User Guide

Infrared Heater Selection Procedure – Additional Selection Considerations
9-200.6 9
Figure 9.1 – Layout for Example 2
Additional Considerations (All Applications)
The selection process described for Spot, Partial Area, and
Total Building Heating applications, while seemingly simple,
does not consider all variables in the design and layout of the
infrared heating solution. The following provides additional
background information on factors to be considered when
designing the solution. Guidelines and limitations stated in the
Installation and Service Manuals must also be followed.
Mounting Height/Building Obstructions
 For lower mounting heights, use a larger number of
closely spaced units with lower input ratings.
 For high mounting heights, use a smaller number of units
with higher input ratings spaced further apart.
 Building obstructions such as overhead cranes, lighting,
and utilities must be avoided.
Low-Intensity Tube Length Considerations
 Units with higher input ratings are certified for longer tube
lengths while units with lower input ratings are certified for
shorter tube lengths. Please see the Performance Data
for additional information.
 A layout as uniform as possible should be used, however
some areas may be exceptions, such as placing higher
ratings or a higher number of units with short tube lengths
where heat loss is greater. Examples include a Northern
facing wall with a prevailing wind or a frequently opened
overhead door.
Clearances to Combustibles and Heat-Affected Objects
 Clearances to combustible materials must be maintained,
including areas with stored or stacked materials. See
pages 4 and 5 for additional information.
 Clearance to heat affected objects such as sprinkler
heads must be considered. Generally, high intensity
units or the burner and first tube section of the low-
intensity units should be kept at least 6-8 feet from the
sprinkler head, assuming the sprinkler head is not in the
direct path of infrared radiant energy.
Availability of Utilities (Gas and Electric)
 Availability of gas and electric should be considered. If
electric service is difficult or costly to extend, high-
intensity units with millivolt controls are an excellent
choice as external electrical power is not required.
 As shown in the figure for Example 2, multiple units can
be positioned end-to-end for common venting, and to
reduce the amount of gas piping and electricity wiring
required. This is often a trade-off with optimizing the
coverage area, which is usually end-to-front positioning.
Venting/Ventilation
 High-intensity units require a minimum positive air
displacement of 4 CFM per 1000 Btu/hr input for natural
gas or 5 CFM per 1000 Btu/hr input for propane gas.
Please see the Installation and Service Manuals for
additional information and requirements.
 For unvented units, it is important that the building have
adequate insulation, especially the ceiling. The products
of combustion, which contain a great deal of moisture, will
rise in the building. When these moist gases come in
contact with the cold building surfaces, considerable
condensation can occur. This moisture can cause a
great deal of damage and possibly cause safety hazards,
such as water leaking onto the floor causing slippery
conditions.
 For low-intensity units, limitations on the length of flue
pipe allowed for different ratings and tube system lengths
exist. These limitations can be found in the Installation
and Service Manuals.
 Low intensity units can be common vented in pairs out a
single larger vent to reduce the number of building
penetrations for venting and therefore installed cost.
Units must be of identical burner input rating and tube
system length and must be controlled by a single
thermostat. Please refer to the heater Installation and
Service Manual and the National Fuel Gas Code
Handbook for additional information and requirements.
Figure 9.2 – Typical Common Venting