The Greenhouse Gases in your Office
The issue of global warming has rightly made reports about greenhouse gases into an international news staple. But there’s another reason for property businesses to pay attention to carbon dioxide levels — IAQ, or indoor air quality.
Most of us prefer today’s offices with their double and triple glazing, full insulation and on-site HVAC systems (heating, ventilation and air-conditioning) to the draughty, centrally heated workspaces of the last century. Unfortunately, that control comes at a price.
The human body evolved in the open, and our respiratory functions reach peak performance in the outside air (known as ‘OSA’ to atmosphere researchers).
If you gather us by tens or hundreds into enclosed spaces with tightly-controlled ventilation, that performance may start to suffer.
Air is complicated stuff, and yet there’s little consensus on the exact health impact of compromised IAQ. But at least we seem to be reaching agreement on an appropriate metric for discussions of air quality – CO2 concentration.
Although we know atmospheric CO2 is on the rise, OSA samples from sites across the world still show concentrations of only some 400 parts per million. That’s a minute fraction.
A sample of your exhaled breath contains a much higher proportion of the gas – around 40,000 ppm, in fact.
That hundred-fold increase will impact directly on the air around you. Under poorly ventilated conditions, human activity can result in substantial local build-ups of carbon dioxide.
Exposure to those elevated CO2 concentrations is known to be detrimental to us.
Recognised symptoms include drowsiness, emotional upsets and fatigue. Higher doses produce more extreme and less familiar responses, but many of us will already have experienced the pervasive, hangover-like symptoms of low-level exposure.
Exactly how much CO2 is too much?
Standards for IAQ seem to be getting more stringent as research comes in.
Accepted safe working limits for industrial environments allow for CO2 concentrations up to 5,000 ppm, twelve times higher than that of fresh air.
But more recent guidance from the influential ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) stipulates a much more modest 1,030 ppm as a normal limit – just three times the atmospheric level.
Modern sensors are more than capable of dealing with such subtleties.
The units we supply at ZiggyTec take accurate half-hourly CO2 readings and relay them to the Cloud year after year using inbuilt IoT (Internet of Things) networking. As they’re low-cost, battery-powered devices, we can easily monitor IAQ at multiple points throughout a building or an entire property portfolio at a fraction of the cost of existing solutions.
Some clients are leveraging their investments by integrating ZiggyTec sensors with existing HVAC systems. The result is a DCV (Demand Controlled Ventilation) solution which triggers a fresh air ‘purge’ whenever CO2 levels pass a threshold.
Bearing in mind that our health-conscious public is now equipped with ubiquitous electronic measuring devices, we believe that landlords and property managers would be well-advised to add CO2 monitoring to their buildings management system strategies moving forward.