Put the focus back into teaching. A hybrid natural ventilation sustainable solution for our schools improves student learning outcomes by up to 20 per cent through improved indoor climate and inhabitant comfort while also reducing energy use by at least 40 per cent according to the Australian Greenhouse Office (2005); Brager, G.S. & De Dear, R. (2001); Buildings Energy Data Book (2008); The Natural Edge Project (2011); Nicol, J.F. & Humphreys, M.J. (2002), Origin Energy (2008); and Wargocki, P. (2010).
In the beginning there was a ‘raw’ climate out there. As humans became more affluent and buildings became larger air conditioning was invented to try to separate us from the outdoor climate and create an internal cocoon.
The majority of the population thought that these mechanical methods were the greatest and the most efficient invention of their generation for temperature regulation.
Now, as times change, with ongoing issues around poor indoor comfort and air quality, and the increase in knowledge regarding the value of a dynamic and ever changing indoor climate, the spreading of respiratory and influenza, drowsiness, irritability and poor learning outcomes for students, means that air conditioning, which was once known as the ‘saviour’, is now being seen as the cause of many of these problems.
In addition, if we also consider the massive energy running costs combined with the resultant carbon emissions and heat created by the air conditioning systems then the air conditioning equation starts to look poor.
Interestingly enough worldwide research across tens of thousands of respondents indicates that users of buildings are more comfortable in naturally ventilated or hybrid buildings (Brager & De Dear, 2001).
Schools are an institution for educating students. We need to provide the best indoor climate and environment to ensure that this learning can take place.
John Brodie from Vim Sustainability, a leading sustainability consultancy that specialises in education, says the numerous benefits of natural ventilation make it a practical and cost-effective method of creating a comfortable learning environment.
Natural ventilation could prove the most efficient and effective method of cooling classrooms in most areas of Australia. It could also provide measurable cost and performance benefits in ameliorating the issue of the unflued gas heaters and the related poor internal environment quality found in many schools.
It is time for a shift in thinking for those people that still remain stuck on the old ideas that mechanical conditioning systems are the only way to create comfort. What needs to be acknowledged now is the concept that either a full naturally ventilated building or a hybrid ventilation system is the way of the future in most climate locations.
The use of natural ventilation for cooling has been used for centuries in very hot dry and also and humid climates and advanced technology has now proved, once again, to hold a number of benefits over traditional mechanical cooling methods such as air conditioning. This holds true, especially for schools, where concentration and productivity levels are essential.
“Air-conditioning can contribute as much as 40 per cent of the energy use of a building and there are proven benefits to cooling buildings with fresh clean air such as reduced sick leave, increased concentration levels and learning outcomes” Brodie said as cited in Origin Energy’s Energy Efficiency Fact Sheet (2008) & Australian Greenhouse Office (2005).
Studies in Europe from the International Centre for Indoor Environment and Energy at the Technical University of Denmark in collaboration with WindowMaster (ICIEEDTU) have also found that a naturally ventilated school classroom will increase learning outcomes by one year over the school life time from years K-6. This is due to the children’s increased learning ability by up to 15 per cent with the provision of a good indoor climate (Wargocki, 2010).
“Imagine that our children could learn the same in seven years instead of eight years” Pawel Wargocki from ICIEE-DTU said.
“Natural ventilation is a highly efficient method of providing cooling and fresh air to large spaces including classrooms and w buildings and has already been successfully implemented in some innovative Australasian schools” Brodie said.
“As a cooling method natural ventilation and direct ventilative cooling can, dependent on climate and location, provide occupant comfort for up to 97 per cent of the year (as evidenced by the National Institute Science and Technology (NIST) Climate Suitability Tool in 2011) and it is low maintenance which delivers reduced energy costs with the added bonus of maintaining optimum oxygen levels creating a productive learning environment” Brodie says.
Brodie says “the key though with any natural ventilation system is the control strategy. If the control strategy is not suitable to the function of natural ventilation it is highly likely to not reach its required performance target and result in unhappy users’.
Natural ventilation systems that are automated and controlled, such as the NV Comfort™ system allows teachers to put the focus back into teaching instead of spending time manually opening and closing windows or using mechanical ventilation.
Denmark is leading the way in the use of renewable energy and is one of the most energy efficient countries in the world. They also lead the world in understanding and maximising the indoor climate. The Danish has recognised a vital mistake that many of us make in opening windows too late and closing them too early which significantly reduces the benefits that could be achieved via natural means.
WindowMaster® from Denmark has utilised 20 years of natural ventilation expertise in their NV Comfort™ control system which overcomes this timing problem and ensures the benefits of natural ventilation through an automated system which fits almost all types of windows while also providing full user control if required.
Their research and user surveys of what occupants require for thermal comfort and the implementation knowledge of over 2000 installations worldwide has gone into creating the unique NV Comfort™ control strategy and user friendliness of the touch screen.
The technology used in NV Comfort™ enables the façade and/or roof windows to automatically adjust silently by incremental amounts on the basis of individual fixed values for the desired room temperature, Relative Humidity and CO2 levels, as well as measurements of external temperature, rain and wind speed.
There is also a huge range of other programmability available around window performance and operational requirements, and security, etc.
Desired room settings are controlled by the NV Comfort™ touch screen that continually balances the internal climate with the outside climatic conditions. Other benefits of the NV Comfort™ system is its ability to work in conjunction with and control existing energy consuming climate control systems, if required, such as air conditioning, lighting, ceiling fans and gas heaters. This is particularly beneficial for those extremely hot or cold days when natural ventilation is not sufficient.
A hybrid system combines the best of natural and mechanical ventilation into a single solution, ensuring that the least amount of energy is used from these traditional sources to maintain the most effective internal climate conditions.
Vento Australasia tailored a highly intelligent natural ventilation system for a prototype classroom at a school at Pakenham, Victoria that was officially opened in the presence of Princess Mary on 24th November, 2011.
On the opening day, the classroom was filled with many attendees and they all commented on the high level of thermal comfort inside the building despite the warm external conditions.
This school used the NV comfort™ system in conjunction with the WindowMaster® actuators and SOLA-BOOST® solar assisted roof mounted natural ventilation systems. “Vento’s intent with this hybrid system was to provide maximum control and maintain ideal temperature and oxygen levels whilst minimising the use of mechanical air-conditioning and heating” said James Idle, Vento Australasia’s Senior Mechanical Engineer.
Idle is also heading the project at Westbourne Grammar School, again in Victoria which will follow a similar design to the school in Pakenham, but will include the controlling of light levels by using SUNPIPE® natural daylight systems and dimmable lights connected to a lux sensor as well as the ceiling fans. The NV ComfortTM system is in essence, at a much lower cost, replacing the Building Management System while providing unmatched natural ventilation control and occupant comfort.
Idle also explained ‘’through intelligent control and monitoring, both internal and external conditions are measured so that when natural ventilation is precluded the control system has the ability to tell the air-conditioning to turn on or off as required. However, the key to this function is that the air-conditioning has to be activated by the end user. This can potentially provide a dramatic reduction in energy-use, helping to minimise the operating cost and carbon footprint of the classroom.”
This smart control system acts independently allowing teachers to focus on teaching but is also designed to provide ease of use and user control as required.
These unique natural ventilation solutions have been installed across a range of schools across Australia and New Zealand.
Sustainability does not have one silver bullet but every little part helps. Implementing a hybrid natural ventilation system is one part of the sustainability equation that all schools should thoroughly consider. As previously stated, it definitely is the way of the future for climate solutions. A hybrid natural ventilation system provides many health benefits over traditional mechanical ventilation. It improves productivity, absenteeism and reduces illness caused by inhabiting a recycled air conditioned environment of constant temperature. Student concentration levels are significantly improved as well which is essential in a students learning environment.
In an assessment on Returns on Investment recently carried out by a Sydney engineering company for a hybrid naturally ventilated school in Sydney using the WindowmasterTM automated window control system the payback on the system was just under six years!
More significant savings could be achieved if the NV ComfortTM System was allowed to completely replace the BMS.
If you want to do the best for your children’s learning outcomes, your running costs and our planet you need to seriously consider a Vento Australasia NV Comfort Natural Ventilation system in your existing or new school.
Australian Greenhouse Office, 2005, Working Energy Program: Heating, ventilation and air-conditioning (HVAC), Commonwealth of Australia, www.greenhouse.gov.au/lgmodules/wep/hvac/index.html, accessed 8 October 2007.
Buildings Energy Data Book, 2008, U.S. Department of Energy, Section 2.1.5, http://buildingsdatabook.eren.doe.gov/, accessed 10.12.11
Brager, G.S. & De Dear, R., 2001, ‘Climate, Comfort, & Natural Ventilation: A new adaptive comfort standard for ASHRAE Standard 55’, Center for Environmental Design Research, Center for the Built Environment, University of California, Berkeley.
The Natural Edge Project, 2011, Engineering Sustainable Solutions Program, http://www.naturaledgeproject.net/Sustainable_Energy_ Solutions_Portfolio.aspx, accessed 13.12.11
National Institute Science and Technology (NIST) Climate Suitability Tool, 2011
Nicol, J .F., & Humphreys, M. J., 2002, ‘Adaptive thermal comfort and sustainable thermal standards for buildings’, Oxford Centre for Sustainable Development, School of Architecture, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK
Origin Energy, 2008, Energy Efficiency Fact Sheet: Heating, Ventilation & Air Conditioning, http://www.originenergy.com.au/files/SMEfs_HeatingAirCon.pdf, accessed 13.12.11
Wargocki, P., 2010, ‘Classroom ventilation must be improved for better health and learning’, The REHVA European HVAC Journal, vol: 47(4), p. 35-39