Part F of the E&W regs for intermittent ventilation is as follows, does not cover the trickle ventilation (air bricks, or gaps above/below doors to allow the air flow from fans to have an effect, so not a sealed room).
Fan is designed to remove the products of say a shower and showers are similar, size of room then is immaterial.
Section 5: New dwellings
Approved Document F Ventilation
|
Introduction to provisions
5.1 This Approved Document shows three main ways of complying with the ventilation requirements of the Building Regulations:
a. providing the ventilation rates set out in paragraphs 5.4 to 5.7; or
b. following the system guidance set out: for dwellings without
basements in paragraphs 5.8 to 5.10. This guidance covers all levels of design
air permeability. Alternative guidance is also provided for dwellings designed to an
air permeability leakier than (>) 5 m[SUP]3[/SUP]1(h.m[SUP]2[/SUP]) at 50 Pa where the developer from experience will not construct significantly more airtight dwellings (not better than 3 m[SUP]3[/SUP]1(h.m[SUP]2[/SUP]) at 50 Pa); or for dwellings with
basements in paragraphs 5.11 to 5.13; or
c. using other ventilation systems provided it can be demonstrated to the
Building Control Body that they satisfy the Requirement, e.g. by showing that they meet the moisture and air quality criteria set out in Appendix A.
5.2 There should be reasonable access for maintenance. This should include access for the purpose of changing filters, replacing defective components and cleaning ductwork.
Table 5.1 Note that extract fans lower the pressure in a building, which can cause the spillage of combustion products from open-flued appliances (i.e. the combustion gases may fill the room instead of going up the flue or chimney). This can occur even if the appliance and the fan are in different rooms. Ceiling sweep fans produce air currents and hence focal _epressurization, which can also cause the spillage of flue gases from open-flued gas appliances or from solid fuel open fires. In buildings where it is intended to install open-flued combustion appliances and extract fans, the combustion appliance should be able to operate safely whether or not the fans are running. A way of showing compliance in these circumstances would be to follow the guidance given in Approved Document J on both the installation of the appliances and tests to show that combustion appliances operate safely whether or not fans are running.
Table 5.1 a
| Extract ventilation rates
| | |
Room
| Intermittent extract
| Continuous extract
|
|
| Minimum rate
| Minimum high rate
| Minimum low rate
|
Kitchen
| 30 I/s (108m[SUP]3[/SUP]/hr) adjacent to hob; or
60 I/s (216m[SUP]3[/SUP]/hr) elsewhere
| 13 I/s (46.8m[SUP]3[/SUP]/hr)
| Total extract rate should be at least the whole dwelling ventilation rate given in Table 5.1 b
|
Utility room
| 30 I/s (108m[SUP]3[/SUP]/hr)
| 8 I/s(28.8m[SUP]3[/SUP]/hr)
| |
Bathroom
| 15 I/s (54m[SUP]3[/SUP]/hr)
| 8 I/s (28.8m[SUP]3[/SUP]/hr)
| |
Sanitary accommodation
| 6 I/s (21.6m[SUP]3[/SUP]/hr)
| 6 I/s (21.6m[SUP]3[/SUP]/hr)
| |
Table 5.1 b
| Whole dwelling ventilation rates
| | | | |
| Number of bedrooms in dwelling
| | | | |
1
| 2
| 3
| 4
| 5
| |
Whole dwelling ventilation
rate [SUP]b [/SUP](I/s)
| 13
| 17
| 21
| 25
| 29
|
Notes:
a. In addition, the minimum ventilation rate should be not less than 0.3 Its per m[SUP]2 [/SUP]of internal floor area. (This includes all floors, e.g. for a two-storey building add the ground and first floor areas.)
b. This is based on two occupants in the main bedroom and a single occupant in
all other bedrooms. This should be used as the default value. If a greater level of occupancy is expected add 4 Vs per occupant.
