Cabinet Unit Heater
Contractor shall furnish and install Rittling Cabinet Unit Heaters as indicated on plans, with required
mounting components and accessories. Cabinet unit heaters shall be per the model and type
scheduled as manufactured by Zehnder Rittling under base bid. Cabinet Unit Heaters shall meet
types, sizes, capacities, and characteristics as scheduled on the Equipment Schedule or shown on
A. All units are CSA certified in the United States and Canada and comply with UL 1995 and CSA
C22.2 No. 236-95 requirements.
B. Coils shall be constructed of 1/2" OD seamless copper tube mechanically bonded to aluminum
fins. The entire coil assembly is factory tested to 350 PSIG air pressure when the coil is
submerged in water. It shall have a maximum working pressure of 300 psig. Coil connections
are 1/2". Each coil shall be supplied with a manual air vent. Optional high capacity or steam
C. Cabinets shall be of the type as shown on the drawings. Cabinets shall be manufactured from
18-gauge (14 and 16-gauge optional) cold rolled steel side panels. The front and top panels
shall also be furnished in 16-gauge (14-gauge optional) cold rolled steel.
D. End pockets shall be installed on both ends of the cabinet unit heater. Cabinets shall have 8"
end pockets on both sides of the internal cabinet for installation of electrical equipment or
control valves. End pockets maybe extended 6” each to provide more space.
E. Floor and wall non-recessed top panels shall be supplied with two flush, hinged access doors
with cam-lock fasteners. Recessed units front panels shall be supplied with two flush, hinged
access doors with cam-lock fasteners. Tamper-resistant fasteners available as an option.
F. Cabinet shall be provided with a standard ivory polyester urethane powder coating. Optional
colors can be selected from the Zehnder Rittling Color Chart.
G. Adjustable rear mounting brackets shall be supplied with all cabinets to provide necessary
adjustment to correct unit alignment during installation to untrue or non-square walls, studs,
joints and surfaces. Optional adjustable leveling legs (two on each base leg) shall be provided
where indicated on drawings or schedules (RF units only).
H. Recessed Units shall be provided with a wall seal assembly. The assembly shall provide a
finished appearance to the ceiling or wall.
I. Ceiling mounted or recessed units shall be supplied with a hinged front panel providing a 90°
swing. A standard safety chain prevents the face panel from accidentally swinging open. The
chain shall detach easily to allow uninhibited access for servicing.
J. Motors shall be permanent split capacitor, totally enclosed, tap wound for 3-speed, with
integral thermal overload protection for 120V/1Ph/60Hz. All motors feature a standard shaft
size of 1/2" diameter. Prior to shipping, all motors shall be assembled, factory tested and
installed in the unit. High static motors available for ducted applications.
K. Fan wheels shall be forward curved, tablock, centrifugal, and double-width galvanized steel.
All fan housings shall be constructed of galvanized steel.
L. Filters shall be provided as standard and shall be a one-inch disposable spun glass media with
foam and washable aluminum mesh filters optionally available.
M. Primary internal wiring and testing shall be conducted at the factory as standard. All units will
be shipped with wiring diagrams.
Zehnder Rittling · 100 Rittling Blvd · Buffalo, NY USA 14220
T 716-827-6510 · F 716-827-6523 · email@example.com · www.zehnder-rittling.com
N. Louvered inlet and outlets are standard on most units, with aluminum bar grille or perforations
available options. Duct collars and open inlet/outlets are available on select units.
O. Outside air intake dampers, available on RF units only, shall be provided where noted on
drawings and shall be:
1. 25% manual outside air dampers shall be provided where noted. A manually operated
damper quadrant shall provide 0% to 25% outside air through a single blade damper.
2. 25% motorized outside air dampers shall be provided where noted. A synchronous motor
interlocked with the blower shall open the outside air damper automatically when the
blower starts. The adjustable single blade damper shall provide 0% to 25% outside air. If
there is a loss of power or the blower stops, the damper shall return to a closed position.
A damper override switch can be provided to prevent damper operation.
P. Units shall be manufactured in accordance with conformance to ISO 9001:2000 standards.