Living space with heater

Designer Riser Basic / DR-B

Williams

Designer Riser Basic / DR-B

Product Details

The Designer Riser Basic Vertical Stack (DR-B) is for concealed applications along walls and in corners. This model comes standard in an extended 97" galvanized steel cabinet, insulated with 1/2" thick neoprene coated fiberglass. Like the ER-B, this unit features a 1/2" OD copper tube coil, slide out blower assembly with quick disconnect plug, insulated drain pan and filter.

WARNING: This product can expose you to chemicals including epichlorohydrin which is known to the State of California to cause cancer and birth defects and/or other reproductive harm. For more information go to p65warnings.ca.gov

CUSTOMIZATIONS

CONSTRUCTION

All unit chassis shall be fabricated of heavy gauge cold-rolled steel cabinet painted in epoxy powder coated soft white paint. All exterior panels shall be insulated with 1/2″ thick, 1.5 pound per cubic foot, dual density fiberglass insulation rated for a maximum air velocity of 3600 f.p.m. Insulation shall conform to UL 181 for erosion and NFPA 90A and 90B for flame spread (25) and smoke developed (50) rating per UL 723 and CAN./ULC, S102-M88. and CAN./ULC, S102-M88.

Available Options:

  • Provide foil faced insulation in lieu of standard. Foil insulation shall meet or exceed the requirements stated above, and in addition, meet ASTM Standards C665 and C-1136 for biological growth in insulation. Insulation shall be lined with aluminum foil, fiberglass scrim reinforcement, and 30 pound kraft paper laminated together with a flame resistant adhesive. All exposed edges shall be sealed to prevent any fibers from reaching the air stream.
  • Provide elastomeric Elastomeric foam insulation in lieu of standard. Insulation shall conform to UL 181 for erosion and NFPA 90A for fire,smoke and melting, and comply with a 25/50 Flame Spread and Smoke Developed Index per ASTM E-84 or UL 723. Additionally, insulation shall comply with Antimicrobial performance rating of zero, no observed growth, per ASTM G21. Polyethylene insulation is not acceptable.

COILS

All cooling and heating coils shall optimize rows and fins per inch to meet the specified capacity. Coils shall have seamless copper tubes and shall be mechanically expanded to provide an efficient, permanent bond between the tube and fin. Fins shall have high efficiency aluminum surface optimized for heat transfer, air pressure drop and carryover.

All coils shall be hydrostatically tested at 350 PSIG air pressure under water, and rated for a maximum of 300 PSIG working pressure at 180°F maximum water temperature. Direct expansion cooling coils shall include a fixed orifice distributor and nozzle.

Steam coils shall be standard steam type suitable for temperatures above 35°F and 15 PSIG maximum working pressure.

Available Options:

  • Coil casing shall be fabricated from 304 stainless steel.
  • Provide a manual air vent fitting to allow for coil venting.
  • Provide a manual water drain fitting for coil draining.
  • Provide automatic air vents in lieu of manual air vents.
  • Cooling and heating coils shall be in the common coil casing, heating coils shall be furnished in the re-heat or preheat position on the unit with chilled water coils, and DX coil shall be in preheat position only.

DRAIN PANS

Condensate drain pan shall be single wall, heavy gauge, powder coated epoxy and extend under the entire cooling coil. Drain pan shall be of one piece construction and be positively sloped for condensate removal. Drain pan shall have a single drain connection.

The drain pan shall be externally insulated with a closed cell foam insulation. The insulation shall carry no more than a 25/50 Flame Spread and Smoke Developed Rating per ASTM E-84 and UL 723 and fungi resistant per ASTM G21/C1338, bacteria resistant per ASTM G22 and mold growth per UL 181.

Available Options:

  • Provide a single wall primary drain pan constructed entirely of heavy gauge type 304 stainless steel for superior corrosion resistance. Stainless steel drain pans shall be externally insulated and meet or exceed the requirements stated above.

ELECTRIC HEAT

Furnish an electric resistance heating assembly as an integral part of the fan coil unit, with the heating capacity, voltage and kilowatts scheduled. The heater assembly shall be designed and rated for installation on the fan coil unit without the use of duct extensions or transitions, and be located in the unit as to not expose the fan assembly to excessive leaving air temperatures that could affect motor performance.

The heater and unit assembly shall be listed for zero clearance and meet all NEC requirements, and be UL listed with the unit as an assembly in compliance with UL/ANSI Standard 1995.

All heating elements shall be open coil type Nichrome wire mounted in ceramic insulators and located in an insulated heavy gauge galvanized steel housing. All elements shall terminate in a machine staked stainless steel terminal secured with stainless steel hardware for corrosion resistance. The element support brackets shall be spaced no greater than 3-1/2” on center. All internal wiring shall be rated for 105°C minimum. All heaters shall include over temperature protection consisting of an automatic reset primary thermal limit and back up secondary thermal limit. All heaters shall be single stage. An incoming line power distribution block shall be provided and designated to accept single point power wiring capable of carrying 125% of the calculated load current.

PIPING PACKAGES

Provide a factory assembled valve piping package to consist of a 2 or 3 way valve body, on/off motorized electric control valve actuator and two isolation ball valves. Control valves are piped normally closed to the coil. Maximum entering water temperature on the control valve is 180°F, and maximum close off pressure is 75 PSIG (1/2″) or 44 PSIG (3/4″). Maximum allowed pressure shall be 300 PSIG.

Available Options:

  • Provide 3 wire floating point modulating control valve in lieu of standard 2 position control valve with factory assembled valve piping package.
  • Provide either a fixed or adjustable flow control device for each piping package.
  • Provide pressure temperature ports for each piping package.
  • Strainer for each package. Piping packages are shipped loose on all units and can be installed by request only.

ELECTRICAL

Units shall be furnished with a J-Box wrapper, wired for signel point power connection

Available Options:

  • Electrical junction box with multiple position ¼” spade terminal block to facilitate wiring terminations for the electric control valves
    an thermostats.
  • With Electric Heat, unit may be shipped loose or integrated.
  • Include fusing, disconnects, sensors and switches.

FILTERS

All units shall be furnished with a one inch thick, throwaway filter, flatly mounted with spring loaded clips on the front of the coil for easy maintenance without the use of tools.

Available Options:

  • Washable filters.