The recently opened Ark Academy, Wembley Park on Forty Avenue, London, features innovative, high-quality buildings especially designed to inspire pupils. Forming part of the natural ventilation strategy, which helps to support calm and ordered learning inside the inviting and well-equipped classrooms, is a Monodraught windcatcher system featuring special acoustic linings that also makes an important contribution to the academy’s extremely high standards of acoustic insulation.
To achieve a workable solution using natural ventilation, consultant AECOM followed the guidelines set out in the ‘Building Bulletin for Schools’ to determine the ventilation rates required for the teaching spaces to provide fresh air to the occupants and also to limit overheating during summer months. This was used to determine the volume of fresh air the roof mounted Monodraught Windcatcher natural ventilation systems needed to provide for individual teaching spaces.
AECOM outlined the general concept for the natural ventilation system and provided the minimum and maximum ventilation rates for the various spaces. Monodraught then calculated the sizes of the windcatchers, which were fitted to rooms on the top floors of the building, and provided special powertrack controllers to enable the windcatchers to operate with the academy’s BMS.
Due to noise sensitivity within the Arc Academy, the windcatchers needed to meet particularly stringent levels of acoustic insulation and Monodraught provided a number of additional natural ventilation solutions for the academy’s buildings, as AECOM’s William Western explains: “The windcatchers were used primarily in spaces where we couldn’t naturally ventilate using opening windows due to the height required. For example, opening windows weren’t a viable solution in the standard classrooms due to the acoustic requirements needed to minimise noise on the site.”
Special acoustic measures were specified due to the proximity of the school to a main road at the north of the site and two main roads to the east. Fortunately, Monodraught was able to provide a customised solution within its windcatchers using very effective acoustic linings to reduce noise.
Monodraught was also able to provide a solution in areas where higher ventilation rates were needed due to excessive heat gains, for example in south facing classrooms. The windcatcher Sola-boost natural ventilation option was specified to provide the higher ventilation rates needed during summer months, when temperatures increase and higher solar gains occur. Again, the Monodraught solution proved to be very effective for those spaces.
The Sola-boost systems combine efficient natural ventilation with an ultra-quiet, high-efficiency solar-driven fan, which provides true energy-free operation without using carbon intensive batteries. The Monodraught units are optimised to deliver maximum power to the fan under full sun conditions, so the brighter the sun the greater the ventilation rate. Fully automatic controls within the system regulate the room temperature and internal air quality, including CO2 levels, whilst maximising energy savings.
And finally, William Western says Monodraught suncatcher systems provided an ideal solution for some of the various internal spaces where opportunities to provide natural daylight and natural ventilation would be otherwise difficult to achieve.