Civil Engineering Reference
In-Depth Information
Fig. 4.14
Humidity mass balance inside a room
Table 4.11
Human humidity generation rate
Activity level
Met
G
W
(g/h)
Light
<
1.72
30
−
120
Medium
1.72
−
3.95
120
−
200
Heavy
>
3.95
200
−
300
Source:
(Moon
2005
)
2002
; Moon
2005
), obtaining results like those shown in Table
4.11
. However,
as in the temperature model, this approximation causes abrupt changes in indoor
humidity each time a person goes into the room. To solve this situation, it has
been considered that people add water vapour to the indoor air mainly by means
of respiration and transpiration (Tenwolde and Pilon
2007
).
More specifically, during respiration the human body loses water vapour by
evaporation from the respiratory tract to the inhaled air (ASHRAE
2009
). Hence,
the total humidity generation rate
G
W
can be estimated according to Eq.
4.39
.
G
W
=
q
res
(
W
res
−
W
a
in
)
(4.39)
