SECTION 15821

SPRAYED COIL DEHUMIDIFIERS

PART 1 GENERAL

SECTION INCLUDES

Sprayed coil dehumidifier units.

Spray pumps.

Insulation.

PRODUCTS FURNISHED BUT NOT INSTALLED UNDER THIS SECTION

Section 15540 - HVAC Pumps: Placement of spray pumps.

PRODUCTS INSTALLED BUT NOT FURNISHED UNDER THIS SECTION

Section 15545 - Chemical (Water) Treatment: Supply of solenoid valves for placement by this Section.

Section 15952 - Controls and Instrumentation: Placement of control valves.

RELATED SECTIONS

Section 15252 - Piping and Equipment Insulation: Insulation of external piping.

Section 15290 - Ductwork Insulation: Insulation of casing.

Section 15510 - Hydronic Piping: Connection to chilled water system.

Section 15535 - Refrigeration Piping and Specialties: Connection to refrigeration system.

Section 15540 - HVAC Pumps: Spray pumps.

Section 15790 - Air Coils.

Section 15855 - Air Handling Units with Coils: Dimensional match.

Section 15952 - Controls and Instrumentation.

REFERENCES

ANSI/ARI 410 - Forced-Circulation Air-Cooling and Air-Heating Coils.

SMACNA - HVAC Duct Construction Standards, Metal and Flexible.

SUBMITTALS

Submit shop drawings under provisions of Section [01300.] [_____.]

Shop Drawings: Indicate general assembly, dimensions, weights, and materials.

Product Data: Provide catalog data indicating general assembly, dimensions, weights, materials, and certified performance ratings.

Manufacturer's Installation Instructions: Indicate assembly and setting operations.

OPERATION AND MAINTENANCE DATA

Submit under provisions of Section [01700.] [01730.]

Operation Data: Include assembly instructions, float adjustment, bleed rates, and electrical requirements.

Maintenance Data: Include instructions for lubrication filter replacement, cleaning and spare parts lists.

QUALIFICATIONS

Manufacturer: Company specializing in manufacturing the products specified in this Section with minimum [three] [_____] years [documented] experience.

PART 2 PRODUCTS

MANUFACTURERS

[___________________________________] Model [__________.]

[___________________________________] Model [__________.]

[___________________________________] Model [__________.]

Substitutions: Under provisions of Section [01600.] [_____.]

MANUFACTURED UNITS

Units: Factory assembled consisting of casing, tank, spray headers, nozzles, [spray pumps,] water and drain connections, and cooling coils.

Evaporation Performance: [_____] cu ft/min ([_____] cu m/sec) with maximum air pressure drop [_____] inch wg ([_____] Pa), saturation efficiency minimum [_____] percent.

Operating Static Pressure: [3 inch wg (750 Pa) negative.] [3 inch wg (750 Pa) positive.] [6 inch wg (1495 Pa) positive.]

CASING

Assembly: Galvanized steel, minimum 16 gage (1.5 mm), reinforced and braced with galvanized steel angles with cadmium plated cap screws.

Connection: 1-1/2 inch (30 mm) flanges on inlet and outlet with 1/4 x 1 inch adhesive backed neoprene gasket.

Doors: [20 x 36 inch (600 x 900 mm)] [14 x 19 inch (350 x 480 mm)] quick opening access door on one side with 1/4 inch (6 mm) thick plexiglass inspection window.

Finish: Two coats of [zinc chromate, iron oxide, phenolic resin] [__________] paint applied after assembly.

Removable Inlet Screen: Galvanized expanded metal on inlet side of dehumidifier.

Gasket and flange pipe penetrations, inspection panels, access doors, and other openings in casing.

DRAIN TANK

Tank: Welded [black] [stainless] steel, 12 inches (300 mm) deep, [10 gage (3.3 mm)] [3/16 inch (4.8 mm)], [finished inside and out with zinc chromate, iron oxide, phenolic resin paint] [prime coated] and coated inside with [1/8 inch (3 mm) asphalt mastic] [3/32 inch (2.5 mm) epoxy] [glass fiber reinforced plastic] coating.

Connections: [3/4 inch (19 mm)] [1 inch (25 mm)] adjustable float valve assembly with brass rod and [brass] [polystyrene] float; [2 inch (50 mm)] [3 inch (75mm)] [1- 1/2 inch (40 mm)] drain and overflow with removable copper suction screen.

Fabricate: Lap and weld corners watertight. Weld fittings and piping supports to tank.

External Spray Piping: [1-1/4 inch (32 mm) galvanized steel] [1-1/2 inch (38 mm) PVC] piping.

Spray Nozzles: Bronze, self-cleaning.

COOLING COILS

Coil: [ANSI/ARI 410;] copper tube, copper fin construction individually mounted on steel angle rails. Refer to Section 15790 and coil schedule for size and cooling capacity of unit.

Eliminators: [Galvanized steel,] [Type 304 stainless steel,] [PVC] mounted over drain pan.

Water Cooling Coil:

Size: [_____.]

Rows: [_____.]

Capacity: [_____] Btu/hr ([_____] W).

Entering Air Temperature: [_____] degrees F ([_____] degrees C) DB and [_____] degrees F ([_____] degrees celsius WB.

Leaving Air Temperature: [_____] degrees F ([_____] degrees C) DB and [_____] degrees F ([_____] degrees celsius WB.

Chilled Water: [_____] gpm([_____] L/sec) entering at [_____] degrees F ([_____] degrees C).

Refrigerant Cooling Coil:

Size: [_____.]

Rows: [_____.]

Capacity: [_____] Btu/hr ([_____] W).

Entering Air Temperature: [_____] degrees F ([_____] degrees C) DB and [_____] degrees F ([_____] degrees celsius WB.

Leaving Air Temperature: [_____] degrees F ([_____] degrees C) DB and [_____] degrees F ([_____] degrees celsius WB.

Refrigerant: [R-22] [_____] at [_____] degrees F ([_____] degrees C) saturated suction temperature.

SPRAY PUMPS

Type: [Vertical] [Horizontal] shaft, single stage, close coupled, radially split casing, for 125 psig (860 kPa) maximum working pressure.

Casing: Cast iron, with gage ports, drain plug, flanged suction and discharge.

Impeller: Bronze, fully enclosed, keyed to motor shaft extension.

Shaft: Stainless steel.

Seal: Carbon rotating against a stationary ceramic seat.

Performance:

Flow Capacity: [_____] gpm ([_____] L/sec).

Head: [_____] [[_____] kPa).

Motor: [_____] hp.

Model: [__________] manufactured by [_______________].

PART 3 EXECUTION

INSTALLATION

Install in accordance with manufacturer's instructions.

Install in ducts or casings in accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible.

Insulate exterior of unit same as specified for ductwork. Refer to Section 15290.

Place unit on 2 inch (50 mm) thick rigid insulation board same size as unit tank. Flash and counterflash with 20 gage (0.90 mm) galvanized steel on entering and leaving sides.

Connect unit to water supply. Provide gate valve on water supply line. Provide 3/4 inch (20 mm) hose bibb accessible from interior.

Provide shut-off valves for individual spray header isolation and balancing. [Arrange to permit step control of sprays.]

Pipe drain and overflow to nearest floor drain.

Bolt spray pump directly to tank fitting. Insulate external spray piping. Refer to Section 15252.

Provide globe valve and solenoid valve in 1/2 inch (12 mm) bleed line from drain.

****** [OR] ******

Provide 1/2 inch (12 mm) bleed line from spray pump discharge to nearest floor drain complete with globe valve set to pass 1/2 gph (0.002 cu m/sec) per 1000 cu ft/min (0.472 cu m/sec). Locate bleed line above flood level of drain tank.

Provide low water cut-off in drain pan to stop spray pump.

Connect unit to [cold water cooling] [refrigerant] system.

Connect unit to electrical supply.

SCHEDULE

Drawing_Code	SCD-1	SCD-1	SCD-1

Manufacturer

No. Required

Overall Height

Overall Width

Face Velocity

Saturation Efficiency

Coil

Type

Width

Height

Face Area

Rows

Circuits

Air

Flow Rate

Velocity

Static Pressure Drop

Heat Transfer Rate

Entering DB Temp

Entering WB Temp

Leaving DB Temp

Leaving WB Temp

Water

Flow Rate

Velocity

Head Loss

Entering Temp

Leaving Temp

Refrigerant

Type

Saturated Suction Temp

Pump

Flow Rate

Head

Motor

END OF SECTION