# Mitsubishi Electric Lossnay series Technical Manual Page 18

For north america.

5.1 How to Calculate Each Approximate Load
5.1 A (US unit)
The ventilation air load can be calculated with the following formula if the required ventilation intake volume "Q CFM" is known:
(Ventilation air load) = γ · Q
F
3
2
= γ [lb/ft
] × S[ft
] × k × n [occupant/ft
γ : Specific air gravity - 0.0749 lb/ft
S : Building's airconditioned area
k : Thermal coefficient; generally 0.7 - 0.8.
n : The average population concentration is the inverse of the occupancy area per person. If the number of persons in the
room is unclear, refer to the Floor space per person table below.
Vf : Ventilation air intake volume per occupant
Refer to the Required ventilation air intake volume per occupant table below.
i
: Ventilation air enthalpy - Btu/lb
O
i
: Indoor enthalpy - Btu/lb
R
Floor Space per Occupant (ft
(According to the Japan Federation of Architects and Building Engineers Associations)
Office Building
General Design
43 - 75
Value
54
Required Ventilation Air Intake Volume Per Occupant (CFM per occupant)
Amount of Cigarette Smoking
Extremely Heavy
Quite Heavy
Heavy
Light
None
Caution
The amount of smoking that could be present in each type of room must be carefully considered when obtaining the
required ventilation volume shown in the table above.
· (i
- i
)
O
R
2
] × Vf [CFM / occupant] × (iO - iR): ∆i [Btu/lb]
3
2
)
Department Store, Shop
Average
5.4 - 21.5
32.3
Application Example
Broker's office
Newspaper editing room
Conference room
Bar
Cabaret
Office
Restaurant
Shop
Department store
Theater
Hospital room
CHAPTER 1
Ventilation for Healthy Living
Crowded
Empty
5.4 - 21.5
54 - 86
10.8
64.6
Required Ventilation Volume
Recommended Value
50
30
15
15
15
20
Theater or
Restaurant
Cinema Hall
10.8 - 21.5
4.3 - 6.5
16.1
5.4
Minimum Value
30
25
10
12
10
10
15
U-9