Retrotec USACE - Manual (Page 363)

Appendix H H3
q
inf
= infi ltration airfl ow rate, m 3 /s
t
room
= room air temperature, °C
t
out
= outdoor air or soil temperature, °C
Infi ltration airfl ow rate can be calculated as
q
inf
=
√
_________
2( µF)
i
␳∆p
i
where
∆P
i
= the difference of static pressure between the air inside and outside the
building, Pa, measured using a micro-manometer or calculated based on
the difference in temperatures of external and internal air and the speed
of a wind
(µF )
i
= the equivalent area of cracks in the building envelope, m 2 , dependent on
type of structure
Techniques and instrumentation for the measurement and evaluation of air
infi ltration in buildings are described in Appendix E.
H.5 Internal Heat Gains
In defi ning the heating load of a building, the internal heat gains, Q
int.load
, must
be taken into account as much as it can be utilized in heating. The utilized heat-
ing effect recovered from exhaust air by heat recovery equipment considered
di-heat recovered from exhausted air by heat recovery equipment Q
HR
is a part
of the internal heat gain. The internal heat gain consists of heat released from
process equipment, lighting, other electrical loads, and people. In defi ning net
internal gain, the heat gain through the building envelope must be taken into
account. The internal heat gain shall also be taken into account when estimat-
ing the cooling load of the building.
H.5.1 Cooling Load
The cooling load of a building consists of heat released from internal and ex-
ternal sources.
External factors:
Solar radiation through fenestration and other parts of the building enve- ■
lope