Optional Unvented Operation; Combustion Air Requirements - Re-Verber-Ray LD Series Installation Manual

3.0 Installation
•

Optional Unvented Operation

Optional Unvented Operation
This appliance must be vented in residential installations. Unvented tube heaters in
residential spaces may result in property damage, serious injury or death. Use unvented
operation in commercial and industrial installations with proper ventilation rates only.
When using an unvented configuration
• A factory vent cap/diffuser (P/N: WVE-3) 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).
• Use of combustion air intake.
Figure 3.25 • Minimum End Clearances
12 in. Min.
All heaters

Combustion Air Requirements

Combustion air may be supplied to the heater by indoor or outdoor means.
If using combustion air from indoors, the required volume of the space must be a minimum of 50 ft
1000 Btu/hr unless the building is of unusually tight construction. If the building is of unusually tight
construction with air infiltration rates of less than 0.40 air changes per hour, outside combustion air is
typically needed unless the sheer size of the building allows otherwise. Contact the factory for further
determination of air infiltration rates.
• Combustion Air Requirements
WARNING
!
(commercial & industrial use only)
28
LD
, consider the following:
12 in. Min.
Series
unvented
heaters
per
3