WHOLE-BUILDING HVAC APPROACH NEEDED FOR GOOD ENERGY EFFICIENCY AND IAQ
Martin Passingham, Product Manager at Daikin, explains how taking a whole-building approach to HVAC is intrinsic to improving indoor air quality and energy efficiency, and why this is an important consideration for installers.
It is ever more important for the environments that we live and work in to be as healthy as possible. With increasing requirements for airtightness, and the fact that we typically spend around 90% of our time indoors, there is a pressing need for a renewed focus on indoor air quality.
Pollution from traffic, construction activity, and pollen can be drawn into a building from outside through natural or mechanical ventilation and via infiltration through the building’s fabric. Similarly, dust, damp, and mould are some of the main sources of internal pollution, alongside emissions from office equipment and Volatile Organic Compounds (VOCs) emitted by wall and floor coverings, furniture, and appliances.
Add the emissions produced by building occupants (carbon dioxide, colds, viruses, etc.) into the mix, and it is clear why improving indoor air quality is such a hot topic.
A healthy internal environment is vital for our mental and physical health. Heating and humidity levels, adequate ventilation, lighting, and cleanliness all play a key part, so ensuring that all of these factors are considered, along with a suitable way of controlling them, is imperative.
Installers are increasingly being called upon to carry out costly remedial works to building systems in order to achieve this aim. This can lead to significant capital outlay for building owners and potentially higher running costs too, which make for an unhappy client.
Taking a whole-building approach to HVAC is fundamental. This means striking a balance between optimum indoor air quality and energy efficiency.
How can this be achieved? By installing the most efficient HVAC systems possible that effectively control comfort in the indoor environment, while providing an adequate supply of fresh air.
In the past, simply opening a window would have been the first port of call to bring in fresh air. However, in cold weather and in densely populated areas with high levels of pollution, this may not always be an option. An effective ventilation system is therefore paramount, one that must meet the requirements of building occupants by providing sufficient fresh air supply, and extraction of pollution and moisture build-up.
System design, installation, filtration, and maintenance are all integral to an effective and energy efficient system. There are a number of British Standards applying to these key areas that must be adhered to.
Once the basics of good system design have been achieved, additional pieces of technology can be added on to further enhance performance and air quality, such as ionisation systems that neutralise airborne pathogens like bacteria, viruses, moulds, odorous gases, and VOCs. It is a fit-and-forget solution with no additional maintenance requirements, and does not impede ventilation system performance and airflow, or use additional energy.
However, it must be emphasised that improving indoor air quality should always be a holistic approach, taking into account the correct specification, installation, and maintenance of core building systems first.
In essence, the benefits of creating healthy and efficient buildings are symbiotic – building users benefit from a healthier internal environment to live and work in; owners benefit from a cost effective, high performance building that is easy to maintain; and the environment benefits from less carbon emissions and pollution, which is better for everyone involved.