Nicola Rivers at Zehnder Group UK explains why it’s important to consider ventilation when upgrading the fabric of homes.
Over the past few years, the UK’s plan for moving towards Net Zero buildings has taken shape. It will take time, but gas boilers are on the way out, with heat pumps slowly becoming the go-to solution for low-carbon heating. By 2035, the UK aims to phase out new natural gas boilers entirely.
The government, rightly, has lofty ambitions for decarbonisation. Its aim is to replace fossil fuel heating with electric heat pumps, setting a target of 19 million installations by 2050.
The case for doing it is compelling. Heat pumps already offer a carbon reduction of around 55-65% compared to natural gas boilers, and as the electricity grid continues to decarbonise, this figure could exceed 90%.
On top of this, there are new guidelines like the UK Net Zero Carbon Buildings Standard, which was recently released. It provides a methodology for construction and property professionals to prove how their assets align with the Net Zero targets outlined by the government.
Benchmarks like these are useful – both on the build side and the management side. Products will need to make greater use of Environmental Product Declarations (EPDs) so that facilities managers (FMs), building owners and property developers are able to clearly demonstrate how they contribute to a building’s overall environmental impact.
On the surface, this is all positive – having a solid plan in place is good. It means we are moving in the right direction.
But a major component of this plan requires buildings to be more tightly insulated to keep heat inside, which reduces natural airflow that brings clean air into our indoor spaces. While this is good for energy efficiency, it has a detrimental effect on the air we breathe inside our buildings.
And amid the laser focus on decarbonisation targets, energy efficiency, and installation targets for heat pumps, the one essential aspect of building systems being largely overlooked is ventilation. Currently, we’re on a pathway to low-carbon heating that will inevitably lead to buildings that can’t breathe in the way they should be able to.
We’ve already seen plenty of examples of government-sponsored insulation schemes, that though well-intentioned, have played a role in causing the worst possible consequences of poor ventilation: condensation, mould, and even in some cases, related respiratory issues and death.
Avoiding problems like these doesn’t mean we have to start from scratch. Energy efficiency and low-carbon heating solutions are things we should be continuing to strive for, but we need ventilation systems that work in tandem.
Simply put, it is not possible for conditions within our indoor spaces to be safe and healthy without effective ventilation systems. And you have to question the value of a low-carbon building that negatively impacts our health and wellbeing.
As with most systems however, it doesn’t have to be a choice between the two. Building truly modern and future-proof homes is about bringing the two elements of energy-efficiency and ventilation together to work in harmony. We know this is possible – it’s a case of shifting focus to include a ventilation strategy in our long-term vision for making our buildings better.
A system like Mechanical Ventilation with Heat Recovery (MVHR) is one way to drastically improve indoor air quality in a well-insulated building. The system works by pulling stale, damp and unhealthy air out of indoor environments and meticulously filtering the air that it draws in to provide a steady flow of fresh air inside. In this way, it works as the lungs of a building.
But they also help to make our buildings more energy efficient – and this is where these systems work in perfect harmony with the government’s ambitions for low-carbon buildings. The heat recovery component recovers the heat already in the stale air it draws in. It then uses that recovered heat to warm the supply air back into the building. This means that the heating system doesn’t start from scratch every time when it comes to heating the building, therefore saving energy that would otherwise be used from the radiators performance load.
MVHR is a shining example of how innovative, forward-thinking technology can enable low-carbon goals alongside effective ventilation. Achieving this harmony takes a systems-based mindset – where all the component parts of the technology within a building, from heating to ventilation and everything in-between, are designed and installed to work together, not in conflict with each other.
The phrase “insulate tight, ventilate right” has never been more relevant than it is today. We know that the decarbonisation of UK buildings is both necessary and overdue. Moving away from fossil fuel heating, improving energy efficiency and embracing new technologies are all positive steps.
But we cannot confuse carbon metrics with overall building quality or sacrifice one for the other.
A truly future-ready building is not just one that emits less carbon. It is one that uses energy wisely, making use of innovative solutions like MVHR to maintain healthy indoor conditions and enhanced energy-efficiency for the people who occupy it.
We are so close to getting it right. But to get there, we have to go beyond the goal of net zero buildings and strive to build better buildings in every way. Buildings that are not only energy-efficient, but also comfortable and healthy by design.
That is the direction the UK needs to move in – and it won’t be possible without fresh air thinking.
