Detroit Radiant Products Company HLV Series - Manual (Page 33)

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HLV Series 3.0 Installation • Combustion Air Requirements
Combustion Air Requirements
This heater has a factory preset air orifice to provide adequate combustion air intake to the unit.
Non-contaminated outside air for combustion must be ducted to the heater if any of the following apply:
• Chemicals such as chlorinated or fluorinated hydrocarbons are present in the space where the heater
is installed (typical sources are refrigerants, solvents, adhesives, degreasers, paints, paint removers,
lubricants, pesticides, etc.).
• Negative building pressure.
Indoor air supply: 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.
Outside air supply: Outside combustion air may be supplied via an accessory air duct attached directly
over the air orifice. A wall inlet cap (P/N: WIV) must be used with horizontal air intake ducts. It is
recommended that the air intake pipe is connected to the heater with a 4 in. diameter flexible air inlet boot
(P/N: AIRH) to allow flexibility for expansion (Figure 3.20). Sidewall (horizontal) air intake is preferred.
Refer to Chart 3.3 for limitations on the length and size of air intake ducts.
• A maximum of two elbows is allowed in the vent.
• Keep air intake opening a minimum of 4 ft. from any exhaust vent openings. Always place vent stacks
higher than air intake openings.
• An air intake cap (P/N: WIV) must be installed to prevent blockages. Locate intake cap in an area
where dirt, steam, snow, etc. Will not contaminate or clog the intake screen.
• Insulated duct or PVC pipe should be used in humid applications to prevent condensation on the outer
surface of the intake pipe.
Figure 3.20 • Outside Combustion Air Supply
Chart 3.3 • Combustion Air Intake Limitations
Duct Size Maximum Length
4 in. O.D. 30 ft.
5 in. O.D. 45 ft.
6 in. O.D. 75 ft.
Air Intake Cap
Burner Control Box
Air Inlet Boot
NOTE: A powered air inlet (P/N: V-PAI) can be used to bring in outside air for combustion for runs
exceeding 20 ft. up to a 150 ft. maximum run.