How are the ventilation rates calculated?
Typically, the minimum ventilation rate is calculated by multiplying the total internal floor area by 0.3 l/s/m². The boost rate is calculated by assigning the following vent rates to each wet-room, and then adding them together. (kitchen 13l/s, bathroom 8l/s, utility 8l/s, WC 6l/s). It is important to note that these flow rates are to meet the minimum regulations. In many cases systems should be designed to allow for up to .5 l/s/m2. It may not always be required but when asked the system, should be able to do it comfortably, quietly and efficiently.