USACE / NAVFAC / AFCESA / NASA UFGS-23 72 26.00 10 (April 2008)
--------------------------------
Preparing Activity: USACE Superseding
UFGS-23 72 26.00 10 (January 2008)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 23 72 26.00 10
DESICCANT COOLING SYSTEMS
04/08
NOTE: This guide specification covers the requirements for desiccant cooling
systems, both solid and liquid types, which offset the latent cooling load by
removing moisture from the outside air before it reaches the cooling coil.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AIR-CONDITIONING, HEATING AND REFRIGERATION INSTITUTE (AHRI)AHRI 210/240(2006) Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump EquipmentAHRI 700(2004) Specifications for Fluorocarbon Refrigerants][AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS (ASHRAE)ASHRAE 15 & 34WARNING: Text in tags exceeds the maximum length of 300 characters][ASME INTERNATIONAL (ASME)ASME B31.1(2007; Addenda 2008) Power PipingASME BPVC SEC IX(2007; Addenda 2008) Boiler and Pressure Vessel Code; Section IX, Welding and Brazing Qualifications][ASTM INTERNATIONAL (ASTM)ASTM A 307(2007b) Standard Specification for Carbon Steel Bolts and Studs, 60 000 PSI Tensile StrengthASTM B 209(2007) Standard Specification for Aluminum and Aluminum-Alloy Sheet and PlateASTM B 209M(2007) Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate (Metric)ASTM B 210(2004) Standard Specification for Aluminum and Aluminum-Alloy Drawn Seamless TubesASTM B 210M(2005) Standard Specification for Aluminum and Aluminum-Alloy Drawn Seamless Tubes (Metric)ASTM D 1784(2008) Standard Specification for Rigid Poly(Vinyl Chloride) (PVC) Compounds and Chlorinated Poly(Vinyl Chloride) (CPVC) CompoundsASTM F 104(2003) Standard Classification System for Nonmetallic Gasket Materials][NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)NEMA MG 1(2007; Errata 2008) Standard for Motors and Generators]1.2 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are for [Contractor Quality Control approval.] [information only. When used, a designation following the "G"
designation identifies the office that will review the submittal for the Government.] Submit the following in
accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Drawings[; G][; G, [_____]]
Drawings, at least [5 weeks] [_____] prior to beginning construction, providing adequate detail
to demonstrate compliance with contract requirements.
SD-03 Product Data
Verification of Dimensions
A letter, at least 2 weeks prior to beginning construction, indicating the date the site was
visited, confirming existing conditions, and noting any discrepancies found.
Standard Products[; G][; G, [_____]]
Manufacturer's catalog data, at least [5 weeks] [_____] prior to beginning construction, highlighted
to show model number, size, options, performance charts and curves, etc., in adequate detail
to demonstrate compliance with contract requirements. Performance charts and curves shall provide
performance data over the full range of outdoor conditions for which dehumidification will be
required, with the conditions defined by the Contracting Officer. Manufacturer shall supply
data on all energy recovery methods and equipment available for the system. Data shall include
manufacturer's recommended installation instructions and procedures. If vibration isolation
is specified for a unit, vibration isolator literature shall be included containing catalog
cuts and certification that the isolation characteristics of the isolators provided meet the
manufacturer's recommendations.
Spare Parts
Spare parts data for each different item of material and equipment specified.
Qualifications
[_____] copies of qualification procedures, and list of names and identification symbols of
qualified welders and welding operators, prior to non-factory welding operations.
Field Instructions
Posted instructions, at least 2 weeks prior to construction completion, including equipment
layout, wiring and control diagrams, piping, valves and control sequences, and typed, condensed,
operation instructions. The condensed operation instructions shall include preventative maintenance
procedures, methods of checking the system for normal and safe operation, and procedures for
safely starting and stopping the system. The posted instructions shall be framed under glass
or laminated plastic and be posted where indicated by the Contracting Officer.
Performance Tests
Test schedules, at least 2 weeks prior to the start of the field tests and the system performance
test. The schedules shall identify the date, time, and location for the performance test.
Demonstrations
A schedule for training demonstrations, at least 2 weeks prior to the date of the proposed
training course, identifying the date, time, and location for the training.
SD-06 Test Reports
Performance Tests[; G][; G, [_____]]
A report documenting the data taken versus the specified performance criteria, upon completion
of installation and performance testing of the system. [Six] [_____] copies of the bound report
(216 by 279 mm 8-1/2 by 11 inches) shall be provided. The report shall document compliance
with the specified performance criteria upon completion and testing of the system. The report
shall indicate the number of days covered by the tests and any conclusions as to the adequacy
of the system. The report shall also include the following information and shall be taken at
least three different times at outside dry-bulb temperatures that are at least 5 degrees C F
apart.
Inspections
A bound inspection report (216 by 279 mm 8-1/2 x 11 inches) at the completion of one year
of service. The report shall identify the condition of the desiccant system and shall include
a comparison of the condition of the desiccant system with the manufacturer's recommended operating
conditions.
SD-07 Certificates
Standard Products[; G][; G, [_____]]
Proof of compliance with AHRI, ASHRAE, ASME, or UL requirements where specified for the system,
components, or equipment. The label or listing of the specified agency shall be acceptable
evidence. In lieu of the label or listing, a written certificate from an approved, nationally
recognized testing organization equipped to perform such services, shall be submitted stating
that the items have been tested and conform to the requirements and testing methods of the specified
agency. When performance requirements of this project's drawings and specifications vary from
standard AHRI rating conditions, computer printouts, catalog, or other application data certified
by AHRI or a nationally recognized laboratory as described above shall be included. If AHRI
does not have a current certification program that encompasses such application data, the manufacturer
shall self certify that his application data complies with project performance requirements.
SD-10 Operation and Maintenance Data
Operation and Maintenance Manuals;G, [_____]
[Six][_____] complete bound copies (216 by 279 mm 8-1/2 x 11 inches) of an operation and maintenance
manual listing step-by-step procedures required for system startup, operation, maintenance,
and shutdown. The manual shall include the manufacturer's name, model number, parts list, service
manual, and a brief description of all equipment and their basic operating features. The manual
shall include routine maintenance procedures, possible breakdowns and repairs, and a trouble
shooting guide. The manuals shall include piping and equipment layouts and simplified wiring
and control diagrams of the system as installed.
1.3 QUALITY ASSURANCE
1.3.1 Qualifications
NOTE: If the need exists for more stringent requirements for weldments, delete
the first bracketed statement, otherwise delete the second.
Piping shall be welded in accordance with the qualified procedures, using performance qualified welders and welding
operators in accordance with ASME BPVC SEC IX. Welding procedures qualified by others, and welders and welding
operators qualified by another employer may be accepted as permitted by ASME B31.1. Notify the Contracting Officer
24 hours in advance of tests and perform the tests onsite, if practical. The welder or welding operator shall
apply the assigned symbol near each weld personally made as a permanent record. Weld structural members in accordance
with [Section 05 05 23 WELDING, STRUCTURAL][welding and nondestructive testing procedures specified in Section
43 02 00 WELDING PRESSURE PIPING].
1.3.2 Drawings
Because of the small scale of the drawings, it is not possible to indicate all offsets, fittings, and accessories
that may be required. Carefully investigate the plumbing, fire protection, electrical, structural and any other
features or conditions that would affect the work to be performed and arrange such work accordingly, furnishing
required offsets, fittings, and accessories to meet such features or conditions. Submit Drawings consisting
of:
a. Equipment layouts which identify assembly and installation details to include energy recovery
equipment.
b. Piping layouts which identify all valves and fittings.
c. Plans and elevations which identify clearances required for maintenance and operation.
d. Wiring diagrams which identify each component individually, by showing actual location
in equipment, and schematically, by showing all interconnected or interlocked relationships
between components.
e. Foundation drawings, bolt-setting information, and foundation bolts prior to concrete
foundation construction for all equipment indicated or required to have concrete foundations.
f. Details, if piping and equipment are to be supported other than as indicated, which include
loading and type of frames, brackets, stanchions, or other supports.
1.4 DELIVERY, STORAGE, AND HANDLING
All equipment delivered and placed in storage shall be stored with protection from the weather, humidity and
temperature variations, dirt and dust, or other contaminants.
1.5 EXTRA MATERIALS
Submit spare parts data for each different item of material and equipment specfied, after approval of the detail
drawings and not later than [_____] months prior to the date of beneficial occupancy. The data shall include
a complete list of parts and supplies, with source of supply.
PART 2 PRODUCTS
2.1 STANDARD PRODUCTS
NOTE: Desiccant cooling systems are of two basic types: dry desiccant on a
rotor with hot air regeneration and liquid desiccant with spray coils and heated
desiccant.
A schematic drawing, sequence of operation, and an equipment schedule must be
included on the drawings. Equipment which the basic dehumidification system
vendor lists as optional or "provided by others" must be clearly shown and sized.
Provide materials and equipment which are the standard products of a manufacturer regularly engaged in the manufacturing
of such products and that essentially duplicate equipment which is similar in material, design, and workmanship.
The standard products shall have been in satisfactory commercial or industrial use for two years prior to bid
opening. The two-year use shall include applications of equipment and materials under similar circumstances
and of similar size. The two years experience shall be satisfactorily completed by a product which has been
sold or is offered for sale on the commercial market through advertisements, manufacturer's catalogs, or brochures.
Products having less than a two-year field service record will be acceptable if a certified record of satisfactory
field operation, for not less than 6000 hours exclusive of the manufacturer's factory tests, can be shown. All
products shall be supported by a service organization. Submit a certified list of qualified, permanent service
organizations for support of the equipment including their addresses and qualifications. These service organizations
shall be reasonably convenient to the equipment installation and shall be able to render satisfactory service
to the equipment on a regular and emergency basis during the warranty period of the contract. The system shall
be a complete stand alone system with all necessary controls, motors, fans, rotors, motors, drive components,
pumps, reactivation components and filtration to provide automatic continuous operation. Internal regeneration
heat sources shall be a part of the system, except external heat sources may be used under the following conditions:
connections to external heat sources shall be fully coordinated with the system manufacturer, and connecting
equipment such as pumps, piping, traps, etc., shall be as shown on the drawings and schedules. The desiccant
shall be of the [solid type on a rotary wheel][liquid type utilizing spray coils].
2.2 MATERIALS
2.2.1 Gaskets
Gaskets shall conform to ASTM F 104 classification for compressed sheet with nitrile binder and acrylic fibers
for maximum 371 degrees C 700 degrees F service.
2.2.2 Bolts and Nuts
Bolts and nuts, except as required for piping applications, shall be in accordance with ASTM A 307. The bolt
head shall be marked to identify the manufacturer and the standard with which the bolt complies in accordance
with ASTM A 307.
2.3 DESICCANT SYSTEMS
NOTE: Desiccant systems are used basically for large latent loads. These systems
should be engineered around a total system. They can be used in buildings with
humidity requirements lower than mechanical equipment capacity, for preprocessing
of OA to lower the load on mechanical systems, and as liquid systems to maintain
exact humidity requirements during all seasons. The designer should look at
existing energy sources for regeneration when considering a desiccant system
to maximize equipment usage and energy savings. Application of desiccant systems
should involve manufacturer input when coordinating equipment usage.
Designer should determine the type of DESICCANT SYSTEM required and delete the
unwanted systems.
2.3.1 Solid Desiccant System
NOTE: Desiccant cooling system equipment is sized to meet space and ventilation
latent cooling loads. Typically, the desiccant dehumidifies ventilation air
so that, when the desiccant ventilation air is mixed with return air from the
space, the resulting mixture is of sufficiently low specific humidity to satisfy
the latent load of the space. The refrigerant-based post-cooling system is
sized to reduce the dry-bulb temperature of the mixture to handle the space
sensible cooling load. In some cases, an optional pre-cooling coil is placed
upstream of the desiccant wheel so that the wheel can more effectively dehumidify
the outside air to be introduced for ventilation or makeup. Optional heating
coils may be added in the desiccant unit enclosure to partially or totally handle
the space heating loads.
The unit shall be a complete, factory assembled and tested system, suitable for outdoor installation. Each unit
shall produce a capacity as rated in accordance with AHRI 210/240. It shall be designed for either curb mounting
or structural steel support. The unit shall include the following components as defined in paragraph SYSTEM
COMPONENTS:
a. Desiccant Rotor
b. Thermal Rotor (or heat pipe)
c. Supply Fan
d. Regeneration Fan
e. Regeneration and Process Heating System
f. Filters
g. Indirect Evaporative Cooling System
h. Gas fired Boiler (optional)
i. Circulating pumps (boiler, evaporative cooling)
j. Refrigeration Section (optional) for pre- and/or post-cooling
2.3.1.1 Control Package
Each unit shall be factory wired and equipped with a central electrical control panel mounted inside the service
compartment. Variable-speed drive controller, if provided, shall also be mounted inside the service compartment.
Switched lighting shall be provided in the service compartment so that the panel can be easily seen. Compartment
shall be ventilated, if necessary, for cooling variable speed drive controller. A single power supply shall
be required. All internal wiring shall be in accordance with the National Electrical Code. All electrical components
required for automatic operation, based on signals from remotely mounted humidity and temperature sensors/controllers,
shall be included. Connections to remote devices shall be made at the marked terminals. The internal control
panel shall report discharge temperature and humidity. Additional reporting of all control data shall be available
to a central control station, as specified in Section 23 09 23 DIRECT DIGITAL CONTROL FOR HVAC AND OTHER LOCAL
BUILDING SYSTEMS.
2.3.1.2 Unit Mounting
The unit shall be [curb mounted] [structural steel supported]. The entire unit shall be isolated from the building
structure on vibration isolators with submitted and published load ratings. Vibration isolators shall have isolation
characteristics as recommended by the manufacturer for the unit supplied and the service intended.
2.3.2 Liquid Desiccant System
NOTE: Liquid desiccant systems are capable of maintaining year round humidity
control due to characteristics of the conditioner solution and the units ability
to maintain the concentration of the solution. Additionally, these units are
capable of lowering the air temperature because the conditioner solution passes
through a heat exchanger utilizing a cold liquid such as chilled water. The
designer should work with the manufacturer to integrate these systems with the
existing mechanical units. One approach would be to use the desiccant system
to precondition supply air for several chiller-AHU systems.
The unit shall be a complete, factory assembled and tested, system suitable for outdoor installation. Each unit
shall produce a capacity as rated in accordance with AHRI 210/240. It shall be designed for [curb mounting]
[structural steel support]. The unit shall include the following components as defined in paragraph SYSTEM COMPONENTS:
a. Conditioner unit
b. Conditioner cooler
c. Regenerator
d. Regenerator heater
e. Level control
f. Filter screening
g. Freestanding pump assembly
h. Make up water system
i. Conditioner fan
j. Regenerator fan
2.3.2.1 Control Panel
Each unit shall be factory wired and equipped with a central electrical control panel mounted inside the service
compartment. A single power supply shall be required. All internal wiring shall be in accordance with the National
Electrical Code. All electrical components required for automatic operation, based on signals from remotely
mounted humidity and temperature sensors/controllers, shall be included. Connections to remote devices shall
be made at the marked terminals. The internal control panel shall report discharge temperature and humidity.
Additional reporting of all control data shall be available to a central control station, as specified in Section
23 09 23 DIRECT DIGITAL CONTROL FOR HVAC AND OTHER LOCAL BUILDING SYSTEMS.
2.3.2.2 Equipment Mounting
Liquid desiccant systems shall have the conditioner and regenerator units set on level concrete floor or slab.
Before the equipment is set in place, the floor shall be sealed with epoxy sealant. Unit shall be surrounded
by a curb.
2.6 UNIT CONSTRUCTION
2.4 Solid Desiccant System
Unit shall be suitable for outdoor installation. It shall be designed for either structural or curb mounting
without field modification. The enclosure system shall be air-tight (2% maximum leakage at 150% design static
pressure from section to section). The unit base shall be constructed of formed minimum 10 GA steel coated with
red- oxide primer. Cross members shall be located to support each major component. Lifting lugs shall be fitted
to appropriate structural members. Unit exterior shall be painted with a low-gloss enamel.
2.4.1 Housing
The unit housing and internal partitions shall be constructed of minimum 18 GA galvanized steel with the exterior
panels treated to allow for painting. All external walls shall be insulated with foil-faced fiber glass insulation
at least 25 mm 1 inch thick and secured by permanent mechanical fasteners welded to the panels. Adjoining panels
shall be sealed by permanent mechanical fasteners welded to the panels. Adjoining panels shall be sealed to
one another with silicone compound, as specified in Section 23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
2.4.2 Service Panels
Removable service access panels shall be provided for all components. The openings shall be of sufficient size
to allow service to all maintenance items. All service panels shall be provided with resilient gaskets and hardware
to assure compression. Access doors shall be provided for boiler and control sections and shall have continuous
hinges. Roof panels shall be sealed to provide a weather-tight enclosure.
2.5 Liquid Desiccant System
The unit shall consist of conditioner and regenerator watertight housings containing the sump of vinylester FRP
with additives to achieve a U.L. Class 1 flame spread rating, or equal. The conditioner cooler, and regenerator
heater shall be of the plate-and-frame type, with carbon steel frame carrier bars and tiebolts; titanium plates
and nitrile or EPDM gaskets.
2.5.1 Piping
NOTE: Edit Section 22 00 00 to the extent necessary to specify FRP and CPVC
piping, valves and pressure testing of piping system.
The conditioner piping shall be FRP or CPVC rated for continuous service at 107 degrees C 225 degrees F with
the desiccant solution. FRP piping shall be used for the regenerator. Blackiron, galvanized and stainless steel
shall not be used. CPVC piping shall be Schedule 80, Type IV, Grade 1, 4120, in accordance with ASTM D 1784,
as specified in Section 22 00 00 PLUMBING, GENERAL PURPOSE. The piping shall be supported so that no stress
is placed on connections to the equipment. Piping shall be installed at least 610 mm 2 ft away from all maintenance
access openings and belt guards. Solution pump discharge piping must be arranged to allow removal of the pump
from the pump tank. The pump discharge piping shall incorporate a 90 degree elbow or a vertical spool piece
at least 1.2 m 4 ft long so the pump can be lifted vertically from the tank. All piping shall be pressure tested
for leaks before insulating. If possible, equipment start-up should be completed before the insulation is applied.
2.5.2 Valves and Thermowells
Valves in the conditioner solution piping shall be made of CPVC, thermoplastic-lined cast iron, or as recommended
by the manufacturer. Thermowells in the solution piping shall be monel or TFE-coated steel. Stainless steel thermowells
are not acceptable. All pipe fittings shall be flanged when possible. Threaded fittings and connections shall
be avoided. Red rubber or neoprene full-face gaskets shall be used in flanged connections.
2.5.3 Insulation
Conditioners shall be insulated whenever a coolant other than cooling tower water is used to prevent surface
condensation. The entire unit including the solution and coolant piping shall be insulated. Flexible rubber,
rigid foam plastic, or other non-permeable, vapor-tight insulation material shall be used for conditioners.
When the equipment is installed outside, an ultraviolet and weather protective coating should be applied to the
insulation. Regenerators and steam or hot water piping should be insulated with 50 mm 2 inch of rigid, foil-
or plastic-faced, fiberglass board. Solution piping shall be insulated if required for personnel protection.
If the equipment is installed outside, weather protective covering shall be applied. The outer casing of the
conditioner and regenerator shall not be penetrated with insulation fasteners. Contact cement or other adhesive
as recommended by the insulation manufacturer for use with an FRP substrate shall be used for insulation fastening.
Insulation shall conform to Section 23 07 00 THERMAL INSULATION FOR MECHANICAL SYSTEMS.
2.5.4 Safety Requirements
NOTE: Catwalk, ladder and guardrail may be required. Select the applicable
bracketed items, delete the others, and indicate on the drawings the selected
items. If not applicable, delete the entire sentence within the brackets.
Exposed moving parts, parts that produce high operating temperature, parts which may be electrically energized,
and parts that may be a hazard to operating personnel shall be insulated, fully enclosed, guarded, or fitted
with other types of safety devices. Safety devices shall be installed so that proper operation of equipment
is not impaired. [[Catwalk][Ladder][Guardrail] shall be provided where indicated and in accordance with Section
[05 50 13 MISCELLANEOUS METAL FABRICATIONS][05 51 33 METAL LADDERS].]
2.5.5 Electrical Work
NOTE: Where motor starters for mechanical equipment are provided in motor-control
centers, the references to motor starters will be deleted.
Electrical equipment, motors, motor efficiencies, and wiring shall be in accordance with Section 26 20 00 INTERIOR
DISTRIBUTION SYSTEM. Electrical motor driven equipment specified shall be provided complete with motors, motor
starters, and controls (including variable speed control of process air flow for solid units, where applicable).
Electrical characteristics and enclosure type shall be as shown, and unless otherwise indicated, all integral
size motors with open, dripproof, or totally enclosed fan cooled enclosures, shall be premium efficiency type
in accordance with NEMA MG 1. Field wiring shall be in accordance with manufacturer's instructions. Each motor
shall conform to NEMA MG 1 and be of sufficient size to drive the equipment at the specified capacity without
exceeding the nameplate rating of the motor. All motors shall be continuous duty with the enclosure specified.
Motor starters shall be provided complete with thermal overload protection and other appurtenances necessary
for the motor control indicated. Motors shall be furnished with a magnetic across-the-line or reduced voltage
type starter as required by the manufacturer. Motor starter shall be provided with [NEMA 1][NEMA 3R][NEMA [_____]]
enclosures. Manual or automatic control and protective or signal devices required for the operation specified
and any control wiring required for controls and devices specified, but not shown, shall be provided.
2.5.6 Duct Work
2.5.6.1 Plenums and Ductwork
Desiccant units shall be provided with flanges on the air openings for duct connection. Inlet and outlet plenums
shall be bolted to the flange with a gasket between the connection. Access doors, for servicing diffusers and
eliminators, shall be provided in the inlet and outlet plenums. Inlet ductwork must be designed to allow uniform
distribution of air across the entire opening. Outlet plenums and ductwork must allow adequate room for servicing
the eliminators and must provide proper airflow through the equipment. Plenum and ductwork sizes shall be as
shown and specified in Section 23 00 00 AIR SUPPLY, DISTRIBUTION, VENTILATION, AND EXHAUST SYSTEM.
2.5.6.2 Regenerator Exhaust Ductwork
The regenerator exhaust ductwork shall be made of glass-fiber reinforced polyester (FRP) or monel. FRP must
be rated for continuous duty at 82 degrees C 180 degrees F. Duct joints should be of watertight construction.
The exhaust plenum and duct should incorporate a drip collar to capture any condensation that occurs inside the
duct. Long horizontal duct runs should be pitched slightly in the direction of air flow, and shall incorporate
low-point condensate drains.
2.6 SYSTEM COMPONENTS
2.6.1 Desiccant Rotor
Dehumidifiers shall be non-cyclic adsorption type with a single desiccant rotary structure designed for continuous
operation. Construction arrangement shall provide counter flow of process and regeneration air streams with
full face pressure seals to prevent cross leakage with static pressure differentials up to 200 mm 8 inches water
gauge. The rotary structure shall consist of a stable, hygroscopic desiccant material, such as Silica Gel, Titanium
Silicate, or a Zeolite, deposited on a honey-combed substrate designed to maximize the desiccant area exposed
to the air stream and minimize the thermal carryover from the regeneration side to the adsorption side. The
design shall ensure laminar air flow through the structure for minimum pressure loss. The rotor shall be complete
with an electric motor with over-current protection and a speed reducer assembly driving the rotor through a
flexible circumferential drive belt. A slack side belt tensioner shall be included for automatic take-up.
2.6.2 Heat Exchanger
2.6.2.1 Thermal Rotor
The thermal rotor shall be of the rotary, non-hygroscopic type, to minimize the transfer of water vapor between
the process and regeneration sides of the unit. The rotor shall be constructed and sized to maximize the transfer
of heat from the supply air stream to the regeneration air stream while minimizing the transfer of moisture back
to the supply air stream. Supply and cooling air streams shall be counter flow and the component fitted with
full face contact seals on both sides to prevent leakage.
2.6.2.2 Heat Pipe
NOTE: The designer will research local conditions to determine the effect of
corrosive atmosphere on dissimilar metals. Where condenser or evaporator coils
are to be installed in corrosive atmospheres, the specification for coils and
fins will be rewritten for these specific conditions. Consideration should
be given to the following coil and fin combinations based on past experience
with the suitability of these materials in dealing with the local conditions.
a. Copper coil and aluminum fins, coated.
b. Copper coil and copper fins, coated.
c. Aluminum coil and aluminum fins, coated.
d. Aluminum coil and aluminum fins, uncoated.
e. Copper coil and copper fins, uncoated.
Coating may be either phenolic or vinyl. For coils with relatively close fin
spacing such as those found in most unitary equipment, the phenolic coating
is preferred. Phenolic has less tendency to bridge across the fins than vinyl,
has better thermal conductivity than vinyl and in many conditions weathers better
than vinyl.
Heat pipe coils shall be of the extended-surface fin-and-tube type and shall be constructed of seamless [copper]
[or] [aluminum] tubes with compatible [copper] [or] [aluminum] fins. On heat pipes with all aluminum construction,
tubes shall conform to ASTM B 210M ASTM B 210, alloy 1100 and aluminum alloy conforming to chemical requirements
of ASTM B 209M ASTM B 209; alloy 7072 shall be used for the fins and end sheets. Fins shall be soldered or mechanically
bonded to the tubes and installed in a metal casing. Coils shall be tested after assembly at pressure specified
in ASHRAE 15 & 34 for the refrigerant employed in the system. [After testing of the heat pipe coils, coils
shall be dried to remove free moisture, and capped to prevent entrance of foreign matter.]
2.6.2.3 Refrigerants
Refrigerants shall be one of the hydrocholrofluorocarbon or hydrofluorocarbon gases. Refrigerants shall have
number designations and safety classifications in accordance with ASHRAE 15 & 34. Refrigerants shall meet
the requirements of AHRI 700 as a minimum. Refrigerants shall have an Ozone Depletion Potential (ODP) of less
than or equal to 0.05 and shall be in compliance with pertinent EPA regulations. The unit shall be factory leak
tested and dehydrated, as specified in Section [23 64 26 CHILLED, CHILLED-HOT, AND CONDENSER WATER PIPING SYSTEMS]
[23 23 00 REFRIGERANT PIPING] [[_____]].
2.6.3 Fans (Solid Desiccant System) For Supply and Regeneration
The unit shall be equipped with two belt driven backward inclined blowers. A drive belt rated for minimum 150%
of motor horsepower shall be used on each motor. The supply fan motor shall have sheaves for air balancing.
The motors shall be nominal 3500 RPM, NEMA B with open dripproof housings and a minimum service factor of 1.15.
2.6.4 Heating System (Solid Desiccant System)
Regeneration and process heating coils shall be of the finned tube type, and shall be constructed of 13 mm 1/2
inch OD seamless copper tube mechanically bonded to aluminum fins. The coils shall include a flanged, heavy-gauge,
galvanized steel housing for mounting to the unit. The coils shall be rated for 1135 kPa 150 psig.
2.6.5 Filters (Solid Desiccant System)
Outside air inlets and return air plenums shall be equipped with 50 mm 2 inch, 30% minimum efficiency filters.
Filters shall be pleated and disposable.
2.6.6 Indirect Evaporative Cooling System (Solid Desiccant System)
NOTE: Where water is of high hardness (alkalinity), provisions shall be made
to facilitate automatic or manual blowdown to reduce solids build-up. Alternatively,
water should be softened prior to use as make-up for the evaporative cooling
system.
Evaporative cooling shall be used to indirectly cool the supply air. The system shall include: An evaporative
cooling media of cellulose paper impregnated to resist degradation and PVC piping.
2.6.7 Gas Fired Boiler (Solid Desiccant System)
NOTE: Boiler regeneration capacity, as determined by the manufacturer, may
be based on the regeneration capacity required under "design day" conditions,
or 1% or 2.5% summer outdoor design conditions. The supporting rationale behind
such sizing is that the specific humidity of the air leaving the desiccant will
be fairly constant over variable outdoor conditions. The boiler will substantially
regenerate the desiccant at relatively high outdoor dry-bulb temperatures and
specific humidity ratios, while full-capacity regeneration at lower outdoor
dry-bulb temperatures and specific humidity ratios will still produce a process
air stream with a specific humidity ratio comparable to that achieved at outdoor
conditions of higher dry-bulb temperature and specific humidity ratio. This
approach minimizes the expense of a higher capacity boiler, boiler short-cycling
at light dehumidification loads and the unnecessary expense of excessive dehumidification.
If a higher capacity boiler is required, the designer should discuss this with
the manufacturer and investigate the possibility of modulating control of regeneration
heat (which will be simpler to obtain with an external, rather than internal,
heat source for regeneration).
The boiler shall be a gas-fired water heater suitable for delivering fluid temperatures of 99-104 degrees C 210-220
degrees F. It shall have a copper tube exchanger and cast iron wet walls. It shall be complete with all controls,
including an automatic gas valve, automatic pilot spark ignition system, power draft inducer, supply water control
temperature sensor, and suitable safety controls. The hydronic system shall include properly sized diaphragm
type expansion tank. Diaphragm shall be flexible butyl securely attached to inner tank wall. Maximum allowable
working pressure shall be at least 791 kPa 100 psig, and 116 degrees C 240 degrees F temperature.
2.6.8 Circulating Pumps (Solid Desiccant System)
Evaporative cooling pump shall be a submersible pump with a hooded intake, polypropylene screen, and thermal
overload protection. Boiler pump shall be an in-line close coupled single stage centrifugal.
2.6.9 Refrigeration Section (Solid Desiccant System)
NOTE: The addition or elimination of the refrigeration section to a rotary
wheel desiccant should not hinder the designer from selecting additional refrigeration
equipment downstream or upstream (pre-cooling coil) of the desiccant unit.
The designer can choose this option, but should view the desiccant system as
part of the total air delivery system.
The refrigeration loop shall be integral to the unit, and factory charged. The condenser section shall provide
the heat required to regenerate the desiccant rotor, and the evaporator section shall provide additional cooling/dehumidification.
Refrigerants shall be one of the hydrocholrofluorocarbon or hydrofluorocarbon gases. Refrigerants shall have
number designations and safety classifications in accordance with ASHRAE 15 & 34. Refrigerants shall meet
the requirements of AHRI 700 as a minimum. Refrigerants shall have an Ozone Depletion Potential (ODP) of less
than or equal to 0.05 and shall be in compliance with EPA regulations. The unit shall be factory leak tested
and dehydrated, as specified in Section [23 64 26 CHILLED, CHILLED-HOT, AND CONDENSER WATER PIPING SYSTEMS] [
23 23 00 REFRIGERANT PIPING] [or] [Section 23 82 02.00 10 UNITARY HEATING AND COOLING EQUIPMENT].
2.6.10 Conditioner unit (Liquid Desiccant System)
NOTE: Lithium chloride salt solution is now being used in liquid desiccant
systems. If another solution is to be used, the designer must edit those parts
that make reference to lithium chloride solution to reflect the properties of
the solution used.
The conditioner unit shall consist of a watertight housing containing the sump, inlet air diffusers, desiccant
solution-to-air contact surface, desiccant solution distribution system and mist eliminator system; and a free
standing pump assembly with tank, vertical seal-less solution pump and motor, and full-flow solution filter screen.
The housing and pump tank shall be fabricated from corrosion resistant materials resistant to the desiccant solution.
Internal parts shall be made of cupronickel or nonmetallic corrosion-proof materials. The desiccant solution
pump and all other wetted parts shall be made with corrosion resistant materials. Fiberglass reinforced plastic
surfaces shall be pigmented and U.V. stabilized for exposure to direct sunlight.
2.6.10.1 Humidity Conditioning
The humidity conditioning system shall be of the liquid desiccant type. The system shall be capable of simultaneous
air cooling and dehumidification as indicated on the drawings. The system shall automatically, fully modulate
the usage of conditioner coolant and regenerator heat to match the system cooling and dehumidification loads.
The humidity conditioning system shall deliver air containing not more than 5 microorganisms per 0.3 Cu. m 10
Cu. Ft, as measured by the Six-Plate Andersen Sampling Method, provided the supply air to the system contains
not more than 100 organisms per 0.3 Cu. m 10 Cu. Ft.
2.6.10.2 Desiccant Solution
The desiccant solution shall be stable and non-toxic and the desiccant shall not exist in the vapor phase in
the conditioned air stream. The maximum loss rate of desiccant to the conditioned air stream shall not exceed
two parts lithium per billion parts air, by weight. The manufacturer shall provide the end user with analysis
and recommendations for maintenance of the desiccant solution six times yearly, free of charge, for the life
of the equipment.
2.6.11 Conditioner Cooler (Liquid Desiccant System)
The conditioner desiccant solution cooler shall be of the plate-and-frame type, with carbon steel frame carrier
bars and tiebolts; titanium plates and nitrite or EPDM gaskets. The solution heater shall be supplied complete
with heating fluid control valve. The heat exchangers shall be shipped loose for field installation.
2.6.12 Regenerator (Liquid Desiccant System)
The regenerator units shall each consist of a watertight housing containing the sump, inlet air diffusers, desiccant
solution-to-air contact surface, desiccant solution distribution system and mist eliminator system; and a free
standing pump assembly with tank, vertical seal-less solution pump and motor, and full-flow solution filter screen.
The housing and pump tank shall be fabricated of corrosion resistant materials resistant to the desiccant solution.
Internal parts shall be made of cupronickel or nonmetallic corrosion-proof materials. The desiccant solution
pump and all other wetted parts shall be made with corrosion resistant materials resistant to the desiccant solution.
Fiberglass reinforced plastic surfaces shall be pigmented and U.V. stabilized for exposure to direct sunlight.
2.6.12.1 Humidity Conditioner
The humidity conditioning system shall consist of separate conditioning and desiccant regeneration units providing
complete separation of conditioned and regeneration air streams. The manufacturer shall guarantee that there
will be no cross-leakage of conditioner and regenerator air streams under any circumstances.
2.6.12.2 Fan Assembly
The regenerator shall be supplied with a separate field-mounted fan and fan box assembly, consisting of housing,
forward-curved fan motor, and drive. The fan wheel shall be made of steel. The fan box shall be made of galvanized
steel. The fan wheel and fan box interior shall be heresite coated. The fan box exterior shall be painted with
a prime and finish coat of industrial-grade acrylic machine enamel.
2.6.12.3 Equipment Location
The equipment shall be so designed that the conditioner and regenerator units need not be installed in the same
location, and may be located wherever convenient. Where units are installed outside, weatherproof insulation
is required and adequate freeze protection for water, steam, and condensate piping is required.
2.6.13 Regenerator Heater (Liquid Desiccant System)
The regenerator solution heater shall be of the plate-and-frame type, with carbon steel frame carrier bars and
tiebolts; titanium plates and nitrite or EPDM gaskets. The solution heater shall be supplied complete with heating
fluid control valve. The heat exchangers shall be shipped loose for field installation.
2.6.14 Level Control (Liquid Desiccant System)
The level control panel shall consist of safety interlock pressure switch, unit pressure drop indicator, bubbler
type supply pneumatics, P/I transducer, I/P transducer, and PID single-loop controller, all contained in a NEMA
12 enclosure. The level control panel shall be shipped mounted to the unit.
2.6.15 Filter Screening (Liquid Desiccant System)
The unit shall be equipped with noncorrosive diffuser and filtering system capable of filtering any droplets
in the air stream and diffusing the stream for uniform airflow distribution.
2.6.16 Freestanding Pump Assemblies (Liquid Desiccant System)
The conditioner and regenerator shall be equipped with a freestanding seal-less pump and motor. The pumps shaft
shall be made with an corrosion resistant materials suitable for the desiccant solution and all other wetted
parts of vinylester FRP, or equal.
2.6.17 Make Up Water System (Liquid Desiccant System)
The unit shall be equipped with piping, valving, and controls to automatically maintain solution level in the
conditioner section. The level control panel shall consist of a safety interlock pressure switch, unit pressure
drop indicator, bubbler tube ("type" is indicated above) supply pneumatics, P/I transducer, I/P transducer, and
PID single-loop controller, all contained in a NEMA 12 enclosure. The level control panel shall be shipped mounted
to the unit.
2.6.18 Conditioner Fan (Liquid Desiccant System)
The unit shall be equipped with a conditioner fan only to the extent necessary to supply static pressure to existing
equipment, or if used as a stand alone unit, as specified in Section 23 00 00 AIR SUPPLY, DISTRIBUTION, VENTILATION,
AND EXHAUST SYSTEM.
2.6.19 Regeneration Fan (Liquid Desiccant System)
The regeneration fan shall be supplied with a separate field-mounted fan and assembly rated for the requirements
of the regeneration system. The fan and assembly shall be of such design and construction to be resistant to
the chemicals within the regenerator, as specified in Section 23 00 00 AIR SUPPLY, DISTRIBUTION, VENTILATION,
AND EXHAUST SYSTEM.
2.7 SUPPLEMENTAL ACCESSORIES/SERVICES
2.7.1 Nameplates
Each major component of equipment shall have the manufacturer's name, address, type or style, and catalog or
serial number on a plate securely attached to the item of equipment. Nameplates shall be secured to the cabinet
of dry desiccant units, indicating the equipment enclosed within the cabinet behind the nameplate. Cabinets
shall have hinged panels, as specified, to facilitate maintenance of the component described on the nameplate
secured to the cabinet.
2.7.2 Drain and Makeup Water Piping
NOTE: All drain and makeup water piping should be indicated on the drawings.
Piping shall comply with the requirements of Section 22 00 00 PLUMBING, GENERAL PURPOSE. Drains which connect
to sanitary sewer system shall be connected by means of an indirect waste.
2.7.3 Steam Piping and Accessories
Steam piping and accessories shall be provided and installed in accordance with Section 23 52 00 HEATING BOILERS.
2.7.4 Conditioner Solution Concentration
Provide the conditioner solution concentration capable of maintaining the humidity level specified on the drawings.
2.7.5 Automatic Controls
NOTE: Change paragraph as required to coordinate the central equipment controls
with the air-side system controls. In projects where this specification is
intended to produce control equipment for existing air-side systems, this paragraph
will be edited to secure controls to match existing controls and to properly
integrate the specified controls into the existing temperature control system.
Designer will be required to put a sequence of control for each cooling tower
fan, chilled water pump, condenser water pump, etc. on the contract drawings.
One control measure recommended for consideration by the designer for solid
desiccant units is a bypass damper arrangement whereby desiccant unit components
are de-energized when the desiccant unit is not performing dehumidification,
and a damper in the process air ductwork is closed. At the same time, a (bypass)
damper in the outside air ductwork is open so that a central station air handling
unit will not have to draw minimum (or economizer cycle) outside air quantities
through the desiccant unit; i.e., outside air will bypass the desiccant unit
on its way to the central air handler. When dehumidification is called for,
the bypass damper will close and the damper in the process air ductwork will
open, which will enable desiccant unit components to be energized (the dampers
can be near one another and set to assume reversible and opposite positions
through mounting on a common jackshaft). This control has numerous advantages:
it reduces aggregate flow through desiccant unit filters and rotors, extending
their useful lives; it reduces fan head pressure loss from particulate accumulation
on filters and rotors, simultaneously reducing desiccant fouling and accompanying
loss of dehumidification capacity; also, it reduces electrical energy consumption
since the desiccant unit process air fan will not (and cannot) operate to move
air through the desiccant unit to the central station air handler when dehumidification
is not called for. The differential on the controls must be set; however, so
that dampers and desiccant unit components do not short cycle.
Automatic controls for the specified desiccant system shall be provided with the desiccant equipment. These
controls shall operate automatically to balance the equipment capacity with the load on the air conditioning
system, and shall be fully coordinated with and integrated into the [temperature control system specified in
Sections 23 00 00 AIR SUPPLY, DISTRIBUTION, VENTILATION, AND EXHAUST SYSTEM and 23 09 23 DIRECT DIGITAL CONTROL
FOR HVAC AND OTHER LOCAL BUILDING SYSTEMS][existing air-conditioning system].
PART 3 EXECUTION
3.1 EXAMINATION
After becoming familiar with all details of the work, perform verification of dimensions in the field, and advise
the Contracting Officer of any discrepancy before performing any work.
3.2 INSTALLATION
All work shall be performed in accordance with the manufacturer's published diagrams, recommendations, and equipment
warranty requirements.
3.2.1 Equipment
NOTE: Designer will determine, in the initial stages of design, the approximate
distances required for maintenance clearances of all new equipment. he maintenance
clearances will be used in determining the final layout of the equipment. For
installations where noise and vibration transmission to the building must be
reduced, the maximum tolerable transmissibility, in percent, should be determined
and the blank filled with the appropriate value. When it is not necessary to
specify the percent of transmissibility, the item in the brackets will be deleted
and brackets removed. Recommended transmissibility in percentages is: 10 percent
for equipment mounted in very critical areas; 10 to 20 percent for critical
areas; and 20 to 40 percent for noncritical areas. The drawings should be checked
to ensure that all structural and equipment connection factors and the conditions
surrounding the equipment to be provided with the vibration isolation units
favorably influence the effectiveness of the isolators. Where many items of
equipment require different transmission values, based on the equipment location,
the specification may be revised to indicate the appropriate values on the drawings.
Necessary supports shall be provided for all equipment, appurtenances, and pipe as required, including frames
or supports. Housings shall be isolated from the building structure. If mechanical vibration isolators are
not provided, vibration absorbing foundations shall be furnished. Each foundation shall include isolation units
consisting of machine and floor or foundation fastenings, together with intermediate isolation material. Other
floor-mounted equipment shall be set on not less than a 150 mm 6 inch concrete pad doweled in place. Concrete
foundations for floor mounted pumps shall have a mass equivalent to three times the weight of the components,
pump, base plate, and motor to be supported. In lieu of concrete pad foundation, concrete pedestal block with
isolators placed between the pedestal block and the floor may be provided. Concrete pedestal block shall be
of mass not less than three times the combined pump, motor, and base weights. Isolators shall be selected and
sized based on load-bearing requirements and the lowest frequency of vibration to be isolated. Isolators shall
limit vibration to [_____] percent at lowest equipment rpm. Lines connected to pumps mounted on pedestal blocks
shall be provided with flexible connectors. Foundation drawings, bolt-setting information, and foundation bolts
shall be furnished prior to concrete foundation construction for all equipment indicated or required to have
concrete foundations. Concrete for foundations and concrete-structured or cast-cooling towers shall be as specified
in Section 03 31 00.00 10 CAST-IN-PLACE STRUCTURAL CONCRETE. Equipment shall be properly leveled, aligned, and
secured in place in accordance with manufacturer's instructions.
3.2.2 General Piping, Valves, and Duct Installation
All piping, valve, and duct installation shall be made in accordance with the desiccant equipment manufacturer's
recommendation or in accordance with Sections 23 00 00 AIR SUPPLY, DISTRIBUTION, VENTILATION, AND EXHAUST SYSTEM[,
23 64 26 CHILLED, CHILLED-HOT, AND CONDENSER WATER PIPING SYSTEMS][23 23 00 REFRIGERANT PIPING][[_____],] and
22 00 00 PLUMBING, GENERAL PURPOSE.
3.2.3 Pipe Color Code Marking
NOTE: Designer will coordinate color code marking with Section 09 90 00. Color
code marking for piping not listed in Table I of Section 09 90 00, will be added
to the table.
Color code marking of piping shall be as specified in Section 09 90 00 PAINTS AND COATINGS.
3.3 MANUFACTURER'S FIELD SERVICE
Provide the services of a factory-trained representative for [_____] days. The representative shall advise on
the proper operation and servicing of the equipment and make any adjustments necessary to insure full compliance
with design criteria.
3.4 DEMONSTRATIONS
Conduct a training course for the operating staff as designated by the Contracting Officer. The training period
shall consist of a total [_____] hours of normal working time and start after the system is functionally completed
but prior to final acceptance tests. The field instructions shall cover all of the items contained in the Operation
and Maintenance Manuals as well as demonstrations of routine maintenance operations.
3.5 PERFORMANCE TESTS
NOTE: Performance data should be provided at other than or in addition to "design
day" conditions, or the 1% or 2.5% outdoor "Summer Design Data - Air Conditioning"
dry-bulb (Db) temperature conditions defined in UFC 3-400-02. Peak humidity
loads arising from ventilation or makeup air occur when the outdoor specific
humidity (Gr./lb) is highest, frequently at dry-bulb temperature conditions
other than design day, or 1% or 2.5% outdoor summer design dry-bulb temperature
conditions. Also, there may be significantly more hours occurring annually
at conditions of higher outdoor specific humidity than at higher outdoor dry-bulb
temperature. However, dry-bulb temperature can be important, as at times during
the summer when the regeneration heating required is less than capacity due
to a relatively low outdoor dry-bulb temperature that is coincident with a relatively
high outdoor specific humidity. The foregoing is predicated on the assumption
that outside air would be used as the source of process air and regeneration
air. Obviously, other arrangements are possible, such as facility exhaust air
providing the source of regeneration air, or a mixture of both return and outside
air, providing the source for process air. Designer needs to indicate the range
of humidities the equipment should cover in the plans or specifications.
Before each desiccant system is accepted, tests to demonstrate the general operating characteristics of all equipment
shall be conducted by a registered professional engineer or an approved manufacturer's startup representative
experienced in system startup and testing, at such times as directed. The tests shall measure quantities listed
below. Tests shall cover a period of not less than [_____] days for each system and shall demonstrate that the
entire system is functioning in accordance with the drawings and specifications. Corrections and adjustments
shall be made as necessary and tests shall be re-conducted to demonstrate that the entire system is simultaneously
functioning as specified. A report shall be prepared for each desiccant system, including the information outlined
below. Data for the tests shall be taken at least three different times at outside wet-bulb temperatures which
are at least 3 degrees C 5 degrees F apart.
3.5.1 Liquid Desiccant System
a. Date and outside weather conditions (at least two parameters to define the state of the outside air:
DB (dry bulb temperature), Gr./LB (grains water per LB dry air), Wb (wet bulb temperature), relative
humidity).
b. The load on the system based on the following:
(1) CFM entering the system (Process and Regeneration).
(2) Conditioner side - entering air conditions (Db, Gr./LB).
(3) Conditioner side - discharge air conditions (Db, Gr./LB).
(4) Conditioner side - coolant entering temperature.
(5) Regenerator side - entering air conditions (Db, Gr./LB).
(6) Regenerator side - discharge air conditions (Db, Gr./LB).
(7) Regenerator side - heat source temperature (Btu/hr).
(8) Running current, voltage and proper phase sequence for each phase of all motors.
(9) The actual on-site setting of all operating and safety controls.
3.5.2 Solid (Wheel) Desiccant System:
a. Date and outside weather conditions (at least two parameters to define the state of the outside air:
DB, Gr./LB, Wb, relative humidity).
b. The load on the system based on the following:
(1) CFM entering the system (Process and Regeneration).
(2) Process side - entering air conditions (Db, Gr./LB).
(3) Process side - discharge air conditions (Db, Gr./LB).
(4) Process side - post coolant capacity (tons).
(5) Regenerator side - entering air conditions (Db, Gr./LB).
(6) Regenerator side - discharge air conditions (Db, Gr./LB).
(7) Regenerator side - heat source capacity (Btu/hr).
(8) Running current, voltage and proper phase sequence for each phase of all motors.
(9) The actual on-site setting of all operating and safety controls.
3.6 INSPECTIONS
NOTE: It is strongly suggested that the customer obtain a service contract
on these units (solid and liquid) to insure proper operation of the desiccant.
The manufacturer of the liquid desiccant system shall supply, free of charge, testing of solution samples sent
to them by the customer every two months for the life of the equipment. The manufacturer of each type system
shall inspect the systems after one year of operation to insure the systems are operating properly.
3.7 CLEANING AND ADJUSTING
Wipe equipment clean, with all traces of oil, dust, dirt, or paint spots removed. Provide temporary filters
for all fans that are operated during construction, and install new filters after all construction dirt has been
removed from the building. Maintain system in this clean condition until final acceptance. Bearings shall be
properly lubricated with oil or grease as recommended by the manufacturer. Belts shall be tightened to proper
tension. Control valves and other miscellaneous equipment requiring adjustment shall be adjusted to the setting
indicated or directed. Fans shall be adjusted to the speed indicated by the manufacturer to meet specified conditions.