VAC to full health
Expended air is a human waste product so why do modern buildings make it so hard to replace with healthy fresh air from outside?
A new report from Professor Hazim Awbi at Reading University has highlighted the potentially devastating impact of poor indoor air-quality in more energy efficient homes and the story has been picked up by the national media.
Professor Hazim Awbi has been quoted as claiming that “poor indoor air quality is connected with a range of undesirable health effects, such as allergic and asthma symptoms, lung cancer, chronic obstructive pulmonary disease, airborne respiratory infections and cardiovascular disease”. The finger is pointed firmly at modern construction techniques but just how have we got here and what is the route out?
Air-leakage = energy leakage
Every m³ of air heated requires an input of energy and every m³ of air lost through the building fabric is energy that has literally gone out of the window. With walls and roofs all insulated to modern standards, air-leakage actually represents the biggest single route through which energy is lost from a building.
This is why the most modern and energy efficient buildings are designed to be air-tight.
It’s a far cry from the way that buildings were historically designed. The traditional approach was always to allow lots of air-circulation to replace the unhealthy smoke filled air with fresh air from outside.
Today’s indoor pollutants, Carbon dioxide, Formaldehyde and Volatile Organic Chemicals (VOCs), may be far less visible (in many cases they’re completely invisible and odourless) but they all contribute towards poor indoor air quality and they’re all trapped in the building by the desire to eliminate energy loss.
Ventilate – don’t hyperventilate
The solution to the indoor air quality problem is not to reverse the gains that structural insulation and air-tight buildings have brought. Zero Carbon buildings are essential for the future sustainability of our society and impossible without high levels of insulation and air-tightness.
Mechanical ventilation and air-conditioning systems to replace the polluted air are a big part of the solution.
Whilst it might seem counter-intuitive, ventilation and air-conditioning can be implemented without compromising the energy efficiency of a building. Provided the system is appropriately designed and well insulated the system will not create a thermal bridge in the building fabric.
Insulation for healthier environments
Of course one of the best ways to ensure a healthier indoor environment is not to introduce any unnecessary pollutants in the first place.
One of the headline figures of the recent report from the University of Reading is that, if current trends are maintained, VOC concentrations within buildings will be up to 60% above world health organisation (WHO) 24 hour limits by 2050. All construction materials have the potential to contribute towards these VOC limits but some materials are much lower in VOC content than others.
Kaiflex insulation is specifically designed to exhibit low VOC content and is free from Formaldehyde, one of the most common VOCs. Equally importantly, Kaiflex is highly efficient thermal insulation that retains its thermal performance over long periods of time so modern Zero-Carbon buildings can utilise Kaiflex without impacting on their energy saving performance.