Fresh Air Intake - Panasonic S-36PU1E5A Technical Data & Service Manual

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1-9. Fresh Air Intake

1-9-1. Precautions Regarding External Air Intake
(1) Ventilation Load
Ensure that the design of the air-conditioner takes air-conditioning loads into consideration when external air intake is
involved.
(2) Restrictions on External Air Intake
Ensure that the design conforms to the restrictions on air intake volume stipulated in accordance with the model of
the indoor unit and the intake method. Consideration must also be taken to mixed air content listed in (3) below
without fail.
* If the air intake volume does not satisfy the required ventilation volume, air must be fed into the room separately with
the use of a total heat exchanger or a fresh air processing air-conditioner, etc.
(3) Mixed Air
The amount of external air intake must be set within the scope of the unit's usage conditions when external air and
internal air is mixed together. This is especially important in the following cases, in which it is necessary to either
feed external air into the room after it has been processed or reduce the amount of external air that is fed in.
When the external dew-point temperature is greater than the dry-bulb temperature of the air sucked into the unit
1
Ensure that processing is performed so that the external dew-point temperature is lower than the temperature of
the air sucked into the unit to prevent the risk of condensation building up.
In the case of low external temperatures
2
There are cases in which the temperature of mixed air is lower than the operating range of the unit if excessive
amounts of external air intake are used when the external temperature is low.
This problem is to be solved by either feeding external air into the room after it has been processed or reducing
the amount of external air that is fed in.
When used in combination with humidifiers
3
External air must always be processed when the external air temperature reaches freezing point to prevent the
risk of the humidifier freezing.
(4) Arranging Ducts and Filters in the Field
External air intake ducting must be arranged in the field.
External air filters must also be installed without fail in order to
prevent the intake of dust and grit.
(5) Thermal Insulation for Ducts
Ensure that all external air intake ducting is heat-insulated
without fail. Failure to observe this may result in the build-up
of condensation.
(6) External Air Intake Coupling
Ensure that the design for external air intake is coupled with
the fan blower operations of the indoor unit.
There are cases in which the dust that accumulates in the
filter is blown into the room if the external air is fed from the
filter. There are also cases in which the noise of external air
being fed into the room can be heard from the indoor unit if
external air is forcibly fed when the booster fan or other
components on the indoor unit are not operating.
(7) Booster Fan Selection
Select the booster fan in accordance with the resistance of
the external air intake duct (diagram on the pressure loss
characteristics of the air flow volume for flexible cylindrical
ducts) and the resistance prevalent inside the unit (external
air intake volume & resistance within unit / operation noise
characteristics).
(8) Attaching the External Air Intake Flange
Regarding the installation direction of the external air intake
duct, refer to the Installation Instructions provided with the
external air intake duct.
Flexible Cylindrical Duct
30
20
10
6
4
2
1
0.8
0.6
0.4
0.2
0.1
30
Air Flow Volume for Flexible Cylindrical
Duct-Pressure Loss
1-242
50 100 200 300 400 500
Airflow (m 3 /h)
ø100
ø125
ø150