Engineering Specs
5   
the set operating temperature by 9F° (5C°) when area lighting level is reduced due to an 
unoccupied condition. 
a.  The thermostat will be comprised of a metal dome that will attach to a mounting plate 
using two metal screws. All control circuitry and comfort temperature selection controls 
will be mounted inside of the metal dome enclosure to protect the circuitry and provide 
resistance to tampering with temperature settings. 
i.  Optionally tamper proof screws for mounting of the metal dome to the mounting 
plate will limit access to thermostat settings to authorized personnel with access 
to the special tool required to manipulate the screws 
b.  The thermostat will sense both infrared and ambient temperature and average the two to 
maintain the comfort temperature setting within the heat zone 
c.  The thermostat will incorporate automatic temperature setback of 9F° (5C°) during an 
unoccupied condition. A photoconductive cell will be used to sense occupancy within the 
heater zone by sensing illumination. Resumption of the occupied state illumination level 
will return thermostat temperature control to full comfort setting. A switching mechanism 
will allow calibration of the photoconductive cell to the base illumination level for occupied 
status. A switching mechanism within the thermostat will allow for disabling of the 
temperature setback feature. 
d.  The thermostat mounting plate will attach to a standard 4” x 4” octagonal electrical box. 
e.  Electrical rating: 24 Vac, 60Hz 
4.02  Other Heater Ancillaries 
A.  Gas Connection 
i.  USA: Each heater will be connected to the gas supply piping using a CSA International 
certified stainless steel flexible gas connector sized according to heater input and as 
supplied by the manufacturer of the heater. 
ii.  Canada: Each heater will be connected to the gas supply piping using a CSA 
International certified Type-1 Hose gas connector sized according to heater input and 
as supplied by the manufacturer of the heater. 
B.  Combustion Air intake: 
When located in an area with a negative air condition or a dust laden environment the 
heater will be fitted with a 4 inch (100 mm) or 5 inch (127 mm) diameter duct as described 
in the Installation and Owner’s Manual. The duct termination will be fitted with an optional 
cap as supplied by the manufacturer 
C.  Modular 90° Elbow Kit: 
To enable a 90° bend in the tube system, the heater will be fitted with a 90° elbow kit 
complete with aluminized steel elbow, wire hanger, tube coupler, and aluminized steel 
reflector cap as supplied by the manufacturer. The elbow kit will be modular in design to 
enable a 180° bend in the system by installation of two adjoining 90° elbow kits. Elbow kit 
will be installed in the system as per the Installation and Owner’s Manual provided by the 
manufacturer, noting in particular minimum length location from the burner. 
D.  Reflector Extension 
To prevent impingement of infrared heat on nearby surface(s) the heater will be fitted with a 
reflector extension as supplied by the manufacturer of the heater. The reflector extension 
will be installed on the heater(s) as per the manufacturer’s instruction and as indicated on 
the drawings. 
Copyright 2021 Rinnai America Corporation. Rinnai® is a registered trademark of Rinnai Corporation used 
under license by Rinnai America Corporation. Rinnai America Corporation continually updates materials, 
and as such, content is subject to change without notice. 
900000038 
3/2021 





