Room Height (Internal for 'Airwind' & 'Cellwind', and External by changeable default for 'Coldwind') is entered by clicking on the Wall Height button. A facility is provided for entering additional ceiling space air volume within the ceiling input routines that are accessed separately through the Ceiling button. This is appropriate for example where a vaulted space above and open to the general ceiling height level occurs but should not be confused with air space above the ceiling which is separately considered in Roof design inputs. Room height limits are 0.5 metres minimum and 20 metres maximum.