38
DES3
Series
3.0
Installation
•
Combustion Air Supply
•
Operational Unvented Operation
Figure 3.28
•
Minimum End Clearances
12 in. Min.
unvented
heaters
12 in. Min.
All heaters
When using an unvented configuration (commercial & industrial use only), consider the following:
• A factory vent cap/diffuser (P/N: WVE-GALV)
must be used.
• Where unvented heaters are used, natural or mechanical means
must be provided to
supply and exhaust a minimum of 4 cfm/1000 Btu/h input of installed heaters.
NOTE: Gravity or mechanical means may be used to accomplish the air displacement.
Local codes may require that the mechanical exhaust system be interlocked with the
electrical supply line to the heaters, enabling both to function simultaneously.
• The minimum clearance between the air intake and the exhaust terminal is 4 ft.
NOTE: When installing in a U-tube configuration, use extra caution to separate vent gases
from heater intake.
• Exhaust openings for removing the flue products must be located above the level of the
heater(s).
WARNING
!
Optional Unvented Operation
Not for residential use. The use of unvented tube heaters in residential indoor spaces
may result in property damage, serious injury or death. Use unvented operation in
commercial and industrial installations with proper ventilation rates only.
