35
1. Direct to outdoors
2.
3.
Horizontal ducts
4.
5. From a larger room inside the house (not recommended – refer to "Calculate the air volume of the room"
above to determine if the combined volume of the rooms may be adequate).
Determine minimum free area required for each vent opening
from “Before beginning”) and the type of vent used.
Table 1
provides the minimum free area for each vent opening
Calculate the air volume of the room
Air requirements depend on the size of the room.
3
2
If there are large objects in the room (e.g., refrigerator, furnace, car), subtract their volume from the vol-
Air Volume = Room Volume - Object Volume
Calculate required air volume
feet per 1,000 BTU/h of the total input for all gas burning appliances in the same area.
3
3
/ 1000 (btu/h)
Example:
(235,000 / 1000) x 50 = 11,750
If the air volume of the room is less than the required air volume, you must direct vent the water heater
-
If the air volume of the room is greater than the required air volume, it may be possible to install the
as furnaces, whole house fans, and clothes dryers draw air out of your home. If they draw air out faster
-
Install with outside ven
til
a
tion
Supplying outside air to the boiler typically requires two openings. One opening must be within 12
opening is not preferred, you may use a single opening to outside air if the minimum free area is sized accord-
ing to
Table 1
Determine type of ven
til
a
tion
A boiler installed in an unconfined attic, garage, or space requires that the space be at least 50 cubic
boiler
boiler
boiler
boiler
Summary of Contents for Smart 115 PLUS
Page 49: ...49 Boiler Notes ...
