Scheme, it is here to stay and is likely to extend its scope to incorporate more businesses in the future. In addition, The Climate Change Levy (CCL), Display Energy Certificates (DECs) and Energy Performance Certificates (EPCs) also affect businesses, while compliance with certification standards such as ISO 50001 put the onus on companies to demonstrate continual improvement in this area.

It should also be remembered that building occupiers are demanding greater visibility and transparency of their energy consumption and need access to data. A failure to meet this demand could mean that prospective tenants decide to go elsewhere.

Standardisation is playing an ever more prominent role and the most significant is EN 15232, which describes methods for evaluating the influence of building automation and technical building management on the energy consumption of buildings. It enables building owners and energy users to assess the present degree of efficiency of a BEMS and provides a good overview of the benefits to be expected from a control system upgrade. The use of efficiency factors means that the expected profitability of an investment can be accurately calculated and I’m pleased that a growing number of organisations are reviewing this document and implementing some of the best practice guidance it offers.

There are those who feel that regulation is the only way to make sure that BEMS are installed at the point of initial construction, although others are reluctant to see the introduction of more onerous legislation on an already pressured construction sector. At this stage I think that regulation shouldn’t be necessary if a long-term approach to energy efficiency is factored in and the benefits of a BEMS are recognised by more developers in the initial stages of a project.

Trend_RGB SMALLFor further information please call Trend Marketing on 01403 211888 or email marketing@trendcontrols.com. Trend are the main sponsors of this year’s BSRIA Briefing – Smarter ways to better buildings.

You can read more BSRIA blogs about BEMS here.  BSRIA’s WMI team also produce a BEMS market report – Building Energy Management Systems (BEMS) in Europe and the USA – which is available to buy from the BSRIA website. 

Best & Worst Practices Please!

Julia Evans, BSRIA Chief Executive

Julia Evans, BSRIA Chief Executive

BSRIA recently held a workshop on behalf of DECC identifying priorities to promote low carbon heating and cooling in non-domestic buildings as part of the development of its low carbon heat strategy.  Attendees were drawn from both the Young Engineers and Energy and Sustainability BSRIA networks.  Personal thanks to AECOM’s Ant Wilson for chairing the event.

It was a busy day.  It recognised that both new and existing buildings have a pivotal role in reducing greenhouse gas emissions, and by 2050 one of the key requirements will continue to be how we provide heating and cooling.

BSRIA’s Peter Tse and Ian Orme both gave excellent presentations which drew on both good and poor practices identified from more than 50 independently assessed case studies.  These, I felt, answered the questions “what does good practice look like”, as well as “what are the consequences when its not followed”.

The workshop session resulted in many suggestions as to priorities for the future.  There were a couple which caught my eye.

In response to the suggestion that one of the priorities for DECC should be identifying independently assessed best practice and developing exemplars of new technologies, a number of delegates felt that instances of “bad practice” were even more helpful.  It seemed to me that a priority for at least a part of the audience was to know what to avoid doing.  Perhaps this reflects the industry’s receptiveness to messages about risk, and that we often learn most when we make mistakes.  The emphasis on “independent assessment” also resonated.  Many have become sceptical about instances of self-identified “best practice”, and BSRIA’s independent guidance on what works, and what does not, is there to assist the industry do things better.

Another of the workshop themes was on “skills shortages”.  After many years of recession, construction companies have euphemistically “right sized”, and this means that we have lost a lot of great talent from the industry.  Now that there are green shoots of recovery in construction, there is already talk of an exacerbated “skills gap”.  This gap makes it even more challenging for the industry to deliver buildings which meet the needs of their occupiers and where innovation is required to help tackle climate change, and meet the UK’s commitment to “zero carbon” and “very low energy” buildings. This reminded me of another of BSRIA’s strengths – training provision.

BSRIA's 2014/15 Training Brochure

BSRIA’s 2014/15 Training Brochure

Finally there was an astute observation that our recent quest for low carbon buildings has meant that we have worried less about the efficient use of energy, with the net outcome that we can end up with an EPC A rating for carbon design, but a DEC G rating for energy in use.  The move to policies that move us to buildings which are both zero carbon and nearly zero energy use will hopefully remedy this, although I suspect this particular journey may contain further unintended consequences before we reach that goal.

The workshop identified many requirements if we are to create environmentally conscious buildings that meet user needs, and importantly maintain these elements over the life of the building.

BSRIA’s mission remains to “make buildings better”.  As part of my role, I’m listening to our members and the industry what they expect from BSRIA.  I’d like to extend this offer to you, so if you have ideas about BSRIA’s future role, please send them to me: Julia.evans@bsria.co.uk.

To learn more about the BSRIA workshop you can download all the presentations from our website. 

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