Q and A: Steve Kritzler of Aeris Environmental

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aeris filter treatment being sprayed onto hvac filters

FM speaks with Steve Kritzler, technical director at Aeris Environmental and Novapharm Research, about his work with HVAC and his company’s role in keeping things running cleanly and efficiently.

Kritzler has a background in chemistry, and research and development programs. As technical director at Novapharm Research, he put together infection prevention systems for hospitals after exploring infection risk in hospitals, looking at hospital air-conditioning systems, and being “frankly shocked” with what he found. The decision was made to put together a system of products aimed at remediating microbial problems associated with HVAC, and the result was a company called Aeris.

Aeris takes the various technologies developed by Novapharm for hospitals and uses them worldwide in industrial and institutional sectors. Kritzler speaks with FM about HVAC and horror stories, maintenance and savings, and COVID-19.

FM: How does what you saw in hospitals all those years ago compare to what you see these days in commercial HVAC systems?


Steve KritzlerSteve Kritzler: What we saw in hospitals was concerning but, frankly, what we saw in shopping centres was truly scary. We saw massive fungal growth. Mould – because the HVAC infrastructure is always wet. You know, when you walk under a small air-conditioner, a little window rattler type thing, and you see water dripping from it? Well, in very large commercial systems, there’s not water dripping, there are massive amounts of water condensing out of the air that’s coming in from the outside. And all of these very wet surfaces in the HVAC infrastructure grow mould. We saw mould, I’m not exaggerating, inches thick in some of these HVAC systems.

What we developed, and what Aeris is presenting to the world, is a whole system of products that remediate HVAC systems. So not only do you get an improvement in indoor air quality, but by removing the biofilms and the other microbial growth factors in HVAC, we’re able to save about, in certain cases, up to 25 percent of the electricity being used in the HVAC system, just by remediating it and getting rid of the blockages in heat exchanges. And so there is a significant payback to the facility management that does the remediation. So there’s a payback in less than six months.

Simply by having the system run clearer and more efficiently…

Exactly. For example, as the biofilm blocks up the tiny gaps in the heat exchanges, the variable speed fans have to work way harder to push the air through these narrow channels. So, by getting rid of the biofilm, these fans, which are attached to huge motors – I’m talking about large commercial buildings – are working way less. Not working as hard, there are benefits all round. [For example], all of this condensed water has to go down to the stormwater, in collective metal pans. The metal pan has got a small outlet that lets the water run down to the wastewater system. Once there’s biofilm growing in these pans, it can block up the exit, and a huge amount of exit just spills over. We’ve seen water damage in commercial buildings in Sydney that cost more than $12 million to remediate. But we developed a small tablet that you can put into these water pans. The small tablet slowly dissolves, releases biocide and enzyme, which gets rid of the biofilm so you can’t block up the pan.

So if they just change the tablet once every three months, it’s huge mitigation – common sense things like that.

How safe and environmentally friendly are your products?

What we focus on is, first, it’s being used in HVAC systems, so I can’t think of an exception, but virtually everything complies with biodegradability regulations. I don’t say that everything is completely non-toxic, but the toxicity levels are negligible. Where there is need for PPE, we make it clear that people should wear gloves and such. But the technology is the same fundamental remediation technology as has been used in hospitals. So we’ve got treatments for surfaces, for example, after the HVAC system has been remediated, we’ve got product that you apply to the surfaces, and it’ll stop any microbial growth on those surfaces for 12 months. So they only have to do this on an annual cycle, and they’ve got this remediation and the reduction in power consumption.

The reason I ask is it’s being used to clean air filters in spaces where people breathe the air.

A good example is the heat exchange, because it’s a major piece of the HVAC infrastructure. Previously, if anyone cleaned these heat exchanges, they used alkali caustic. And the caustic got rid of the microbial growth by dissolving the surface of the metal and then the bacteria on the surface fell off. But, slowly but surely, that destroyed the infrastructure and destroyed the equipment. So we’ve used our technology in the cleaning of medical instruments, where we use neutral enzyme cleaners. They’re non-toxic, so there’s no risk to the operators that are cleaning the coils. Where they were using caustic, they’re now using the same sort of benign enzyme: they’re natural products, they’re biodegradable. They’re using the same enzymes, with examples that are used, in many cases, in laundries. And the water authorities love you because they add the enzymes themselves to sewage, to digest fat. That’s just an example. We’ve gone from dangerous alkaline detergents to neutral low-concentration enzyme detergents that are themselves natural and part of the natural environment. 

The other thing that has attracted interest recently: we found, when we were doing our studies, that the air-conditioning dust filters were one of the major problems with respect to indoor air quality. Because you get a lot of mould growth within the dust filters. And then the spores from this mould just go into the air through the channels and directly into the air space that people in the building are breathing. So we’ve developed a product that’s just sprayed onto the dust filter, that stops any growth. And it not only stops the growth, it keeps the filter operational for much longer than normal, because a lot of the blockage within the filter is due to this mould growth. Now, we’ve recently done data that this treatment also kills COVID. So we’ve got a filter treatment that won’t kill all the COVID, because if the COVID is too fine to get caught in the filter it can still pass through, but a lot of the COVID is in droplets from when people cough or sneeze, and those droplets are caught up by the filter, and the COVID-19 is killed by the filter treatment. But those filter treatments, again, they last the life of the filter. So it’s a ‘treat once and forget’. They just replace the dust filter, they just monitor the back pressure of it. 

Look, honestly, it’s straightforward. Professor Lidia Morawska clearly advocates that it’s common sense, and during the pandemic there should be more fresh air interchange. And the other thing that she and other experts around the world advocate is that while the pandemic is on, that buildings should do better filtration, [use] dust filters, and they’re suggesting the use of HEPA (high efficiency particulate air) filters.

Now, HEPA filters are a lot more expensive than the filters that [many FMs] are using at the moment, and because they’re finer filtration, they block up faster. A much more practical approach to it is, by all means, put in the HEPA filter, but also put in another normal filter, as they’re using at the moment, as a pre-filter for the HEPA filter, so that the pre-filter treated with our filter treatment will pull out all the larger bits, the larger dust particles and droplets, the pre-filter will kill the COVID and it’ll protect the HEPA filter from getting blocked up so quickly.

Should your products be used on HEPA filters?

No. So what happens in the HEPA filters, the pore size is .2 microns. And a micron is a millionth of a metre. So the holes in the HEPA filter are so small that if you sprayed anything onto it, it’d just block it up. The filter treatment should go onto the pre-filter and then the pre-filter will dramatically extend the life of the HEPA filter. So, the HEPA filter itself, it’s just a little bit prohibitive in price. But if we can double or triple the life of the HEPA filter, then I think it’s a very good and commercially viable alternative.

Speaking from your expertise, what does a good HVAC management strategy look like?

At the very least, they need to be doing a complete remediation of the HVAC infrastructure, at least annually. And that includes everything. It includes the plant room, it includes the coils, and it only really needs to be done properly annually. Frankly, the payback on it, they’re going to come out way ahead in their energy savings.

Unfortunately, there are not many companies that have looked at this area of business, or addressed the problem. But if they use the Aeris system (that’s the only one I know intimately), if they do that annually, they are going to get a payback within six months. So it’s actually going to be not only cost neutral, but they’re going to come out way ahead by just doing one complete remediation a year. 

And, frankly, imagine if all commercial buildings did that – Australia would meet its energy targets easily. Because HVAC is probably, well not probably, it is the single largest consumer of power in most commercial buildings. By just instituting a program that improves their indoor air quality, it’ll allow their infrastructure to last way longer and they’re also contributing to Australia’s greenhouse gas targets.


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