Want to know what’s really going on in your building? Adam Garnys from CETEC knows all about the chemicals and other nasties in your building, and although we’ve got some building health hazards pretty much under control, for things like air tightness, mould and bacteria there’s still a lot of room for improvement.
Following is an edited version of his presentation
To bring a scientific perspective to the question: what makes a good indoor environment, there’s a list of things to consider: temperature, CO2 (which is an indicator of ventilation), VOCs (including formaldehyde), dust, lighting levels and acoustics.
So what are the advantages of creating a good indoor environment?
Because we spend so much time indoors, there are productivity gains – staff costs of an organisation are many more times more than your energy bill – and you can get credit points for rating schemes.
So what we look at with commercial buildings are subclinical target limits. There are other target limits that are legislated, such as in a paint factory, but that’s not what we’re talking about.
There are a few things to look at, such as the VOC formaldehyde. There’s a default level for offices. But the WELL standard takes different approach because VOCs are a group of thousands and thousands of chemicals, and they look at a list of the most toxic and relevant, and each chemical has its own limit, with a higher limit for something like benzene, which is a carcinogenic and is in carpets and paints.
Mould and bacteria are definitely on the rise in terms of being tested – the main criteria is that these don’t exceed outside levels. In particular, a building airconditioning and ventilation system should be making the air better than outside. That is part of its job.
Sensors and other technology
There are lots of IoT, sensors and other small devices on the market and scattered across offices. They have a lot of benefits – you’re getting data over a long period of time and they can provide a year’s data at 50 different data points in a building.
It’s fantastic to have that data – not something that we’ve had before in our industry. We typically go to a building a couple of times a year to do spot measurements.
That’s the same for ratings as well. It means you know when VOCs or other CO2 are increasing in one area of the building. But the problems are because they are low cost, the sensors aren’t great, they move out of whack after a few months, and with massive amounts of data, someone needs to watch it and do something about it.
These sensors are also not used for any rating tool at the moment. WELL gives credits for having it. For NABERS IE it isn’t mandatory, but it helps. But it’s the future.
The other important thing is placement. These things have to be put in the right spot. And we do have a large portfolio including premium grade buildings looking at the BMS [building management systems] data and the general consensus across the industry is woeful.
BMS data is usually on platforms that are 10 or 20 years old. This means it’s very hard to extract, and you need to get a specialist in that technology to set it up. And then you get the data and usually no one does anything with it.
Air tightness – if it’s leaking, it’s leaking expensive conditioned air.
Something else that’s on the rise is air tightness testing. It’s now part of Green Star. What it involves is pressurising a building and seeing how much it leaks. This has been happening in the US and the UK for quite a long time now. Another word for it is blower door testing.
It’s first focus is leaks – if it’s leaking, it’s leaking expensive conditioned air. But it also has the benefits of reducing pollutants from outside and being able to balance a building properly so you don’t get hotspots or areas that can cause mould.
So the score or measure of that is the flow of air over the metre square of envelope. In Australia the average building is very leaky compared to the rest of the world.
Mould and bacteria are more common in low rise buidling
Mould happens in commercial buildings. It’s more common in low rise buildings. Essentially, where there’s water, it will form. Through the property boom the quality of construction has gone down a bit, which means water comes in from the top, or from the bottom and is rising, or poorly conditioned HVAC is causing condensation.
Plumbing is also important.
Mould is particularly expensive to remediate. You have to have negative air units and all sorts of things.
We’ve come a long way in terms of assessment of microbe. What we do now, because DNA testing is so cheap is, we get an air test and get a chart that shows the species profiles.
You can compare indoor and outdoor profiles, and see if they are different. Some of these species are pathogenic and some are perfectly fine. This means we can make a risk of assessment – it’s a great tool that we’re using a lot now.
Mould is tricky and so are microbes. It hasn’t been written into WELL, it was in NABERS IE for a while, but because it is quite difficult to compare one building to another and make a score or judgement it was taken out.
There’s a lot of good guidance, especially out of America. NASA and the World Health Organisation have their own guidelines. It’s becoming more and more topical.
In Australian there’s been taskforce on mould and microbes. But so far we deal with these issues on a case by case basis. We’re hoping for more clear guidance on this in Australia in the coming years.