Technical Booklet K Ventilation·Page 24·2.14
Single room heat recovery ventilator as alternative
A continuously running single room heat recovery ventilator can replace a conventional intermittent extract fan in wet rooms, using minimum high rate from Table 2.1 and 50% as minimum low rate. No background ventilator is required in the same room, and total background ventilator area may be reduced by 2500 mm² for each such room.
Instead of a conventional intermittently used extract fan, a continuously running single room heat recovery ventilator could be used in wet rooms. It should use the minimum high rate given in Table 2.1 and 50% of this value as the minimum low rate. No background ventilator is required in the same room as the single room heat recovery ventilator. Furthermore, the total equivalent background ventilator area described in the tables below may be reduced by 2500 mm2 for each room containing a single room heat recovery ventilator.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet K - Ventilation.pdf