To switch on the heating, or not? – a surprisingly complex question

What is heat? - Dr Karolina Rucinska explores this topic in more depth through a series of articles the challenges and opportunities it poses for equality, decarbonisation and social transformation.

On cold, wet and windy days a bike ride to work seems impossible. Damp shoes and clothes seem too much to contend with and wrapping up in a blanket on a Zoom call seems too unprofessional. Whether in the office or at home, the temptation to reach for the electric heater grows as the gas prices are rising and central heating under-performs. “To switch on the heating, or not” is the question that many people across the Northern hemisphere are asking themselves.

Here at Cynnal Cymru we recognise these challenges as we too battle between the need for comfort and the feeling of warmth versus our knowledge about climate change. We know from the 6th Carbon budget by the UK Climate Change Committee (CCC), that direct building CO₂ emissions were 85 MtCO₂ in 2019, which account for 17% of total UK GHG emission. This was mostly from our homes (77%), followed by commercial buildings (14%) and public buildings (9%). The reason behind these figures is simple – it is our demand for hot water and heating. 74% of this demand in buildings is met by natural gas, and 10% by petroleum, with smaller amounts of other fuels such as coal and biomass.

To reduce total emissions, the ways in which we heat and use our buildings must be addressed. Recommendations from the CCC include changing behaviour (use less, lower the temperature), increasing building efficiency (insulation), and introducing low carbon heat (air source or ground heat pumps, hydrogen, low carbon district heating etc). The topic of heat then sits at the core of what we at Cynnal Cymru care about, not just professionally but personally too.

Over the last few months, we took part in an unintentional social experiment, because the building we are located in was undergoing a renovation of its central heating. We wore our thickest jumpers, we made many hot drinks, and despite all efforts, eventually, we turned to the electric heaters knowing perfectly well their economic and environmental cost.

This lack of heat got us talking about comfort, habits, energy, renewables, ways to keep warm, and insulation. We knew well that to reduce carbon emissions and to protect future generations, we need to do our bit around heat –which, in reality, may well mean getting used to feeling colder while waiting for a zero-carbon alternative to arrive. But how might this impact on those other fundamental human feelings and needs – for warmth, security and comfort? And what does this mean for the changes that we need to make as a society?

To delve deeper into these questions – and to explore the challenges and opportunities that Wales faces for warm homes and decarbonisation – Dr Karolina Rucinska, our Sustainability Advisor, set out on a research journey that will be shared over the coming weeks. We start with the basics – what is heat?

Heat is moving

If you are grumbling about how cold your house is despite having the radiators on, it is because heat, if it can escape, will always do so. However hard you try, the hot stuff will eventually become cold because the world we live in is governed by the uncompromising laws of thermodynamics. ‘Heat in motion’, Chris Woodford explains in Atoms under the floorboards (2016, Bloomsbury Publishing), ‘is another way to describe thermodynamics, which explains things like how cars waste energy, why power stations need such stupendous cooling towers, why cows have damp noses and dogs dangle out their tongues – and even why Arctic musk oxen spend so much time standing still in the snow.’

While the first law is concerned with energy loss, the second law of thermodynamics is concerned with the movement of heat, always from hot to cold and never the other way round. So, cold stuff is simply the lack of heat, while heat is stuff that always wants to go where there is less of it. Sounds weird, but effectively this is what is happening in our homes. Heat moves around and is, as it were, always on the go, so to make your home cosy, you are effectively trying to heat up every atom in everything that is inside. This takes huge effort and of course energy. If you are using different heaters that store heat and give it away at different rates, then you might wait hours if not days to feel cosy, while all that heat continues to slosh around and move.

This physical side of heat points to one thing: if you want to keep your house cosy, you must insulate it. Without insulation, heat will always escape regardless of how you warm it up. Before you look up low carbon alternatives to your boiler, invest in insulation.

If only it was that easy….

The UK has some of the oldest and most leaky housing stock in Europe. According to the Independent review on decarbonising Welsh homes, 32% of the Welsh housing stock was built before 1919, when there were no construction standards in terms of thermal performance. Research by the Cardiff University School of Architecture showed that the average energy performance (EPC) rating of the Welsh housing stock is a ‘D’ rating*, which raises the incidences of fuel poverty. 43% of people living in private rented accommodation are living in houses built before 1919.

The Guardian reports that, nine in 10 households rely on gas boilers, and lots of gas boilers need lots of gas: UK households consume more of it than almost all of their European peers, at around twice the EU average. With the price of gas going up and energy companies going down, heating leaky homes feels wasteful if they continue to be not insulated well enough to counter that physical side of heat. Between 2012 and 2019 the number of home insulation installations actually dropped by 95%. National Energy Action (NEA), the national fuel poverty charity, has noted that at that rate it would take nearly a century to properly insulate all of the current fuel-poor homes in the country. The statistics are eye-opening indeed. They are clearly telling policy makers and businesses that to significantly reduce carbon emissions from buildings by 2050, actions have to be taken now. But there is something about heat that speaks not to reason and data, but to feeling, an embodied feeling.

Heat is us

Like houses, our bodies too are governed by thermodynamics. Heat escapes our bodies and even after vigorous exercise, we eventually cool down. We give away heat, which we feel immediately, and we want to do something about it, immediately. But we cannot wait years and decades until housing stock is less leaky. We can put on the warmest jumpers to almost insulate our bodies as we would with our houses, but nothing will stop us from eventually feeling cold again. At some point we will need to, despite all that we know about the costs of gas and leaky houses, warm ourselves up. We are all taking temporary and readily available solutions simply because it is cold.

The problem though is that the embodied feeling is not experienced, which in turn perhaps influences our motivation and ability to act, for ourselves and others. Illness, age, cardiovascular system, place, and even norms, as research suggests, dictate how our bodies experience heat or lack thereof. If you have had a disagreement with your family or co-workers about the “right” temperature settings, then you will know what I am talking about.

Heat is suddenly a societal thing. It unites us as well as divides us. How one experiences heat or the lack of it, and what one does about it, also reveals something, unknowingly, about us. Which is why, heating our homes or not, it is about us too. It is a personal, deeply private and emotional thing. As researchers, Erin Roberts and Karen Henwood, from Cardiff University observed, heating is not just about thermal performance of a house, but about thermal comfort. It evokes the feeling of belonging, of feeling safe, of feeling looked after. It brings up the good memories of being with a family and sadly, bad memories of coming home after school with radiators off because parents, often despite being in work, cannot afford high energy bills. Heating can then become, unfairly, a social stigma and a social divide.

Heat is incredibly complex then, as it touches on our most intimate and most sacred parts of our lives, lives which, just like our housing stock, are governed by laws of thermodynamics. Our attention to these laws and insights, or lack of it, will influence future heating actions and policy.

Over the coming weeks, we will be sharing a series of articles to explore the challenges and opportunities it poses for equality, decarbonisation and social transformation.

*Properties are given an energy-efficiency grade between A and G, with A being the best – i.e., most energy-efficient – and G being the worst.

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