Sterling Convectors: Steam and Hot Water Radiation

Key Features and Components

Heating Elements: Available in nominal depths of 4" (2-tube), 6" (3-tube), and 8" (4-tube). Fins are made of .010" aluminum with integral collars for uniform spacing. Tubes are mechanically expanded into collars for optimal heat transfer. Headers are cast bronze with single 3/4" NPT tappings; a dual top/bottom 3/4" tapped header option is available for flexible piping connections.

End Pockets: Optional at either end to protect and conceal valves, traps, and piping. They extend the liner and cabinet front, with a baffle welded to the liner's back. Length is determined by the standard element size. Available in 4" increments; one end pocket is standard on 64" units. Note: Fronts and liners increase in length, but coil length remains standard.

Access Doors: 4 1/4" square doors can be provided in the front panel for access to valves, traps, or air vents. They are hinged at the top and secured with a concealed 1/4 turn locking device operated by an Allen-head tool. Availability of all positions may vary for units 24" or less in height.

Enclosures: Formed from steel, typically 18-gauge for fronts and 20-gauge for backs and sides. Enclosure fronts attach to the unit liner via friction-fit slip joiners. Back, top, and sides are usually an integral welded structure, except for wall-hung slope-top models.

Dampers: Factory-installed, knob-operated dampers are available, featuring a triple lead screw for easy adjustment. Tamper-resistant operators (hex key) are also an option, ideal for institutional settings.

Fasteners: Standard friction-fit slip joiners are used. Tamper-resistant fasteners with Hex Head Locks are available for special applications. Concealed fasteners with a Hex-head operator are also offered.

Insulation: 1/2" thick fiberglass insulation is available for convector backs, sides, and tops upon special request.

Finishes: All convectors receive a high-quality baked powder prime finish. Custom colors are available.

Heavy Gauge Steel: Institutional convectors can be specified with heavier gauge steel (18, 16, or 14-gauge) for fronts and backs to withstand demanding applications.

Non-Standard Sizes: Custom sizes can be provided for specific institutional requirements.

Perforated Outlets/Inlets: Available for styles with 14-gauge perforated front panels.

Types of Convectors

Sterling offers a variety of convector types designed for different installation needs:

• FS-A / FSG-A (Free-Standing): Designed for exposed installation, fitted flush against the wall. Ideal for modernization projects. FS-A has an open inlet; FSG-A has a louvered inlet.
• W-A (Wall Hung, Flat Top): Fully exposed wall-hung unit with a flat top and louvered outlet. The enclosure wraps around the unit and fastens with clips. Air inlet is through the open bottom.
• SW-A (Wall Hung, Slope Top): Fully exposed wall-hung unit with louvers in a sloping top (30° slope). Air inlet is through the open bottom.
• SR-A / SRG-A (Semi-Recessed): Projects only 2 1/4" from the wall. Enclosure front attaches to brackets on a wall-recessed liner. SR-A has an open inlet; SRG-A has a louvered inlet.
• PW-A / PWG-A (Partially Recessed): Features a rounded flange front and louvered outlet, extending 2 1/4" from the wall. Enclosure front fastens to a recessed liner. PW-A has a bottom inlet; PWG-A has a louvered inlet.
• RF-A / RFG-A / FWG-A (Fully Recessed): Designed for full recess within the wall. The metal front contains both outlet and inlet openings and is secured by screws for easy element access. RF-A has an open inlet; RFG-A and FWG-A have louvered inlets. FWG-A is specifically for wall mounting.

Technical Data and Selection

The catalog provides extensive tables for steam and hot water ratings, correction factors, and pressure loss data. These tables are crucial for selecting the appropriate convector model based on heating load, water temperature, steam pressure, and flow rates.

Steam Ratings (Tables 1, 1A, 2, 2A): These tables list BTU/H ratings for various convector types (FS-A, FSG-A, W-A, SW-A, SR-A, SRG-A, PW-A, PWG-A, RF-A, RFG-A, FWG-A) across different depths, lengths, and liner heights, based on standard conditions (215°F steam, 65°F EAT).

Hot Water Capacities (Tables on pages 8-12): Similar to steam ratings, these tables provide BTU/H capacities for hot water systems, detailing performance based on Average Water Temperature (AWT) and Entering Air Temperature (EAT).

Correction Factors (Tables 3, 4):

• Table 3: Convector Correction Factors based on Average Water Temperature and Entering Air Temperature. These factors are used to adjust ratings for conditions other than the standard ones listed.
• Table 4: Correction Factors for Steam Pressures other than 1 PSI Gauge. These factors are applied to steam ratings to account for different operating pressures.

Pressure Loss (Table 5): Details pressure loss in feet of water for different convector sizes (4", 6", 8" models) at various water flow rates (GPM). This data is essential for pump head calculations.

Access Door Correction Factors (Table 5): Provides factors to adjust ratings when access doors are specified, depending on the convector type and length.

Capacity and Selection Data (Tables 7, 8):

• Table 7: Illustrates the relationship between Gallons Per Minute (GPM) of hot water required and the heating load (MBH) for different temperature drops (10°F, 20°F, 30°F, 40°F).
• Table 8: Lists Output-Flow Rate Corrections, showing minimum MBH requirements for turbulent flow at specific water temperature drops and minimum flow rates. This table is used to ensure proper system performance.

The document also includes guidance on using glycol solutions in heating systems, providing correction factors for heat transfer, GPM requirements, pump head, and freezing points.

Design and Installation Details

Detailed diagrams and specifications are provided for each convector type, illustrating dimensions, mounting options, and component layouts. These include:

• Model Designation: Tables specify models by depth (D), length (L), height (H), and other dimensions (B, J) for each convector type (FS-A/FSG-A, W-A, SW-A, SR-A/SRG-A, PW-A/PWG-A, RF-A/RFG-A, FWG-A).
• Dimensional Drawings: Exploded views and side profiles show typical installation configurations, including wall mounting, recessing, and component placement (damper, piping connections).
• Heating Element Construction: Details the non-ferrous construction with aluminum fins bonded to copper tubes, cast bronze headers, and optional dual inlet headers.
• System Piping: Diagrams illustrate typical piping arrangements for both hot water and steam systems, showing supply and return lines, vent plugs, and traps.

General Specifications

Convector Radiators: Shall be furnished and installed as shown on plans.

Heating Elements: Non-ferrous, 3/8" copper tubing with .010" aluminum fins, mechanically bonded. Tested at 100 PSI air pressure. Supported by brackets for proper pitching.

Cabinets: Formed from cold-rolled steel, braced for stiffness, and fitted to prevent air leakage. Louvers are typically Venetian type. All cabinets receive a high-quality baked powder prime finish.

Institutional Cabinets: Feature tamper-resistant fasteners and operators for dampers and access doors.

Optional Equipment: Includes knob-operated dampers, access doors, and optional knock-outs on cabinet sides.

Unit Size Selection: Guidance is provided on how to select the correct convector size based on MBH capacity, water temperature, and temperature drop, referencing the rating tables.

Contact Information

For assistance with ratings and selection, Sterling recommends using their online Specifier. Additional product information and support are available:

Sterling Commercial Hydronic Products
260 North Elm Street, Westfield MA 01085
Tel: (413) 564-5535
www.sterlingheat.com
A Mestek Company