ENGLAND & WALES: Approved Document F 2010
(ADF2010)
Calculating the Whole Dwelling Ventilation Rate
(trickle rate)
The low rate is calculated by taking the higher of two
below calculations.
1.
Calculate the floor area in m
2
of the heated envelop
of the dwelling then multiply this by 0.3l/s (litres per
second) to give the trickle rate in (l/s) for the whole
dwelling.
e.g. m
2
floor area x 0.3l/s = trickle rate in l/s
2.
Calculate the total amount of occupants for the
dwelling by using table 1 (table 5.1 in ADF2010).
Reference the number of bedrooms in the dwelling to
the whole dwelling ventilation rate on table 1, remember
to add any additional occupants in the additional
bedrooms after the first, by adding 4l/s per additional
occupant.
Calculating High Rate (boost)
The high rate is calculated by adding the minimum high
rate for each of the wet rooms within the dwelling
(kitchen, bath, utility etc.) together from the values in
table 2 (tab. 5.1a in ADF2010).
ENGLISH
Tab. 1 Whole dwelling ventilation rates.
Number of bedrooms in dwellings
1
2
3
4
5
Whole
dwelling
ventilation
rate
a,b
(l/s)
13
17
21
25
29
a.
In addition, the minimum ventilation rate should be
not less than 0,3 l/s per m
2
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 the occupants in the main
bedroom and a single occupant in all other bedrooms.
This should be used as the default values. If a greater
level
Tab.2 Extract ventilation rates
Room
Intermittent extract
Continous extract
Minimum rate
Minimum high rate
Minimum low rate
Kitchen
30 l/s adjacent to hob;
or 60 l/s elsewhere
13 l/s
Total extract rate should be
at least the whole dwelling
ventilation rate given
in table 1
.
Utility room
30 l/s
8 l/s
Bathroom
15 l/s
8 l/s
Sanitary
accommodation
6 l/s
6 l/s
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