Detroit Radiant Products Company DES3 Series - Manual (Page 28)

28
When using an unvented configuration, consider the following:
• A factory supplied vent cap/diffuser (P/N: WVE-GALV) must be used.
• Where unvented heaters are used, natural or mechanical means must be provided to supply
adequate ventilation - a minimum of 4 cfm/1000 BTU/h (0.38 m 3 /kW) 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: Maintain a
36” minimum distance from vent to combustion air intake on heaters fitted with a U-bend
accessory fitting.
• Exhaust openings for removing the flue products must be located above the level of the heater(s).
• Use of combustion air intake.
3.0 Installation • Optional Unvented Operation • Combustion Air Requirements
WARNING
!
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.
Optional Unvented Operation
Figure 3.26 • Minimum End Clearances
12 in. Min.
Combustion Air Requirements
Combustion air may be supplied to the heater by indoor or outdoor means.
If using combustion air intake from indoors, the required volume of the space must be a minimum of 50 ft 3
per 1000 BTU/h (4.8 m 3 /kW) 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.
unvented
heaters
12 in. Min.
All heaters