Sound Levels Of Lossnay Units With Built-In Fans; Attaching Air Filters; Constructing The Ductwork; Bypass Ventilation - Mitsubishi Electric Lossnay series Technical Manual

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2. Sound Levels of Lossnay Units with Built-in Fans

The sound levels specified for Lossnay units are generated from tests conducted in an anechoic chamber. The sound levels
may increase by 8 to 11 dB according to the installation construction material and room contents.
When using Lossnay units in a quiet room, it is recommended silencer duct, silencer intake/exhaust grill or silencer box be
installed.

3. Attaching Air Filters

An air filter must be mounted to both the intake and exhaust air inlets to clean the air and to prevent the Core from clogging.
Periodically clean the filter for optimum Lossnay unit performance.

4. Constructing the Ductwork

Always add insulation to the two ducts on the outdoor side (outdoor air intake and exhaust outlet) to prevent frost or
condensation from forming.
The outdoor duct gradient must be 1/30 or more (to wall side) to prevent rain water from going into the system.
Do not use standard vent caps or round hoods where those may come into direct contact with rain water.
(A deep hood is recommended.)

5. Bypass Ventilation

Do not operate "bypass ventilation" when heating during winter. Frost or condensation may form on the main unit.

6. Night purge function

Do not use the night purge function if fog or heavy rain is expected. Rain water may enter the unit during the night.
7. Transmission Rate of Various Gases and Maximum
Workplace Concentration Levels
Measurement
Conditions
Measurement method
• Photoacoustic
Isopropyl alcohol
Spectroscopy (PAS)
for SF
6
• Non-dispersive
Infrared Detector
(NDIR) for CO
2
Ammonia
• Gas Detector Tube
for others
The fans are
positioned at the air
supply/exhaust
Carbon dioxide
suction positions of
the Lossnay Core
Measurement
conditions:
80.6°F (27°C), 65% RH
Sulfur hexafluoride
* OA density for CO
2
is 600 ppm.
CHAPTER 5
Air Volume
Gas
Ratio
Q
/Q
SA
RA
1.0
1.0
1.0
1.0
System Design Recommendations
Exhaust Air
Supply Air
Concentration
Concentration
C
(ppm)
C
(ppm)
RA
SA
2,000
50
70
2
44,500
1,400
27.1
0.56
Transmission
Max. Workplace
Rate
Concentrations
(%)
(ppm)
2.5
400
2.9
50
1.8
2.1
U-53

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