Special Schools and Designated Units, where Category I needs of pupils may be complex and varied, including pupils with physical difficulties or profound and multiple learning difficulties Where pupils or adults may be wet and Category II partially clothed for a significant length of time, such as swimming pools young children under 5 years old or those Category I with physical disabilities may be wet or partially clothed for a significant length of time. More rapid air movement leads to greater chilling by evaporation and to compensate, a higher design temperature is required Category IV shall only be used in classrooms and other teaching spaces where there is local control over the room ventilation with variable speed control with override control by the teacher. The air quality criteria regarding CO2 levels must still be met. Table 104 Recommended draught criteria for mechanical ventilation systems to provide thermal comfort Draught criteria to provide thermal comfort Winter Summer and mid-season ∆T ∆T (Troom, Category of (Min Maximum Maximum operative - space/activity maintained air air plume local operative velocity velocity air temp) temp - plume When Troom (m/s) (m/s) local air or ≤25oC temp) Tcomf 1.5 0.15 1.5 0.15 I 2 0.2 2 0.2 II 3 0.25 3 0.25 III 4 0.3 5 0.3 IV
Special Schools and Designated Units, where needs of pupils may be complex and varied, including pupils with physical difficulties or profound and multiple learning difficulties Category I Where pupils or adults may be wet and partially clothed for a significant length of time, such as swimming pools Category II young children under 5 years old or those with physical disabilities may be wet or partially clothed for a significant length of time. More rapid air movement leads to greater chilling by evaporation and to compensate, a higher design temperature is required Category I Category IV shall only be used in classrooms and other teaching spaces where there is local control over the room ventilation with variable speed control with override control by the teacher. The air quality criteria regarding CO2 levels must still be met. Table 104 Recommended draught criteria for mechanical ventilation systems to provide thermal comfort Category of space/activity Draught criteria to provide thermal comfort Winter Summer and mid-season ∆T (Min maintained operative temp - plume local air temp) Maximum air velocity (m/s) ∆T (Troom, operative - plume local air temp) When Troom ≤25oC or Tcomf Maximum air velocity (m/s) I 1.5 0.15 1.5 0.15 II 2 0.2 2 0.2 III 3 0.25 3 0.25 IV 4 0.3 5 0.3
Annex_2F_Mechanical_Services_and_PHE__Technical_Annex_.docx