Daikin VAM-FA8VE Technical Data Manual page 258

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• HRV • VKM-GA(M)V1
<Mechanical ventilation>
Whole ventilation
This is to replace all air in the room with fresh air. This
system is effective for rooms in which there is a source of
smoke, steam or odor.
Local ventilation
This is to replace air in a limited area where the air is polluted. This is
effective for cases where the source of pollution is stationary and
concentrated. Combined use with a hood is effective for removing
highly contaminated air.
<Important supply flow>
To ensure effective ventilation, sufficient air intakes should be provided.
To ensure stable ventilation, the same amount of fresh air as exhausted should be supplied.
Size and location of air intakes
1. Size
Mechanical ventilation fan rated capacities indicated on a catalogue can be used on condition that the
same amount of air is fed into the room through the air intakes. Smaller air intakes will reduce the
capability of the ventilation fan. Generally, the air intakes should be larger than the ventilation fan
opening. Larger air intakes can reduce the air velocity from the intake, so that persons, when standing
near the intake, do not feel discomfort.
Discomfort
due to higher
velocity
Air intake
2. Location of exhaust (fans) and intakes
For whole ventilation, air intakes should be located as far from the fans as possible. For local ventilation
intended for narrower, limited space, air intake(s) should be located as close to the fan as possible so
that the surrounding areas can be less affected.
For large rooms, multiple air
intakes should be located
dispersedly and as far from
the exhaust as possible to
ensure uniform ventilation
throughout the room.
Air intake
Good example
Dispersed location of
ventilation fans
3. For confined rooms
Ventilating a bathroom with the door tightly closed may
cause the water trap of the drainage to break, which results
in the backflow of odor into the bathroom. In cold weather
areas, ventilating a confined room using a stove with a
natural exhaust ventilation duct may invite backflow of air
into the stove through the exhaust duct, leading to
dangerous combustion condition.
• HRV • Heat Reclaim Ventilation
Supply
Noisy Smooth air flow
Exhaust
Smaller Smaller velocity
flow
Air intake
Larger ill-ventilated areas
Air intake
Bad example
Smaller ill-ventilated areas
Air intake
Good example
Exhaust
Dirty air
Supply
Cooking range
hood fan
Ventilation coverage
Exhaust
Cooking range
Exhaust
Backflow of air through
the drain piping : cold and smelly