Energy-Conscious School Construction

Introduction

Of late, schools have been noted for high energy consumption. For instance, schools in the US consume energy worth US$ 6 billion every year. In France, in the year 2008, schools alone consumed a total of 225 kWh/m2. In yet another study in Slovenia involving 24 schools, the average energy consumption was found to be 267 kWh/m2 every year. As such, school buildings should be constructed with energy consciousness in mind. This goes a long way to save on energy expenditure as well as improve the learning environment of the students. The design adopted largely depends on the climate of the area in which the school is built. As is expected, a school in a hot arid region cannot be designed the same way as a school in a boreal climate. This paper outlines the design considerations of two different schools, one in the boreal climate of Canada, and the other in the arid climate of Arizona, USA (Research Gate, 2018).

Case Study 1 - Emily C. General Elementary School - Boreal Climate

Emily C. General Elementary School is located along Onondaga Road within the Six Nations of the Grand River reserve in the Province of Ontario in Canada. Six Nations of the Grand River is a very populous First Nation in Canada. It covers about 18,000 hectares along the Grand River. Similar to most other provinces of Canada, Ontario’s climate is classified as continental. This is characterized by long, very cold winters and short summers. The area in which the Emily C. General Elementary School is located receives cold, dry arctic air from the North for the better part of the year. To enable the students to experience thermal comfort, the school was creatively designed by architect Brian Porter, MRAIC (Atkins, 2012). The school’s design was based on traditional building precedents. The school is essentially oriented to the compass directions. The middle axis is fitted with a skylight whose main purpose is lighting up the school using the natural daytime sunlight. The position of this major skylight makes the school act as a mega sundial. The passage of the day from dawn to dusk is well tracked by the school goers. The change of the overhead sun’s position during the different seasons is also easy to observe (Atkins, 2012). The classroom walls are largely made of bricks. Research shows that brick is the most energy-efficient building material. Bricks considerably control the temperature inside the classrooms. Bricks have a high thermal mass in the sense that they are able to absorb and retain heat from solar radiation. This keeps the classroom interior thermally comfortable without the need to use artificial heating. The result is a huge reduction in electricity bills for the school (Torgal, n.d.).

Nearly all the classrooms are fitted with a wooden ceiling. Wood is a very good insulator. This means it inhibits the transfer of heat across it. In this sense, it prevents the escape of heat from the classrooms to the outside which is normally cold. Such natural insulation eliminates the need to over-rely on artificial heating systems to attain thermal comfort. Also, psychologically, rooms with wooden ceilings feel warmer. The wood used for the ceiling is mostly light-colored. This adds to the brightness in the classrooms even when using only the natural sunlight. This also saves electricity bills (Wooden ceiling and panelling boards, 2018). The architect compared three different heating and ventilating systems before the construction of the school building commenced. He settled on the ground-source heat exchange and heat pump system. The initial cost for this system was a bit high, but the projected costs during its design life span of 20 years were relatively low. This system provides both heating and cooling. As such, it has a very little negative impact on the environment (McDowall, 2007).

Case Study 2 - Desert Edge High School - Arizona - Hot and Dry Climate

Desert Edge High School is located in Goodyear, Arizona, near the Estrella Mountains. Arizona is basically an arid or semi-arid climate (Aguafria.org, 2020). The average annual precipitation stands at around 12 inches. Part of Arizona is purely desert with summer daytime temperatures going as high as 45 degrees celsius. During winter, the temperatures can get to as low as 15 degrees celsius. In such a region, students would want a classroom with interior temperatures lower than the outside temperatures Aguafria.org, 2020). Desert Edge High School was awarded a LEED Silver Certification owing to its ingenuine design for the desert climate. The construction of the school was done in two phases, the first one being completed in 2002 while the second phase being completed in 2005. The contractor in charge was Adolfson and Peterson Construction. The architect for the project was Emc2 Architects. Statistics have it that the school saves $58,000 every year in energy costs. This is 28% more energy-efficient than similar standard designs. The building has a total area of 90,620 SqFt. In addition, the school saves 88% of potable water and uses it for irrigation. 38% of potable water is also saved for domestic purpose. The school has an interactive touch screen within its compound which is meant to educate visitors on how sustainability has been implemented in the school building (Www1.eere.energy.gov, 2009). The school building has electricity meters installed to track energy consumption. This keeps the school management up to date with all information regarding energy expenditure in the school. Being located in a hot climate, the main school building features large overhangs to reduce the amount of solar radiation that falls onto the windows and walls of the classrooms. This way, heating up of the interior of the classrooms is greatly reduced. The result is a cool interior even when the outside sun is scorching hot (Www1.eere.energy.gov, 2009).

The classrooms have multiple light-switching fixtures, all of which are fitted with both daylight and occupancy sensors. When daylight is sufficient for use by the students, the lights automatically go off. This greatly saves electricity bills. Also, when the classrooms are empty, the lights automatically switch off (Www1.eere.energy.gov, 2009). The urinals for the boys and girls are waterless. This saves a lot of water which would have been used to flush the urine every few minutes. All plumbing fixtures are of a low-flow design, including the had was basins. Adhesives, paints, sealants, and coatings used in the building have a low content of volatile organic compounds. VOCs are unstable, carbon-containing compounds that vaporize quite easily and combine with other elements to produce carbon gases. VOCs have also been linked to cancer, kidney and liver damage. By using low VOC materials, the design saves the ozone layer as well as the health of the students (Www1.eere.energy.gov, 2009). The school is landscaped with drought-resistant plants that require only a little water to survive. This saves a lot of water that would have been used for irrigation. Grates and CO2 sensors are installed on the entryways to boost the air quality inside the classrooms. The classroom windows are fitted with Low-E glass with a gray tint and an assembled U-factor of 0.33. Double glazing is used and in some instances, a third pane is used for micro blinds. The walls are generally made of masonry blocks with R-19 cavity insulation. The school is oriented on an east-west axis to make maximum use of daylighting and to benefit from passive solar gain during the winter months (Www1.eere.energy.gov, 2009).

Discussion

The above two schools differ significantly in their design. Whereas Emili C. General Elementary School mainly aims at reducing the cold in the classroom, Desert Edge High School majorly aims at decreasing excessive heat in the classrooms. This is because of the climatic zones in which they are located. Emily C. General Elementary is built in a boreal climatic zone while Desert Edge High School is located in an arid area. Buildings in cold areas tend to spend more energy in heating up the interiors. On the contrary, buildings in hot areas spend more energy in cooling the inside of rooms. Both heating and cooling systems are expensive in terms of energy expenditure. The two schools discussed above were designed and built with sustainability in mind. Sustainability features include the building envelope, windows, roofing, ceiling, doors, HVAC system, water usage, lighting system, and design for the community.

Recommendations

The designs for both schools in this case study are generally sufficient as regards sustainability. However, there are omissions that need to be addressed for both schools. For Desert Edge High School, it is recommended that they should recycle the human waste for use as fertilizers in their farms. For Emily C. General Elementary School, it is recommended that they integrate daylight and occupancy sensors in the lighting system to avoid lights staying on even when no one is using them.

Conclusion

Design for climate is very essential, especially in schools which are culprits of excessive energy consumption. If well integrated into the design, sustainability features are a great way to cut on energy costs.

References

Hallin, S. (2017). Minimising Excessive Energy Consumption in Schools While Maintaining Optimal Air Quality. Open Journal of Optimization, 06(04), pp.149-163.

McDowall, R. (2007). Fundamentals of HVAC systems. Atlanta, Ga.: American Society of Heating, Refrigerating and Air-Conditioning Engineers.

Simmons, K. (2008). Skylight. London: John Murray.

Torgal, P. (n.d.). Eco-efficient masonry bricks and blocks.

Wooden ceiling and panelling boards. (2008). Pretoria: Standards South Africa.