DESIGN A/E NOTE - GUIDE SPECIFICATION CONVENTIONS

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Rev 19JUN09 j:\Projects\Active\com-deca_design_criteria_revisions-04071\Guide Specifications\TJG Innformation

DeCA SPECIFICATION 15783

FOR

PACKAGED DUAL PATH DEHUMIDIFIERS

***DESIGN NOTES***

The designer shall locate the following notes in this specification and then edit specification as required. The notes can be located by using a word processor and search for “**”.

*****NOTE 1: Select fin material.

SECTION 15783 – PACKAGED DUAL PATH DEHUMIDIFIERS

TABLE OF CONTENTS

TABLE OF CONTENTS

PART I – GENERAL

1.1SECTION INCLUDES

1.2RELATED SECTIONS

1.3REFERENCES

1.4SUBMITTALS FOR REVIEW

1.5QUALITY ASSURANCE

1.6 REGULATORY REQUIREMENTS

1.7DELIVERY, STORAGE AND PROTECTION

1.8WARRANTY

1.9EXTRA MATERIALS

PART II – REQUIRED EQUIPMENT

2.1ACCEPTABLE MANUFACTURERS

2.2DEHUMIDIFIERS

2.3SYSTEM CONTROL FEATURES/STRATEGY

PART III – EXECUTION/INSTALLATION REQUIREMENTS

3.1EXAMINATION

3.2INSTALLATION

3.3MANUFACTURER’S FIELD SERVICES

SECTION 15783

PACKAGED DUAL PATH DEHUMIDIFIERS

PART 1 - GENERAL

1.1SUMMARY

1.1.1.Section Includes:

  1. Packaged roof top unit.
  2. Packaged indoor unit with remote air cooled condenser.
  3. Unit controls.

1.1.2.Related Sections:

  1. Section 01042 - Mechanical, Refrigeration, Food Service Equipment and Electrical Coordination.
  2. Section 01400 - Quality Control.
  3. Section 01720 – [Phased Turnover and] Project Closeout.
  4. .
  5. Section 15140 - Supports and Anchors.
  6. Section 15240 - Vibration Isolation and Seismic Restraints.
  7. Section 15651 - Product Refrigeration System.
  8. Section 15971 - Refrigeration Monitoring and Control System (RMCS).
  9. Section 15997 – Commissioning Mechanical Systems.
  10. Division 16 - Electrical.

1.2QUALITY CONTROL

1.2.1.The following publications form a part of this specification to the extent they are applicable:

  1. Section 01400 – Quality Control.
  2. AMCA 210 – Fan Performance Testing
  3. ANSI B3.16 – Roller Bearings, Load Rating and Fatigue Life
  4. ARI 210 Unitary AirConditioning Equipment.
  5. ARI 270 Sound Rating of Outdoor Unitary Equipment.
  6. ARI 410 – Air Cooling and Heating Coils.
  7. NFPA 70 National Electrical Code.
  8. NFPA 90A Installation of Air Conditioning and Ventilation Systems.

1.3SUBMITTALS

1.3.1.Submittals for Review:

  1. Section 01400 – Quality Control: Procedures for submittals.

insert project name and location

June 2010

PACKAGED DUAL PATH DEHUMIDIFIERS

15783-1

  1. Shop Drawings: Indicate capacity and dimensions of manufactured products and assemblies required for this project. Indicate electrical service with electrical characteristics and connection requirements, and duct connections.
  2. Product Data: Submit manufacturer’s specifications for dehumidifier units showing dimensions, weights, capacities, ratings, fan performance with operating point clearly indicated, motor electrical characteristics, gages and finishes of materials, and installation instructions.
  3. Submittals shall include but shall not be limited to the following:

(1)Equipment schedule containing dehumidification, cooling and heating capacities, fan motor data, electrical power data and filtration schedule.

(2)Technical Data Sheet containing design operating inlet and outlet conditions, air flow indicator settings, electrical power requirements and fan motor data.

(3)A system flow diagram showing air volumes and conditions throughout the system.

(4)A General Arrangement Diagram showing three views of the dehumidifier units with overall dimensions, general utility connection locations, ductwork connection points and bolting patterns, total weight and required service or equipment removal clearances.

(5)Control Diagrams and Parts Lists showing all electric circuits component ratings and any applicable setpoints.

(6)Technical data sheet on the individual control unit (ICU) for the dehumidification system and electrical diagram showing how ICU is connected to the dehumidification system.

(7)Piping Circuit diagrams for all piping circuits supplied.

  1. Operation and Maintenance data.

1.3.2.Submittals for Project Closeout:

  1. Section 01720 – [Phase Turnover and] Project Closeout.
  2. Operation and Maintenance Data: Include manufacturer's descriptive literature, operating instructions, installation instructions, maintenance and repair instructions, including lubrication instructions, desiccant filter replacement, motor and drive replacement, and spare parts lists. Include this data in maintenance manuals.
  3. Recommended Spare Parts List with long and short term requirements.
  4. The Contractor shall submit all certifications and testing data as a supplement to previously submitted O & M manuals at contract closeout

1.4QUALITY ASSURANCE

  1. Cooling coils shall be the ARI label.
  2. Fans shall be AMCA certified.

1.5QUALIFICATIONS

  1. Manufacturer: Company specializing in manufacturing the Products specified in this section with minimum five years documented experience.

1.6REGULATORY REQUIREMENTS

  1. Products Requiring Electrical Connection: Listed and classified by Underwriters' Laboratories, Inc. or ETL.

1.7DELIVERY, STORAGE, AND PROTECTION

  1. Protect units from physical damage by storing off site until roof mounting curbs are in place, ready for immediate installation of units.

1.8WARRANTY

  1. Provide a five year warranty to include coverage for refrigeration compressors and heat exchangers.

1.9EXTRA MATERIALS

  1. Section 01720 – [Phased Turnover and] contract closeout.
  2. Provide one set of filters.

PART 2 - PRODUCTS

2.1ACCEPTABLE MANUFACTURERS

  1. Seasons 4
  2. DesChamps
  3. AAON
  4. Munters Cargocaire

2.2REFRIGERANT

  1. Refrigerant shall be R410A.

2.3EFFICIENCY

a.EER shall not be less than 10.5.

2.4DEHUMIDIFIERS

*****EDIT AS APPROPRIATE

  1. General: [Packaged] [Indoor] [Mezzanine mounted] [with remote air cooled condensing unit] [condenser] [rooftop] units having gas burner and electric refrigeration using non-ozone depleting refrigerant.

*****EDIT AS APPROPRIATE

  1. Description: Self-contained, packaged, factory assembled and prewired, consisting of cabinet and frame, supply fan, heat exchanger and burner, heat recovery coil )coil provided under Section 15651 and factory installed under this section), controls, air filters, and refrigerant cooling coils. [Remote] [condensing unit with] [and] compressors [remote air cooled condenser.]. [Condenser coils and condenser fan shall be in a separate roof mounted unit]. Coils shall be arranged for reheat control with the cooling coils upstream followed by the heat recovery coil and finally the gas heating section. The cooling coils shall be arranged for cooling of return and outdoor air by separate refrigeration circuits (dual path) and for complete bypassing of a portion of return air.

2.5CABINET

*****Use following paragraph unless near salt water****

  1. [Aluminum or galvanized steel double wall panels with baked enamel finish and rigid internal channel frame, fully gasketed joints. Structural members shall be minimum 18 gage (1.20 mm)]. Drain pans shall be stainless steel.

****Use following paragraph within 30mmiles of salt water*****

  1. [Aluminum or Stainless steel double wall panels with rigid internal stainless steel or aluminum channel frame, fully gasketed joints. Bottom of unit shall be panned with aluminum. Drain pans shall be stainless steel. Filter frames shall be aluminum extrusions. All internal and external surfaces, structural elements, and fasteners shall be aluminum or stainless steel.]
  1. Access doors with flush cam type or locking door handle type with piano hinges and gasketed heads jambs and sills with knife edge meeting gasket for positive seal. Access doors frames shall be a minimum 20 gage (0.90 mm).
  2. Exterior surface shall be cleaned and finished with an air dry enamel. All coils and controls shall be removable thorough the access doors.
  3. Cabinet Insulation shall be 2 inch (50 mm) thick (R-7) for with full inner galvanized steel or aluminum panel.

[e.Roof Mounting Curb: 14 inches (350 mm) high galvanized steel, channel frame with gaskets, nailer strips, insulated, top to be level, designed in accord with Section 15140 SUPPORTS AND ANCHORS [and Section 15240 VIBRATION ISOLATION AND SEISMIC RESTRAINT.]

2.6ROOF TOP MECHANICAL UNIT ROOF CURB ANCHORAGE BRACKETS

  1. Provide mechanical unit manufacturer engineered galvanized metal brackets for anchorage of Roof Top Mechanical Units to manufactured roof curbs.
  2. Design and fabricate brackets to anchor mechanical units to resist forces due to design wind pressure and seismic forces. Wind load design requirements are as indicated on structural drawing.

2.7SUPPLY FANS

  1. Backward inclined airfoil centrifugal type, enameled steel construction, resiliently mounted with V-belt drive and adjustable variable pitch motor pulley to be replaced with fixed pitch sheave after balancing, and rubber isolated hinge mounted premium efficiency open drip proof motor or direct drive as indicated.
  2. Isolate complete fan assembly.
  3. Refer to Section 15240 Motors.
  4. All fans shall be vibration isolated and factory balanced such that maximum displacement in any plane does not exceed 1.5 mils for fans operating at or below 2000 RPM or 1.0 mils above 2000 RPM. Fans shall operate at 80% or less of their first critical speed.

****Edit for variable speed drive****

  1. [Provide variable speed fan drive.]

****Use following paragraph within 30mmiles of salt water*****

  1. [Fan construction shall be aluminum or epoxy coated steel.]

2.8FILTERS

*****Specify MERV 13 filters for LEED points****8

  1. Outside air inlets and return air plenums shall be equipped with disposable roughing filters ahead of pleated disposable type filters with nonwoven pleated media held in place by a welded wire support grid. All filters shall be mounted such that air bypass is minimized. Pleated media filters shall be MERV 8per ASHRAE Test Standard 52.2-2007

2.9DAMPERS

  1. Provide manual balancing dampers with position indicating quadrants and locking hardware for balancing of the by pass air stream and motorized dampers for outdoor and return air service.

***Provide aluminum dampers within 30 miles of the sea coast***

  1. All dampers shall have heavy gauge[galvanized steel frames, galvanized steel blades with oil impregnated or synthetic bushings], [aluminum blades and frames, plated steel axels with synthetic bushings] and plated interconnecting linkage for smooth operation. Dampers shall be opposed blade type equipped with blade edge and end seals to minimize leakage. All motorized dampers shall be equipped with operators to provide automatic control operation.

2.10HEAT EXCHANGER AND BURNER

  1. Gas Burner: Two stage (NOT MODULATING) natural gas burner with adjustable combustion air supply, pressure regulator, gas valves, manual shut-off, intermittent spark or glow coil ignition, flame sensing device, and automatic 100 percent shut-off pilot. Burner shall have a forced draft or combustion blower to provide positive venting.
  2. Gas Burner Safety Controls: Energize ignition, limit time for establishment of flame, prevent opening of gas valve until pilot flame is proven, stop gas flow on ignition failure, energize blower motor, and after air flow proven and slight delay, allow gas valve to open.
  3. High Limit Control: Temperature sensor with fixed stop at maximum permissible setting, de-energize burner on excessive bonnet temperature and energize burner when temperature drops to lower safe value.
  4. Supply Fan Control: Temperature sensor sensing bonnet temperatures and independent of burner controls, with provisions for continuous fan operation.
  5. Stainless steel heat exchanger of welded construction.

2.11EVAPORATOR COILS

****NOTE: Include the following for maximum energy consumption reduction.

  1. [Maximum face velocity shall not exceed 350 fpm to reduce supply fan horsepower requirement]

****NOTE: Select copper fin coil and stainless steel end plates for outdoor air within 30 miles of the seacoast.

  1. Provide copper tube aluminum fin coil assembly with stainless drain pan [and coil endplates]and connection for return air coil. Provide copper tube, [copper] [aluminum] fin coil with stainless steel drain pan for outdoor air coil.
  2. Coils shall be direct expansion type constructed with ½ in or 5/8 in. OD seamless copper tubes mechanically expanded for a compression bond to fins. All evaporator coils shall be counter flow circuited and equipped with seamless copper tube pressure type distributors. DX coil will be designed for a maximum working pressure of 400 PSIG. Coil assemblies shall include 16 gage galvanized steel casings with a support mounting structure that permits coil removal through side access. Assemblies shall include an insulated drain pan complete with exterior trap.
  3. All direct expansion coils shall be equipped with a thermostatic expansion valve with external equalization and liquid line solenoid valve. Provide capillary tubes or thermostatic expansion valves for units of 6 tons (21 kw) capacity and less, and thermostatic expansion valves and alternate row circuiting for units 7.5 tons (26 kw) cooling capacity and larger.

2.12COMPRESSOR

  1. Provide hermetic scroll compressors, resiliently mounted with positive lubrication, crankcase heater, high and low pressure safety controls, motor overload protection, suction and discharge service valves and gage ports, and filter drier.
  2. Five minute timed off circuit to delay compressor start.
  3. Provide step capacity control where scheduled by cycling compressors.

2.13AIR COOLED CONDENSER

  1. [Remote] [Integral] air cooled condenser.

****Select copper fin coil and stainless steel end plates within 30 miles of the seacoast.

  1. Provide copper tube [aluminum fin] [copper fin] coil assembly [with stainless steel end plates] sub cooling rows and coil guard.
  2. Provide direct drive propeller fans, resiliently mounted with fan guard, motor overload protection, wired to operate with compressor. Provide high efficiency fan motors.
  3. Provide refrigerant liquid temperature switches to cycle condenser fans for operation to 0 degrees F.
  4. Maximum working pressure 600 psi.

*****Use following paragraph unless near salt water****

  1. [Aluminum or galvanized steel panels with baked enamel finish and rigid internal channel frame. Structural members shall be minimum 18 gage (1.20 mm)].

****Use following paragraph within 30mmiles of salt water*****

  1. [Aluminum or Stainless steel panels with rigid stainless steel or aluminum channel frame, All internal and external surfaces, structural elements, and fasteners shall be aluminum or stainless steel. Fan blades and venturis shall be aluminum or powder coated steel.]

insert project name and location

June 2010

PACKAGED DUAL PATH DEHUMIDIFIERS

15783-1

2.14MIXED AIR SECTION

  1. Dampers: Provide motorized outside air dampers for fixed outside air quantity. Damper construction shall be specified in “DAMPERS” above.
  2. Damper Operator: 24 volt with gear train sealed in oil with spring return on units 7.5 ton (26 kw) cooling capacity and larger.

2.15HEAT RECOVERY COIL

  1. Shall be provided under Section 15651. Under this section, provide a coil cabinet and mount the coil in the unit at the factory.
  2. Coils shall be counterflow circuited. Face air flow velocities shall not exceed 550 FPM. Coils shall be designed for a maximum working pressure of 400 PSIG.
  3. The heat reclaim coils shall be provided by the product refrigeration manufacturer and installed by the HVAC contractor.

2.16OPERATING CONTROLS

  1. Provide terminal strip on unit for connection of operating controls to the Section 15971 RMCS. See Section 15971 for control functions required. Install and wire the ICU provided by Section 15971.
  2. Interface controls with Section 15971. Provide all controls or devices required to perform the control and monitoring functions specified in Section 15971, but not provided by 15971.

2.17DESCRIPTION OF OPERATION

***A/E shall edit as necessary. This paragraph shall be edited to agree exactly with Section 15971.

  1. Space temperature and humidity shall be controlled by a minimum of three individual cooling stages utilizing two air paths. The outside air path will process all of the outside air (no bypass) and provide most of the dehumidification required for the space. An outdoor air precooling coil and dehumidification coils (6-row minimum) shall be used. The return air path will have a cooling coil to cool the return air as required to provide the remaining cooling required for the space. Some return air may be bypassed.
  2. The air paths will then mix heating will be accomplished by utilizing reclaimed refrigeration heat through heat reclaim coils, supplemented by a two stage gas fired power burner. The reclaimed heat will be used for reheat if required, and will provide the main heat as reclaimed heat is available. The gas heating will only be used if additional capacity is required.
  3. Fan operation shall be continuous. Fan shall run at high speed (100%) in occupied mode and for cooling dehumidification operation and at low speed (50%) at all other times.
  4. Compressors shall be sized to match the cooling/dehumidification requirements of the two paths with the evaporator coils.
  5. Multiple Condenser fans shall be controlled from liquid temperature and shall be cycled to maintain a target liquid temperature.
  6. Heat reclaim will be used for reheat and for initial stages of heat.
  7. Control the gas heating section from space temperature only after maximum utilization of heat reclaim has been realized. Auxiliary heat shall not be used for reheat control.
  8. The dehumidification coil in the outdoor air path is stage 1 and the outside air precooling coil is stage 2. The return air cooling coil is stage 3. Stage 1, 2 and 3 coils shall be controlled from space humidity in that order to maintain 52OF dewpoint. Precooling coil shall be locked out below an ambient temperature of 72 degrees F.
  9. Outside air and return air motorized dampers shall be provided. The outside air (or night setback) damper shall be open during the occupied cycle and closed in the unoccupied cycle. The outside air (or night setback) damper shall be mechanically linked to the return air damper so the return air damper shall open when the outdoor air (or night setback) damper closes, allowing return air to follow both air paths.
  10. To allow the specified air flow rates in the two paths, an array of static pressure probes shall be positioned to monitoring internal air pressure drops through key elements of the dual path system. Each air path shall have built-in balancing dampers for air volume adjustment.
  11. Provide a differential pressure switch to monitor the operation of the main blower.
  12. The temperature and humidity set points shall be:

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