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5.3 Ventilation load during heating
Classification of heating load
Class
Indoor heat
(a)
loss
Outdoor air
(b)
load
During heating, the heat generated by people and electrical equipment in the room can be subtracted from the heating load.
However, as the warming up time at the start of heating is short, this generated heat may be ignored in some cases.
Percentage of load
Outdoor
Indoor heat
air load 41.9%
loss 58.1%
2
56.0 W/m
77.7 W/m
Internal heat loss
In terms of load classification, the internal heat loss is the value of the outdoor air load subtracted from the approximate
heating load.
Internal heat loss = 133.7 W/m
Heating load per unit area
When the outdoor air volume per person is 25 m
heating load will be approximately 133.7 W/m
Outdoor air load
Air conditions <Standard design air conditions in Tokyo>
Outdoor air
Cooling
Indoors
2
When the load per 1 m
the following is obtained:
Outdoor air (ventilation) load = 1.2 kg/m
2
= 201.0 kJ/h·m
(56 W/m
The Lossnay recuperates approximately 70% of the outdoor air load and saves on approximately 30% of the total load.
Heat lost from walls (q
Heat lost from glass (q
Heat loss from conduction & convection (q
Accumulated heat load in walls (q
Sensible heat (q
)
FS
Latent heat (q
)
FL
2
2
133.7 W/m
2
2
– 56.0 W/m
= 77.7 W/m
2
.
Dry bulb temp.
Relative humidity
0 °C
20 °C
of floor area with a ventilation volume of 25 m
3
× 0.2 persons/m
2
)
CHAPTER 1
)
WS
)
GS
)
GS
)
SS
Type of load
Outdoor air load
Internal heat
Total
Conditions: Middle floor of a general office building facing south.
2
3
/h, and the number of persons per 1 m
Wet bulb temp.
50%
-3 °C
50%
13.7 °C
3
/h·person is calculated with the above air conditions,
2
3
× 25 m
/h·person × 33.5 kJ/kg
Ventilation for Healthy Living
Load
56.0 W/m
77.7 W/m
133.7 W/m
2
is 0.2 persons, the approximate
Enthalpy
Enthalpy difference
5.0 kJ/kg
38.5 kJ/kg
2
2
2
33.5 kJ/kg
13
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