Daikin VAM Series Engineering Data page 73

EDMMT712101
Internal leaks
Effective ventilation volume
"Effective ventilation volume": Amount of outside air supplied (air volume) - Amount of return air leaked inside the equipment※
Indoor
SA
(Supply air)
※
Leakage of return air
10% or less
RA
(Return air)
Precautions when installing a booster fan in the duct
For large models, the pressure loss in the ducts will be larger than the static pressure outside the standard machine. If a booster fan or
the like is installed in such ducts, install the fan in the duct with the largest pressure loss whether it is the supply path [OA (outside air),
SA (supply air)] or the exhaust path [exhaust path RA (return air), EA (exhaust air)] to make sure that the pressure difference between
the supply path and the exhaust path does not become excessive in the main body of the total heat exchanger. The greater the pressure
difference in the main unit, the greater the air leakage inside the unit.
VAM-HVE/HVLT Series
= Net amount of fresh outside air introduced
Effective ventilation volume
90%
or more ※
EA
(Exhaust air)
OA
(Outside air)
※ For the leakage of return air inside the equipment, measure
the CO concentration on the indoor side of the main unit
2
with the rated external static pressure applied, so that the
ratio between the outdoor and indoor sides is even during
Outdoor
the ultra-high tap operation, and calculate how much CO
contained in the return air (RA) side has transferred to the
supply air (SA) side.
※ L eakage of the return air changes depending on how the
external static pressure is applied. When the ratio between
the outdoor and indoor sides is evenly set, the leakage will
be 10% or less, but when the ratio of the outdoor static
pressure is higher, the pressure difference between SA
(supply air) and RA (return air) becomes large, and the
amount of leakage tends to increase.
※ I f the ratio between the outdoor and indoor sides is 2:1,
the amount of leakage will increase by about 5% to 15%.
For the outdoor installation type, the duct outside of the
room is not required, so the calculation is performed with
the rated external static pressure applied to the inside of
the room instead. Therefore, the effective ventilation volume
may be less than 90%.
Control System
2
71