The efficiency of single-sided and cross ventilation in office spaces.

This paper reports on work carried out at BRE to address the need for guidance on designing for natural ventilation via single-sided and cross-ventilation in office spaces and the limits of application in terms of plan depth. Present guidance suggests that natural ventilation will be adequate up to 6 m from the ventilating facade. This leads to the conventional design of offices up to 6 m deep on either side of a central corridor, giving as a rule of thumb a width of 15 m for a building with natural cross-ventilation. The present work looks at the opportunities for going beyond these rules of thumb. The implications for thermal comfort and draught risk are also assessed. In the conclusions issues such as, local ventilation rates, ventilating air penetration from a facade, the use of artificial mixing (eg ceiling fans) on hot days, the position of windows, and means of enhancing internal air speeds and air change rates are discussed.