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CAUTION
Appliances that are shut down or will not operate may experience freezing due to convective airflow in the air inlet pipe connected to the appliance.
The flue and air inlet duct sizes for a Horizontal
SIDEWALL COMBUSTION
AIR INLET
FIG. 32 Sidewall Vent Cap
The part numbers for the required sidewall air inlet and flue cap kit are listed by unit size. The manufacturer, in accordance with CSA requirements, must furnish both the sidewall air inlet and flue cap. Each kit includes the both the special combustion air inlet cap and the sidewall flue cap for installation on an exterior sidewall. The sidewall air inlet cap supplied in the kit is sized to provide combustion air for a single appliance only.
TABLE - J
|
| Flue |
| Air Inlet |
| Sidewall Air |
Input |
| Cap |
| Cap |
| Inlet & Flue |
Btu/hr |
| Size |
| Size |
| Cap Kit |
|
|
|
|
|
|
|
1,500,000 |
| 6" |
| 6" |
| HDK3018 |
___________ |
| _______ |
| _______ |
| ________________ |
1,700,000 |
| 7" |
| 8"* |
| HDK3019 |
___________ |
| _______ |
| _______ |
| ________________ |
2,000,000 |
| 8" |
| 8" |
| HDK3020 |
|
|
|
|
|
|
|
*Piping from the appliance to the air inlet cap may be either 7" or 8" connecting to an 8" sidewall cap provided in the kit.
Location of a Sidewall Air Inlet Cap
Installation, location and clearance requirements for the sidewall air inlet cap in an
FIG. 33 Air Inlet Cap for Sidewall Termination
The sidewall combustion air inlet cap and the rooftop flue gas outlet are located in different pressure zones in an
Combustion air supplied from outdoors must be free of contaminants (see Combustion and Ventilation Air). To prevent recirculation of flue products in to the combustion air inlet, follow all instructions in this and related sections.
Incorrect installation and/or location of the air inlet cap can allow the discharge of flue products to be drawn into the combustion process on the heater. This can result in incomplete combustion and potentially hazardous levels of carbon monoxide in the flue products. This will cause operational problems with the heater and possible spillage of flue products that can cause personal injury, death or property damage.
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