Ruth MacEachern, product manager at EnviroVent, discusses the importance of implementing energy-efficient ventilation solutions in modern builds.
“Updates to Approved Document L of Building Regulations has reinforced the need for greater airtightness in new homes and renovations. However, airtightness must go hand-in-hand with effective ventilation to ensure good indoor air quality levels are maintained in the home. However, to be part of a sustainable build, ventilation systems must have been chosen not only for their capacity to improve indoor air quality, but also for their energy-saving capabilities.
Whilst airtight construction prevents heat from escaping, there could potentially be issues with condensation and mould growth if not properly managed, making the selection of appropriate ventilation systems crucial for maintaining healthy indoor environments.
How ventilation enhances energy efficiency
An effective ventilation system can help to reduce energy consumption by optimising airflow, therefore lowering the demand for heating and cooling, which can in turn lead to reduced energy bills.
When selecting ventilation solutions for construction or renovation projects, a number of different systems are available, each offering distinct advantages for different applications.
Mechanical Ventilation with Heat Recovery (MVHR)
MVHR systems, including the energiSava and Slimline ranges, provide whole-house ventilation by continuously removing stale, moisture-laden air from wet areas whilst delivering fresh, filtered air to living spaces. These units incorporate heat exchangers that recover substantial heat (achieving up to 93% thermal efficiency in certain models), which significantly enhances energy performance.
When implementing energy-efficient ventilation systems, a project must ensure compliance with Approved Document O of the Building Regulations, which addresses overheating mitigation in residential properties.
It is therefore advisable to select MVHR units featuring automated summer bypass functionality, which channels air around the heat cell during warmer weather, preventing overheating and helping to stay compliant with Approved Document O requirements.
Mechanical Extract Ventilation (MEV)
MEV systems are engineered to extract air from specific household areas, particularly kitchens and bathrooms, where moisture levels are highest. These can be installed as either centralised or decentralised units, depending on property configuration. MEV systems incorporate variable fan speeds, enabling customisation, based on occupancy patterns or room utilisation. Particularly well suited to smaller, more compact properties, MEV systems deliver notably reduced energy consumption compared to conventional alternatives.
Positive Input Ventilation (PIV)
Positive Input Ventilation (PIV) systems establish optimal living conditions by delivering a steady stream of clean, filtered air throughout a property. As a widely adopted whole-house ventilation solution, these systems function by drawing fresh air from the exterior environment through specialised filters. Installation options include both loft spaces and wall-mounted configurations for flats and apartments. Their primary function is to maintain a consistent air supply within the home, effectively eliminating or substantially reducing condensation issues.
These systems are extremely energy efficient as they utilise low-power fan technology to sustain airflow. Many contemporary PIV units are specifically engineered to align with energy performance criteria making this ventilation solution a great option in properties.
Performance and compliance
Choosing the right energy-efficient ventilation system requires a thorough assessment to guarantee both optimal functionality and adherence to Building Regulations.
The initial consideration must be the building’s architectural design and spatial arrangement, as these fundamentally influence ventilation system selection. Critical factors include property size, room configuration, solar shading, choice of building materials and the location of rooms with additional humidity. This assessment becomes particularly vital for Approved Document O compliance, as factors can significantly impact temperature regulation and occupant comfort if not properly considered during the planning stages. Inadequate planning may result in additional expenses and modifications later in the project timeline.
All ventilation installations must demonstrate compliance with the current version of Approved Document F for ventilation provision.
From a financial perspective, the initial investment in high quality energy-efficient systems can introduce substantial long-term savings, particularly when you take into account ongoing maintenance requirements and energy usage. It is advisable to thoroughly review manufacturer warranties and support service agreements before committing to a ventilation system.
In addition, properties which feature energy-efficient technologies, including sophisticated low-carbon ventilation systems, often command higher market appeal among prospective buyers.
Energy efficient ventilation systems
The strategic selection of energy-efficient ventilation solutions for residential properties carries significant importance.
The latest updates to Approved Document F have increasingly stringent requirements for whole-house ventilation rates and enhanced airtightness in new construction to minimise carbon emissions. As a result, conventional ventilation methods, such as natural ventilation utilising intermittent fans and trickle vents, are no longer sufficient to achieve regulatory compliance.
Achievement of these standards requires a comprehensive ‘systems approach’ to ventilation, ensuring continuous fresh air circulation and effective pollutant removal to maintain superior indoor air quality. This can be effectively accomplished through whole-house ventilation solutions, including MVHR (Mechanical Ventilation with Heat Recovery), MEV (Mechanical Extract Ventilation), d-MEV (Decentralised Mechanical Extract Ventilation) and Positive Input Ventilation (PIV).
Collaboration at an early stage between building designers and ventilation manufacturers can bring positive benefits to a project in terms of enhanced energy efficiency, superior indoor air quality and the development of sustainable, low-carbon residential solutions for the future.”