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Maintenance and Optimisation of Ventilation Systems in the Passivhaus

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Maintenance and Optimisation of Ventilation Systems in the Passivhaus

By Ruth MacEachern

Product Manager

Mar 13, 2024

To meet the high air quality and energy efficiency standards required for a building to be Passivhaus certified, regular maintenance of the ventilation system is essential.

The building not only has to be compliant with the regulations when undergoing the initial design of an energy-efficient ventilation system, but on an ongoing basis. These regulations are set by the International Passive House Association, with the UK affiliate being the Passivhaus Trust.

The importance of regular maintenance

In addition to compliance with Passivhaus Trust standards, regular maintenance ensures the overall energy efficiency of the building. This energy saving is one of the key objectives architects consider when looking at how to build a Passivhaus certified property, in order to meet government targets to reduce carbon emissions.

Optimisation and maintenance also ensure the system runs cost-effectively and more efficiently than a traditional heating and cooling system.

Other benefits of regular maintenance include:

Maximum performance - regular maintenance ensures that the system operates at its optimal performance levels, effectively ventilating the indoor space while recovering heat energy from outgoing air.

Energy efficiency - a well-maintained ventilation system contributes to overall energy efficiency by ensuring that the equipment functions effectively, reducing the need for additional heating or cooling.

Extension of equipment life - routine maintenance helps extend the lifespan of ventilation system components, such as fans, motors, and heat exchangers. By addressing minor issues promptly and conducting regular inspections, maintenance can prevent major breakdowns and costly repairs, ultimately prolonging the lifespan of the equipment.

Prevention of contamination - Over time, dust, debris, and pollutants can accumulate in the ventilation system’s filters, ducts and heat exchangers. Regular maintenance, such as filter replacement and cleaning, helps prevent the buildup of contaminants that can compromise indoor air quality and system efficiency.

Occupant comfort and health - regular maintenance of ventilation systems help prevent issues such as stale air, moisture build-up, and indoor pollutants, to benefit occupant comfort and health and therefore productivity.

Good to know

Residential Passivhaus ventilation is based on energy-efficiency and user comfort through the use of MVHR. This involves the extraction of stale, moist and humid air from wet rooms through a heat cell which is able to retain any heat in the air being expelled. Fresh, filtered air is then supplied into the habitable areas of the property with the added benefit of the retained heat. This differs from traditional mechanical ventilation which results in heat loss as well as the removal of stale, moist air.

Routine maintenance for Passivhaus ventilation systems

To ensure the Passivhaus ventilation system consistently delivers results that meet Passivhaus Trust standards there are certain key maintenance tasks that should be performed regularly. These include:

Filter inspection and replacement – the most important of all maintenance tasks which should be carried out every 3-6 months, depending on where the property is located, occupancy and living habits. Filters help remove dust, pollen, and other airborne particles, ensuring clean indoor air and preventing the buildup of contaminants within the ventilation system.

Cleaning air ducts and components – the periodic inspection and cleaning of air ducts, grilles, and diffusers. This helps maintain proper airflow distribution and prevents blockages that can hinder the ventilation system’s performance.

Inspecting insulation and seals – to ensure they are intact and there are no gaps or leaks that could compromise the airtightness of the Passivhaus concept.

The above are all easy to do yourself if you follow the instructions. In addition, professional inspection and servicing should be carried out routinely by qualified and competent persons and specialists familiar with Passivhaus ventilation systems (contact the Passivhaus Trust for more information).

In addition to the checks you can carry out yourself, professional servicing will monitor airflow and humidity and replace any faulty parts. It will ensure that all components are functioning correctly and helps identify potential issues before they become a major problem.

A service engineer can also review system performance data to identify trends,  anomalies, or areas for improvement in ventilation system performance.

Common problems

Undertaking the above simple maintenance of Passivhaus ventilation systems can avoid some of the common problems that can lead to inefficiency and long-term issues.

These could be:

  • Filter blockage
  • Imbalanced airflows leading to blank spots and potentially localised mould.
  • Heat exchanger breakdown
  • Excessive moisture buildup leading to mould growth and condensation
  • Air leakage compromising the airtightness of the Passivhaus
  • Excessive noise or vibration from fans or motors
  • Breakdowns or errors in the ventilation control system resulting in improper operation
  • Inadequate fresh air supply delivering poor indoor air quality

Regular maintenance and servicing are essential to prevent and address common problems with Passivhaus ventilation systems. Neglecting maintenance and inspection of the ventilation system can result in the accumulation of problems over time, leading to decreased performance, increased energy consumption, and potential health hazards for occupants.

Mechanical ventilation is considered to be a key component of the homes of the future. As the world plans to combat greenhouse gases and reduce emissions, sustainable housing and building to the Passivhaus Standard will continue to be an eco-friendly solution to modern living.

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