Installation
CLCH-SVX014B-EN
15
If combustion air is ducted to the vestibule, it is strongly
recommended that an experienced gas heat technician
check the system and emission levels in the exhaust flue at
start up. Carbon dioxide should be between 8.2 and 9.4
percent. This corresponds to the allowable range of excess
air needed for combustion. The additional static pressure
of the inlet air duct may change the fuel-air ratio slightly
necessitating system adjustment.
Combustion air cannot be ducted directly to the
combustion air fan. The airflow through the vestibule is
needed to keep the temperatures in the vestibule down.
Duct Transitions
When the gas heat section is the last section of the air
handler, and duct transitions should be smooth and
uniform from all sides. Follow recommendations for duct
transitions from SMACNA.
Fasten the ductwork directly to the ductwork opening.
When using lined ductwork, the insulation should not
obstruct the discharge opening.
Airflow Direction
The airflow direction through the gas heater is important
because it prevents localized “hot spots” on the heat
exchanger. Airflow direction labels denoting correct
airflow direction through the gas heat section are provided
on the burner side of the heating section. See
Figure 8
.
Figure 8.
Airflow direction label
Summary of Contents for CSA004
Page 24: ...24 CLCH SVX014B EN Wiring Diagrams Figure 12 Typical wiring diagram for 5 1 turndown heater ...
Page 25: ...Wiring Diagrams CLCH SVX014B EN 25 Figure 13 Typical wiring diagram for 10 1 turndown heater ...
Page 26: ...Wiring Diagrams 26 CLCH SVX014B EN Figure 14 Typical wiring diagram for 20 1 turndown heater ...