HVAC – The global, post-pandemic context 16 June 2021
By Cecilia Schutz
In an ideal world, policies on building energy efficiency would be seamlessly integrated with those on health and productivity. COVID-19 has forced governments and businesses to consider energy efficiency through the health lens.
One aspect of the built environment is now under intense scrutiny – ventilation.
Energy efficiency practitioners will know that tempering outside air can be expensive. It’s one of the chief reasons so many commercial buildings are recirculating air with conventional, refrigerated systems.
There was a lot of early conjecture about the role of ventilation in COVID-19. A recent article in The Australian1 summed it up well:
The first recorded “super-spreading event” of COVID was at a restaurant in Guangzhou, China. Medical experts were confused – there had been no close contact and medical lore had it that respiratory “droplets” couldn’t travel more than a couple of meters. Indeed, early advice by the WHO said that droplets would travel a short distance and land on a surface from which the next potential infection could take place, via touch. Surface disinfection and frequent hand washings were the order of the day.
In a bid to ‘crack the code’, researchers looked more closely at these super-spreads and noted that most had happened indoors, with large groups gathered in poorly ventilated spaces. Doctors already knew that really small particles (not droplets, but ‘aerosols’) could travel longer distances, but for some reason thought it only happened in controlled medical circumstances, like a ventilator in an intensive care unit.
This discrepancy cued the broader science profession (think physicists, atmospheric chemists, and mechanical engineers) to bring their perspectives to the table. Their shared evidence showed unequivocally that aerosols, in a respiratory context, could actually travel a long way, and not just in “medical settings”, as previously suggested.
One of these academics pulled together 36 experts in aerosols and air quality, who collectively put forward their evidence. More than 200 researchers from 32 countries signed over their support. The World Health Organization (WHO) updated its position but still fell drastically short of adequately recognizing the hazard of airborne transmission.
Despite this, many are acting on this scientific knowledge. The Massachusetts Institute of Technology has come up with a way to calculate the safe length of time to remain in a room with an infected person. In a typical American classroom, naturally ventilated, it’s 72 minutes. Add mechanical ventilation and it extends to 7.2 hours.
The University of Minnesota modelled the spread of aerosols in a classroom, accounting for natural and mechanical air movement and ventilation. They modelled the air-flow from the original Guangzhou super-spread and put the outbreak down to no source of external fresh air and a nearby recirculating air-conditioner.
Achieving efficiency in this new world
The above presents a challenge for building owners and an opportunity for energy efficiency practitioners. The demand for air-conditioning will continue to grow strongly, as will that for healthy buildings. But the cooling of outside air, particularly during an Australian summer, can be uneconomical for companies.
It isn’t difficult to achieve necessary ventilation measures, but many regulations and design standards are still chiefly concerned with objectives other than health – conserving comfortable inside temperature and reducing energy consumption. This means that the chosen avenue is often recirculating air rather than exchanging it with fresh air from the outside world.
However, the priorities of energy efficiency and building health will continue to converge at a rapid pace. For example, in Australia, there’s been a discussion of ‘ventilation certificates’ being issued for buildings, similarly to food-hygiene certificates which exist for restaurants. Energy demand from cooling makes up about 40% of a commercial building’s consumption. So, how will a big company, with big cooling requirements, achieve efficiency in this quickly evolving landscape?
Many companies target efficiency from a corporate social responsibility perspective, with a side bonus of financial savings. Arguably, energy efficient technology which is also able to deliver greater building health, less absenteeism, and greater overall productivity, is a very compelling proposition.
Indirect Evaporative Cooling and Climate Wizard
Indirect Evaporative Cooling (IEC) came about because a solution was needed to deliver fresh air into a building, without adding water to the supplied air. In traditional evaporative cooling, warm fresh air from outside is passed over water, which evaporates, cooling the air and adding moisture to it. While the added moisture can be highly desirable, especially in drier climates, it isn’t optimal for all applications. But traditional IEC still had significant limitations in achieving optimal cooling comfort with high efficiency.
Since our founding, Seeley International has put an incredible focus on both energy efficiency and research and development. Seeley is the first commercial manufacturer of ‘Climate Wizard Indirect Evaporative Cooling’ technology which combined the principles of IEC with a unique counter-flow heat exchanger. This development allowed IEC to get below the ambient wet bulb temperature and subsequently deliver supply temperatures (and efficiencies) that weren’t previously achievable. That technological advancement caused IEC to rapidly gain traction as it dramatically reduced the cost of injecting fresh air into a building. Climate Wizard is now installed in thousands of locations around the world, including in humid climates, and in a wide variety of building types.
Climate Wizard IEC can be used as a stand-alone cooling system or paired with standard refrigerated cooling systems to dramatically increase their energy efficiency. What makes Climate Wizard IEC cooling so exciting is its ability to deliver 100% outside air, with optimal comfort, at a fraction of the cost of refrigerated cooling.
The unique features of Climate Wizard are:
- Up to an 80% reduction in peak and overall cooling energy demand
- Optimal cooling comfort (16% C) with 100% outside air
- The refrigerant is natural and incredibly safe for the climate – “R-718”, otherwise known as water.
- 4000+ installations in 20+ countries, ISO9001 accredited quality, tested in the harshest climates
- 100% Australian owned, designed and made
Commercial Climate Wizard installations have a typical ROI of 3 – 5 years. While this accounts primarily for energy savings, it doesn’t consider the improved cooling performance and life of an existing refrigerated system, when Climate Wizard is used for a pre-cooling or supplementary cooling application. Even more critically, it doesn’t consider the improved comfort, health and productivity of a building that is well ventilated.
Seeley International is pleased to engage with all Energy Efficiency Council members to understand how we can contribute to your projects.
Cecilia Schutz is Manager Professional Relations and Global Advocacy for Seeley International and can be reached at +61 8 8328 3290/CSchutz@seeleyinternational.com. For more information about Seeley products, contact Michael Hamilton, GM Commercial Sales +61 416 222 460 / MHamilton@seeleyinternational.com
1 The Economist. 2 June 2021. ‘Improving ventilation will help curb Covid-19’. The Australian. https://www.theaustralian.com.au/nation/improving-ventilation-will-help-curb-covid19/news-story/d0465f8a77bb81dbf9f64291ef346fda