Welcome to part three of our four-part series on the impact that poor IAQ has on occupant wellbeing. This time we discuss measuring what really matters, and how to utilise data to make a positive change.
Measuring what matters
The most influential parameters we can measure are those that relate to comfort and health.
The basic measures of comfort are Dry Bulb Temperature (air temperature) and relative humidity. In a typical air-conditioned building, temperature measurements are only ever correct at the point of measurement, and relative humidity is invariably low and uncontrolled. Drafts and air movement also impact comfort and are almost never measured.
More useful to measure is Mean Radiant Temperature, which considers the surface temperatures of our surroundings, such as cold glass or floors warmed by direct sunlight. This is what our bodies really feel and has a more significant impact on comfort. Daylighting is also important — natural light is important for our general feelings of wellbeing and meets our biophilic drive to be connected to nature.
Out of these measures, Dry Bulb Temperature is the only one consistently measured and regulated. Relative humidity is usually only measured when specific needs demand it, such as in a data centre. Drafts and Mean Radiant Temperature are almost never measured in the field, and daylighting is rarely measured unless intelligent lighting controls are installed. To truly measure comfort, we need to take all of these indicators into account.
When it comes to measuring health, monitoring CO2 levels is an easy way to improve IAQ. By aiming for a target maximum of around 800 PPM (depending on the situational ambient CO2 levels), it’s possible to minimise the impairments to productivity and learning ability in workplaces and schools.
There are other, less obvious measurements that should also be considered. Total Volatile Organic Compounds (TVOC) are emitted as gases from common building products and, at increased levels, can have a negative impact on occupant health. If a building has interior car parking, carbon monoxide levels should also be monitored as high levels can cause fatigue, headaches, confusion, and dizziness.
Natural occurring particles such as pollen, droplets, mould spores and pathogens can cause health issues and can be tested for with air and surface swabbing. An unusual but increasingly recognised risk in some counties is radon, a radioactive gas that is a major cause of lung cancer. It results from the breakdown of naturally occurring traces of uranium in the ground and can accumulate in basements. Fortunately, New Zealand does not have this issue.
Of all of these, only carbon monoxide measuring is mandated. CO2 is now commonly measured in most new buildings, but monitoring is rarely retrofitted into existing buildings. TVOC’s are sometimes monitored instead of CO2 but it’s rare for both to be monitored together. And monitoring of natural particulates, or air and surface swabbing are almost unheard of in New Zealand.
How to make use of the data
A lack of measurements and reporting is contributing to poor results in terms of comfort, health, and wellbeing within our buildings. But if the goal is great IAQ, so we can have healthier buildings and occupants, measurement alone is not enough. There needs to be real-time system adjustments or operational procedural changes in response to the data that has been gathered. To get meaningful engagement from stakeholders, changes need visibility. For example, a dashboard that tracks monitored results and shows progress towards a building’s ideal targets gives everyone usable information and motivation to make positive changes.
A white paper on the entire four-part series can be downloaded here.