International trends in the education of students with special educational needs

15.2 Temperature, Humidity and Ventilation 


School and classroom temperature, humidity, ventilation, and the control of mould, dust and mildew are important factors that need to be controlled. For children with multiple sclerosis, for example, excessive heat can affect them and create classroom problems, while for learners with asthma, excessive humidity and poor air quality can restrict their participation (Crowther, 2003). Even in developed countries such as the US, there is evidence that indoor air quality is far from satisfactory. In 1995, for example, around 20% of children in American schools were estimated to suffer from poor quality indoor air quality, which often leads to irritated eyes, nose and throat, upper respiratory infections, headaches and sleepiness (General Accounting Office, 1996). In such situations, ventilation needs to be improved to deliver adequate supplies of fresh air and to help dilute or remove contaminants. 


The position of the World Health Organization is that, in temperate climates, the optimum temperature for indoor working is between 18C and 24C. This constitutes a thermally comfortable environment. In New Zealand, the Ministry of Education states that classrooms should be maintained at 18-20C (Ministry of Education, nd), while in the UK, minimum temperatures for classrooms are given in the Education (School Premises) Regulations, SI No2, 1999 as 18C (64.6F), but no maximum temperatures are specified. In New Zealand, a Heat Stress Index (HIS) is used as a guide. This is a formula that produces a number that represents the combined effect of the air temperature, radiant heat and the humidity.

15.3 Lighting

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  the visual environment affects learners’ ability to perceive visual stimuli and affects 
their mental attitudes and, therefore, their performances;
  
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  day-lighting has the most positive effects on learners’ achievement;
  
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  since day-lighting as a sole source of lighting is not feasible, it should be supplemented by automatically controlled electric lighting that dims in response to daylight levels;
  
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  lighting should be as glare-free and flicker-free as possible, especially when computers are being used (Higgins et al., 2005).
  

Recent Irish and Australian studies have drawn attention to the increasing incidence of myopia, implicating children’s reduced time spent outside. For example, Saunders’ (2015) research shows that 23% of British 12 and 13-year-olds have myopia¹ , compared to just 10% in the 1960s. More research suggests that British children are three times as likely to be short-sighted as Australians, who spend more time outside. According to Morgan et al. (2012), myopia has emerged as a major health issue in east Asia, because of its increasingly high prevalence in the past few decades (now 80–90% in school-leavers, compared with earlier estimates of 20%), and because of the sight-threatening pathologies associated with high myopia, which now affects 10–20% of those completing secondary schooling in this part of the world. The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside. In turn, this leads to decreased levels of dopamine in the eye (dopamine seems to prevent elongation of the eye).

Lighting needs to enable learners to see the details of given tasks easily and accurately in lighting conditions that pertain during the day and during the year. A major difference between classrooms and most other environments is that learners must constantly adjust their vision between ‘heads-up’ and ‘heads-down’ reading conditions. Lighting should take account of this range of demands on learners’ vision (The Collaborative for High Performance Schools, 2002).

Here are some suggestions:

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  Ensure that children receive two-three hours a day of outdoor light (Morgan et al., 2012).
  
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  Maximise the use of day-lighting, but supplement it by electric lighting, which can, if possible, be automatically dimmed in response to daylight levels.
  
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  Try to use a combination of direct and indirect lighting to reduce glare and reflections as much as possible.
  
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  Place mirrors on walls opposite windows to maximise natural light.
  
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  Be quick to replace burnt-out lights.
  
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  About 20% of a classroom’s wall space should consist of windows.
  
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  Ensure that the contrast between a task object and its immediate background is 
sufficient to enable learners to clearly view the task.
  
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  Use convex whiteboards to reduce glare.
  
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  Check that fluorescent lighting is in good working order as excessive flickering could 
trigger a seizure in learners with photosensitive epilepsy (Anshel, 2000). Also, note that fluorescent 
lighting can be aversive to learners with autism spectrum disorders.
  
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  The lighting level for computer use should be about half as bright as that normally 
found in a classroom.
  
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  Strictly enforce the amount of time that learners continuously use computers. A 10-minute break every hour will minimise focusing problems and eye irritation.
  
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  Develop the ‘20/20/20 rule’: every 20 minutes, take 20 seconds and look 20 feet (6 
meters) away.
  
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  Carefully check the height and angle of computer screens (just below eye level and about 20 degrees angle), and the distance from the eyes (18-26 inches or 45-66 cm).
  
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  Ensure that there is no glare on the screen (use a mirror to check sources of glare).
  

Since much classroom learning takes place through listening and speaking (estimates vary from 50-90 per cent, according to Schmidt et al., 1998), it is essential that learners can hear educators’ speech clearly. Unfortunately, this is not always the case, with typical classrooms in many developed countries providing inadequate acoustical environments. In a New Zealand study of 106 classrooms, for example, it was found that only 4% had acceptable noise levels for instruction (Blake & Busby, 1994). This situation, which is by no means limited to New Zealand, has a major impact on the students’ opportunities to learn, especially for those with mild or fluctuating hearing loss, learning disabilities, attention disorders, language disabilities

In providing an optimal acoustic environment, three inter-related factors should be attended to (ASHA Working Group on Classroom Acoustics, 2005; ASHA Special Interest Division 16, and Educational Audiology Association, 2002):

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  Poor signal-to-noise ratio (i.e., an educator’s voice compared with background noise). For example, if a teacher’s voice arrives at a learner’s desk at 50dB and the background noise is 55dB, the resulting signal to noise ratio (SNR) is -5. This compares unfavourably with an optimum SNR of +15dB for learners with normal hearing and very unfavourably with the requirements of learners with special educational needs.
  
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  Excessive sound reverberation (i.e., sound bounce, or echo). Technically, this is measured by ‘reverberation time’, which is the time between the cessation of a sound source and a measured decay of 60db. Ideally, this should be no longer than 0.4 - 0.6 of a second.
  
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  High levels of ambient noise (i.e., the noises consistently present in an empty classroom). These should be no louder than 30-35 dB.
  

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  Use sound-absorbing materials like large cork bulletin boards, carpets under noisy equipment, and felt under chairs to reduce annoying scraping sounds.
  
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  Insulate walls and ceilings and use dividers covered with thick felt or material to absorb noise within and between classrooms. (Note, however, that there is a risk that materials such as felt may gather dust and jeopardise the health of asthmatic learners.)
  
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  Separate noisy and quiet areas. For example, locate the reading corner and the play area at opposite ends of the room.
  
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  Model appropriate voice levels (for example, ask the learners to distinguish between ‘inside’ and ‘outside’ voices).
  
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  Encourage learners to speak quietly in group activities and when moving furniture.
  
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  Use music to calm the class (but take care that this does not itself become ‘noise’ and 
forces learners to speak even louder to make themselves heard).
  
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  Keep doors and windows closed, provided there is adequate ventilation.
  
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  Check the noise levels of any heating, ventilation and air conditioning system in your classroom.
  
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  Involve an audiologist and/or a speech and language therapist in working out ways to make classrooms acoustically satisfactory.
  

Recent research has highlighted the importance of considering the complex interactions and additive effects among various aspects of indoor environmental quality on student achievement. For example, in a UK study, researchers found the following classroom characteristics related positively to achievement: (a) light: e.g., classrooms receive natural light from more than one orientation, and they have high quality and quantity of electric lighting; (b) choice: e.g., classrooms have high quality and purpose-designed furniture, fixtures and equipment, including ergonomic tables and chairs; (c) flexibility: various zones can allow varied learning activities at the same time, and teachers can easily change the space configuration; (d) connection: wide corridors can ease movement, and pathways have clear way-finding features; (e) complexity: classrooms are designed with quiet visual environments balanced with a certain level of complexity; and (f) colour: warm colours in senior grades’ classrooms and bright, cool colours in junior grades’ classrooms (Barrett, 2013).