The windows, which were installed at the newly opened Steiner Academy in Exeter, were specified because they could provide almost twice the free air flow of standard top hung or casement windows and could deliver a greater number of air changes per hour.
Compared with a casement window, a parallel window increases air flow all the way around so that fresh air is drawn in at the bottom and warm, stale air is expelled at the top. This creates full circulation of the air within the room and, at the same time, the balanced air flow around the entire opening reduces the potential for draughts.
With levels of ventilation known to have a direct effect on concentration and learning in schools, natural ventilation is a key priority for many designers looking to go beyond the minimum requirements of the Building Regulations Part F (Ventilation).
At Steiner Academy, the windows were specified by architects AHR Global in Bristol. Trade fabricator Interframe had impressed AHR on a previous new build school scheme in Devon and on this project they were closely supported by REHAU who worked with them to come up with a practical and cost effective window solution which could deliver the free air flow required in openings up to 2100mm high.
A key benefit of parallel windows is that they don’t impact on the look of a building’s façade and maintain a consistent reflective view, with low G-value glass used to reduce solar gain. At Steiner Academy, all of the 150 plus windows, doors and screens installed were also coloured in a contemporary looking smooth RAL 7016 grey foil.
REHAU’s commercial sales manager Steve Tonkiss said: “Interframe were able to meet the exacting requirements of this project using our standard REHAU TOTAL70C profile. This was a huge advantage because it meant that they weren’t holding stock of additional profiles and, because of the strength of the system, they could manufacture the large window sizes required.”
The Steiner Academy was a £7.6m construction and refurbishment project carried out by Willmott Dixon. The through school, which accommodates more than 600 pupils from the ages of four to sixteen, is a state funded free school built on the 13 acre site of an old Exeter University Halls of Residence.
The Grade II listed Thomas Hall building on the site has been refurbished and the new 4,707m² two storey building where the parallel windows have been installed has been constructed alongside.