QMARK CU900 Series Custom Cabinet Unit Heaters - Submittal Sheet
Manufacturer: QMARK (A Marley Engineered Products Brand)
Address: 470 Beauty Spot Rd. E, Bennettsville, SC 29512
Website: QMarkMEP.com
Certifications: UL/cUL Listed
Product Overview
The QMARK CU900 Series offers custom cabinet unit heaters designed for commercial and industrial applications. These heaters are built with heavy-duty cold-rolled steel and are UL/cUL Listed, suitable for mounting in various positions including on-end, fully recessed, semi-recessed, or surface mounted.
Key features include a robust cabinet, efficient heating elements, quiet motor and blower assembly, and integrated safety features like thermal cutouts and front cover interlocks.
Capacities: 2-32 KW
Voltages: 208, 240, 277, 347, 380, 480, or 600V
Phase: 1 or 3 Phase
Temperature Range: 55°-85° F
Air Movement: 500-2000 CFM
(Image description: A front view of a QMARK CU900 Series unit heater, showing a white rectangular cabinet with a grille on the front.)
Architect's and Engineer's Specifications
The electric cabinet unit heaters are manufactured by QMark, a Marley Engineered Products Brand. They are UL/cUL Listed and designed for flexible mounting. Control voltage is typically 24 VAC, with an optional 120 VAC.
Cabinet
Constructed from heavy-duty cold-rolled steel, with front covers secured by spring latches (optional key lock). Available in Beige polyester powder coating, with other colors optional.
Heating Elements
Warranted for five years, featuring non-glowing 80/20 NiCr resistance wire with steel plate fins brazed to a steel sheath. Elements are positioned directly in front of the blower discharge for uniform heating.
Safety Features
Includes built-in thermal safety cutouts that automatically shut off the heater in case of overheating. An optional manual reset thermal cutout is available. A front cover interlock de-energizes the heater when the cover is removed.
Motor and Blower Assembly
Direct drive, resiliently mounted, two-speed 1/8 HP motors with automatic reset overload protection. Motors are mounted in the airstream for cooling. Forward-curved, double-inlet centrifugal blowers ensure uniform discharge air temperatures.
Air Filters
Located ahead of the motor and blower, filters can be either standard disposable or optional permanent washable types. They are accessible by removing the front panel.
Controls
Features include fan delay control, built-in single-stage thermostat (with options for two-stage or remote thermostats), and terminals for Building Automation/Energy Management Systems. Heat selection and fan speed are controlled by a rocker switch. Circuit breakers are standard for heaters over 48 amps and optional for others.
Louvers
Intake and discharge louvers are interchangeable, allowing for front-to-bottom or front-to-top configuration changes with minimal effort.
Optional Equipment
Factory or field-installed options include manual reset thermal cutouts, circuit breakers, dead front disconnect switches, on/off switches, duct collars, washable filters, recess trim kits, space base kits, and aluminum wall louvers.
Custom Cabinet Unit Heaters: Models and Specifications
| Series | KW | BTU/HR | FINAL AIR TEMP (°F) | CFM* | AMPERAGE (Volts / Phase) | SHIP WT. | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 208 / 1 | 208 / 3 | 240 / 1 | 240 / 3 | 277 / 1 | 480 / 3 | ||||||
| CU935 (35 in. L) | 2 | 6,826 | 85° F | 500 | 10 | 6 | 9 | 6 | 8 | 3 | 120 lbs |
| 3 | 10,239 | 98° F | 15 | 9 | 13 | 8 | 12 | 4 | |||
| 4 | 13,652 | 111° F | 20 | 12 | 17 | 10 | 15 | 6 | |||
| 5 | 17,065 | 123° F | 25 | 15 | 22 | 13 | 19 | 7 | |||
| 6 | 20,478 | 136° F | 30 | 17 | 26 | 15 | 22 | 8 | |||
| 7 | 23,891 | 148° F | 34 | 20 | 30 | 18 | 26 | 9 | |||
| 8 | 27,304 | 161° F | 39 | 23 | 34 | 20 | 30 | 10 | |||
| CU945 (45 in. L) | 4 | 13,652 | 85° F | 1,000 | 20 | 12 | 18 | 11 | 16 | 6 | 160 lbs |
| 6 | 20,478 | 98° F | 30 | 18 | 26 | 16 | 23 | 8 | |||
| 8 | 27,304 | 111° F | 40 | 23 | 34 | 20 | 30 | 11 | |||
| 10 | 34,130 | 123° F | 48 | 29 | 43 | 25 | 37 | 13 | |||
| 12 | 40,956 | 136° F | 59 | 34 | 51 | 30 | 44 | 16 | |||
| 14 | 47,782 | 148° F | 68 | 40 | 59 | 35 | 52 | 18 | |||
| 16 | 54,608 | 161° F | 78 | 46 | 68 | 40 | 59 | 20 | |||
| CU968 (68 in. L) | 15 | 51,195 | 123° F | 1,500 | -- | 44 | -- | 38 | -- | 20 | 260 lbs |
| 21 | 71,673 | 148° F | -- | 60 | -- | 52 | -- | 27 | |||
| 24 | 81,912 | 161° F | -- | 69 | -- | 60 | -- | 31 | |||
| CU978 (78 in. L) | 20 | 68,260 | 123° F | 2,000 | -- | 58 | -- | 50 | -- | 26 | 300 lbs |
| 24 | 81,912 | 136° F | -- | 69 | -- | 60 | -- | 31 | |||
| 28 | 95,564 | 148° F | -- | 80 | -- | 70 | -- | 36 | |||
| 32 | 109,216 | 161° F | -- | 91 | -- | 79 | -- | 41 | |||
NOTE: BOLD numbers represent circuit breakers or fused disconnect required. **380V units will operate with a 16% reduction in heating capacity. +Based on 60°F inlet air temperature. *Values shown are for high speed. All models operate at 60Hz.
Optional Accessories
Factory-Installed Accessories
| Accessory | Description | Standard | Optional | Ship Wt. |
|---|---|---|---|---|
| 2-Stage Thermostat (Built-in or Remote) | Single-pole, single-stage thermostat cycles elements and fan. Fan speed and wattage selected by HIGH/LOW switch. | Built-in (or remote-mounted) single-pole, single-stage thermostat that cycles the element(s) and fan. Fan speed and element wattage selected by the built-in HIGH or LOW selector switch. | Built-in (or remote-mounted) two-stage thermostat that cycles 2/3 of the element for during first stage and full heat during second stage. Fan cycles on high speed only. | - |
| Smartseries Plus (Built-In or Remote) | Two-stage thermostat, BACnet BMS compatibility, scheduling, cooling mode (Fan-Only), keypad lock. | Built-in (or remote mounted) two stage thermostat runs 2/3 elements on stage 1 and full heat for stage 2. Fan cycles on high speed only. Comes with BACnet BMS compatibility, scheduling, cooling mode(Fan-Only), and keypad lock. | - | - |
| Dead Front Disconnect Switch | Three-pole, non-fused disconnect switch. Prevents compartment entry until switch is OFF. | A three pole non-fused disconnect switch disconnects power to the heater. Design prevents entry into the control compartment until disconnect switch is turned to the OFF position. | Supply terminal block in the control compartment. | - |
| Dead Front Fused Disconnect Switch | Three-pole, non-fused disconnect switch and circuit breaker(s) sized to load. Protects heater and disconnects power. | A three pole non-fused disconnect switch and circuit breaker(s) sized to the heater load protects heater and disconnects power to the heater. | Supply terminal block in the control compartment. | - |
| On/Off Switch | No switch supplied. | - | Built-in switch provides continuous fan operation with or without heat, or automatic fan cycling as the heat cycles on and off. | - |
| Key Lock For Front Cover | Two (2) slotted head spring latches. | Two (2) slotted head spring latches. | Two (2) toolhead key lock style spring latches prevent unauthorized adjustment of controls and provide additional safety. | - |
| Inlet or Discharge Duct Collar(s) | Standard Architectural Grilles. | Standard Architectural Grilles. | Collars provide easy connection of field supplied duct work. Heater with duct collars supplied with single speed high static motor. (Do not exceed 0.2 in. wg external static pressure). | - |
| Louver Grilles | Standard Architectural Grille. | Standard Architectural Grille. | Retrofit option for old louver design. Available for both inlet and discharge openings ordered together. | - |
Field-Installed Optional Equipment
| Catalog No. | Description | Compatible With | Function | Ship Wt. |
|---|---|---|---|---|
| CU935RTK* | Recess Trim Kit | CU935, CU945, CU968, CU978 | Provides a neat finish to semi-recessed or full recessed application. | 3 lbs |
| CU945RTK* | 4 lbs | |||
| CU968RTK* | 6 lbs | |||
| CU978RTK* | 7 lbs | |||
| CU935BK* | Space Base Kit | CU935, CU945, CU968, CU978 | 16 gauge, muted black base recessed from heater front/sides for attractive, practical floor mounting. | 9 lbs |
| CU945BK* | 10 lbs | |||
| CU968BK* | 13 lbs | |||
| CU978BK* | 15 lbs | |||
| CU935WF | Permanent, Reusable Washable Filter | CU935, CU945, CU968, CU978 | Replaces standard filter. Washable filter can be cleaned and replaced. | 4 lbs |
| CU945WF | 6 lbs | |||
| CU968WF | 10 lbs | |||
| CU978WF | 12 lbs |
*Add appropriate color code suffix (e.g., W for White, B for Black).
Dimensions and Clearances
Dimensions:
Unit heights vary by model, with common dimensions being 26-3/8" height x 9-3/4" deep. Lengths vary by model: 35", 45", 68", 78".
(Diagram description: A side view of a unit heater showing dimensions. Key dimensions indicated are 9-3/4" depth, 26-3/8" height, and various lengths for different models. Also shows concentric knockouts for electrical connections and a conduit hole location.)
Clearances:
- Heater Wall Mounted:
- Front Discharge: No obstruction within 24" of discharge.
- Top Discharge: No obstruction within 24" of discharge.
- Front Intake: Zero or greater to base of heater.
- Bottom Intake: No obstruction within 24" of discharge.
- Heater Ceiling Mounted:
- Front Discharge: No obstruction within 24" of discharge.
- Top Discharge: No obstruction within 24" of discharge.
- Front Intake: Zero or greater to base of heater.
- Bottom Intake: No obstruction within 24" of discharge.
- Minimum 2" to side wall.
Multiple Air Flow Combinations:
The CU900 Series offers various air flow configurations:
- Front Inlet, Front Outlet (FIFO)
- Front Inlet, Top Outlet (FITO)
- Bottom Inlet, Front Outlet (BIFO)
- Bottom Inlet, Top Outlet (BITO)
- Wall Mounted
- Inverted
- On End
(Diagram description: A series of illustrations showing different mounting and air flow configurations: Wall mounted, Inverted, On End, Front Inlet/Front Outlet, Front Inlet/Top Outlet, Bottom Inlet/Front Outlet, Bottom Inlet/Top Outlet.)
Key Features
- Attractive cabinet enclosure designed for commercial areas.
- Mounting flexibility: ceiling, floor, or wall; surface, full recess, or semi-recess.
- Heavy-duty cold-rolled steel construction.
- Nineteen capacities from 2kW to 32kW; five cabinet lengths (35", 45", 68", 78").
- Two-speed 1/8 HP PSC motors with automatic thermal overload protection.
- Steel plate fin elements with copper brazing, finished with aluminized paint for corrosion resistance.
- Thermal safety cutout for automatic shut-off during overheating.
- Optional manual reset thermal safety cutout.
- Circuit breaker protection for heaters over 48 amps; optional for others.
- Built-in single-pole, snap-action thermostat with remote bulb sensor.
- 24-volt control system with prewired transformer.
- Tamper-resistant, two-position selector switch for heat and fan speed.
- Automatic fan delay for eliminating cold drafts and dissipating residual heat.
- Silent relays instead of conventional contactors.
- Optional aluminum wall louver for finished exterior.
- Optional UL-listed inlet and discharge duct collars.
- Standard throw-away air filter; optional permanent washable filters available.
- Front cover interlock for safety.
- Optional dead front disconnect switch or fused disconnect switch.
- Optional built-in on/off switch.
- Optional trim kits and space base kits for installation aesthetics.
How to Order
The ordering process involves selecting various options using a coded system. An example order code is provided:
Example: CU 9 35 10 24 1 F F 1B 0 0 S O P K P B
Breakdown of Order Code Components:
- Catalog Prefix: CU = QMark
- Series: 9 (CU900 Series)
- Length: 35 = 35", 45 = 45", 68 = 68", 78 = 78"
- KW: 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 14, 15, 16, 18, 20, 21, 24, 28, 32
- Voltage: 20 = 208V, 24 = 240V, 27 = 277V, 34 = 347V, 48 = 480V, 60 = 600V
- Phase: 1 = 1Ø, 3 = 3Ø
- Inlet Configuration: F = Front, B = Bottom
- Outlet Configuration: F = Front, T = Top
- Thermostat: 1B = Single Stage Built In, 1R = Single Stage Remote Wall Mount, 2B = Two Stage Built In, 2R = Two Stage Remote Wall Mount, SB = SmartSeries Built In, SR = SmartSeries Remote
- Control Voltage: 2 = 24VAC
- Cabinet Finish: A = Aluminum, B = Black, G = Charcoal Grey, N = Beige, W = White, S = Statuary Bronze, U = Special Color Request
- Duct Collar/Grille: 0 = Standard Inlet/Standard Discharge, I = Duct Inlet/Standard Discharge, D = Standard Inlet/Duct Discharge, B = Duct Inlet/Duct Discharge, L = Louvre Inlet/Louvre Outlet, M = Duct Inlet/Louvre Discharge, N = Louvre Inlet/Duct Discharge, A = Architectural Inlet/Architectural Discharge, F = Architectural Inlet/Standard Discharge, G = Architectural Inlet/Duct Discharge (*Standard = Wrigley)
- Front Cover Lock: 0 = Std. Lock, K = Key Lock
- Air Intake Filter: 0 = Std. Throw-Away, P = Permanent Washable
- On/Off Switch: S = Heat On/Off Switch, 0 = None, 0 = N/A-SmartSeries Controls
- Disconnect Switch: S = Disconnect Switch, F = Fused Circuit Breaker Disconnect, 0 = None
- Circuit Breaker: C = Circuit Breaker, 0 = None
Important Notes:
- Manual Reset is now standard on all CU units.
- Summer Fan Switch is now ordered via Digital Controls.
- Night Set Back is now ordered via Digital Controls.
- Outside Air Damper is no longer offered.
- Colors are monochrome unless special request.
- Consult Marley Sales Representative for specific configuration needs.
