DRY ROOMS IMPORTANCE AND APPLICATIONS Manufacturers dealing with moisture-sensitive or hygroscopic products often find significant productivity enhancements by switching from glove boxes or inert chambers to dry rooms. This approach serves industries such as lithium battery production and pharmaceutical diagnostics. Harris Environmental’s dry rooms offer several unique advantages:
Vapor-tight construction minimizes moisture intrusion from personnel and makeup air.
A turnkey solution ensures a single-source guarantee meeting room specifications.
Modular wall panels simplify room expansion or relocation.
Experience ranges from small 100 sq. ft. rooms to larger 14,000 sq. ft. rooms.
Heat reclamation from conditioning systems helps lower energy expenditures.
Standard D/H Series skidded systems are available from 500 CFM.
CUSTOMIZED DRY ROOM DESIGN Our design approach focuses on your specific requirements rather than offering a one-size-fits-all solution.
Key factors in dry room design include:
The number of personnel operating within the room.
Desired temperature and humidity control standards.
Available construction space.
Sensible internal heat load and room exhaust.
The desired humidity and personnel moisture loads define the size of the dehumidification air handling system needed. With precise design, desiccant dehumidification systems can achieve air delivery to a minimum of .47 gr/lb. This results in operating levels as low as 1% RH.
When floor space allows, placing a Harris D/H series skid next to the dry room minimizes moisture infiltration in the conditioning system and reduces the length of ductwork. If this layout isn't feasible, dehumidification systems can be mounted on skids and placed above the dry room within the main building or even on rooftops.
An illustrative diagram below shows a typical production dry room with two D/H series systems used.
Use the key below to identify components
A Return air plenum wall & barrier reduces high moisture areas by sweeping air across the entire room.
B Makeup air duct.
C Reactivation exhaust through building wall or roof, providing low-grade heat in the winter.
D Redundant D/H systems offer 50% to 100% system backup for production dry rooms.
E Harris custom D/H Series dehumidification system with desiccant wheel and all heating/cooling elements for the dry room.
F Water-cooled condensing unit piped to a remote dry cooler. Air-cooled remote units are also available.
G All-welded aluminum ducting prevents moisture infiltration or leakage.
H Harris 3" modular wall panels with smooth white aluminum skin on both sides.
I Airlocks for entry/exit and gowning for personnel when also a clean room.
J Dry air supply ducts to machine enclosures delivering ultra-dry air to critical processes.
&#;DRYWARE&#; DDC CONTROL = SIMPLIFIED SYSTEM MANAGEMENT The Harris &#;Dryware&#; touch-screen control system replaces traditional mechanical interfaces and relay logic, offering comprehensive access to all D/H Series functions through a single interactive touch-screen.
This system enables worldwide service access to our dry rooms and can be customized or expanded as needed. The Windows-based software allows graphical monitoring of room variables like temperature, coil temperatures, compressor discharge temperature, and dewpoints. With dedicated modem access, Harris can provide online consultation and troubleshooting to reduce maintenance expenses and ensure optimal system performance.
DRY ROOM SELECTION PROCESS When users complete the provided selection card, we gather sufficient information to offer a tailored Harris dry room proposal. Our extensive expertise allows us to prefabricate many components, expediting the entire construction timeline.
HARRIS 'SINGLE SOURCE QUALITY GUARANTEE' Managing multiple manufacturers and contractors requires effort and coordination. With Harris handling the entire process as a turnkey contractor, we take over the design, manufacturing, installation, and startup of the room. Our 'single-source quality guarantee' ensures compliance with temperature and humidity control specifications for one year post-startup.
ABOUT HARRIS ENVIRONMENTAL Harris Environmental Systems has provided turnkey environmental rooms for over 40 years, beginning with cold rooms, incubators, and blood storage rooms for medical research. Since the 1970s, Harris expanded to design low-temperature refrigeration systems and burn-in chambers for the electronics industry. Today, we excel in dry rooms, clean rooms, temperature and humidity cycling rooms, and archival storage vaults, among others. Our expertise is backed by a robust installation team ensuring all components are thoroughly tested and started up for quality assurance.
Dry Room Specifications
GENERAL DESIGN The dry room shall utilize prefabricated, metal-clad panels for all walls and roofs, enabling future expansions or relocations. Supplied and installed by Harris Environmental Systems, the self-contained unit will include all necessary mechanical conditioning equipment, controls, and ductwork, designed to maintain the dry room at 72°F, ±2°, 2% RH (1.8 gr/lb) or drier, as specified by the end user.
SUBMITTALS AND OPERATION MANUAL Submittals will feature shop drawings indicating room dimensions, construction features, electrical wiring diagrams, mechanical system schematics, and vendors' parts lists. The operating and maintenance manual will detail sequential operations, startup and shutdown procedures, with all pertinent control data and schematics.
INSTRUCTION PERIOD Upon completing room installation and startup, the room manufacturer will provide an engineering representative to instruct in the room's operation, covering controls and related systems.
WARRANTY We guarantee the installation and its ability to maintain specified temperature and humidity control levels for one year from the date of startup or customer approval.
Construction of Room Shell
Wall & Roof Panels Wall and roof panels will consist of 3" thick rigid board form isocyanurate urethane or polystyrene with .032" smooth tempered aluminum skins, bonded to the foam core with two-part epoxy. The aluminum surfaces will have a baked epoxy paint and be covered with a strippable polyethylene film to protect against accidental damage.
Panel Fastening System Linear tempered anodized aluminum extrusions will join the panels, ensuring a tight seal. Fastener extrusions will provide closure over the full length of joined sections. All 90° corners and edges of the panels will be sealed with silicone to prevent air and moisture infiltration along cracks.
Floors Floors will comprise the existing surface covered with conductive, vapor barrier material. Conductive tiles will be installed to eliminate static electricity.
Doors & Airlock Standard doors will match wall panel construction, providing a clear opening of 80" high and 36" wide, with a viewing window in each door. Anodized aluminum frames and double gasketing on three sides ensure airtight doors. Oversized and double doors are available upon request. An airlock or vestibule will guard against moisture infiltration, maintaining a positive pressure to prevent entry of outside air.
Mechanical Conditioning System
Design The dry room's conditioning system will consist of: (a) Rotary wheel desiccant dehumidifier, (b) air- or water-cooled condensing units with Copeland semi-hermetic compressors, (c) cooling coils, (d) centrifugal airfoil fans, and (e) filters.
Where possible, placing the conditioning system adjacent to the dry room (excluding condensers or wet coils) reduces leakage possibilities from prolonged ductwork and allows use of the mechanical room as a plenum. If space constraints prevent an adjacent mechanical room, a skidded D/H Series system ensures precise temperature and dewpoint control from a separate location.
Major Components
Desiccant Dehumidifier A rotary wheel composite desiccant dehumidifier achieves a condition of .047 gr/lb. of dry air (-76°F dewpoint), optimizing reactivation energy use compared to other systems. This unit provides continuous dewpoint control, minimizing risks of desiccant channeling, attrition, or carryover. Reactivation energy options include electric, indirect fired gas, or steam (50 PSIG minimum).
Condensing Unit Air- or water-cooled condensing units include semi-hermetic Copeland compressors, spring mounted for vibration isolation. Remote placement of air-cooled condensers prevents moisture infiltration. Each unit features high-low pressure control, suction/discharge vibration mitigation, fusible plugs, liquid line dryers, moisture indicating sight glasses, suction line filters, magnetic contactors, and other safety mechanisms. Capacity control is maintained via compressor unloading, hot gas bypass, EPR valves, or compressor shutdown.
Cooling Coils Constructed of copper tubes and aluminum fins, the housing will be aluminum. Design parameters include a minimum of eight fins per inch and four-row depth, maintaining air velocity below 500 FPM.
Fans Centrifugal airfoil design fans will be utilized, belt-driven as applicable to minimize noise. Fractional horsepower motors may be direct drive. Process dry air fans will be mounted on vibration isolators.
Refrigeration Piping Through careful engineering, all refrigerant lines will use ACR-type hard-drawn copper tubing, silver-brazed for discharge lines. Suction lines, designed for horizontal velocities of 500-750 FPM and vertical velocities of 1000-1500 FPM, will employ proper “P” traps where needed. Liquid lines allowing a maximum 2 PSIG pressure drop will utilize Armstrong Armaflex insulation.
Instrumentation and Control Systems
Humidity Control and Recording Humidity will be monitored using an aluminum oxide current inducing sensor, recorded with a dual pen temperature and humidity recorder. High humidity alarms will trigger any backup dehumidification equipment automatically. Optional chilled mirror dewpoint sensors with digital readouts are available. Comprehensive Harris “Dryware” DDC controls offer full system monitoring as an option.
Temperature Control Temperature is regulated via refrigeration or reheat, with a PID controller modulating based on actual vs. setpoint conditions. Automatic high/low temperature alarms enhance reliability.
Ceiling Plenum and Lighting
Air Distribution Utilizing a tee-grid plenum ceiling, uniform air circulation and distribution will include metal perforated air distribution tiles and fire-rated filler tiles. Returns to the conditioning system will go through wall grills or a standoff wall. The plenum also houses lighting troffers.
Lighting Fluorescent lighting fixtures will provide even 70-footcandle illumination throughout the room. Fixture designs will include door-mounted acrylic lenses, with options for incandescent or high-intensity discharge lighting available.
Room Services
Electrical The electrical contractor will handle the entry of electrical supply for lighting, condensing units, and dehumidifiers.
Water Any necessary water for water-cooled condensing units will be supplied by the end user. Discharge and condensate pan drainage within 5 ft will be the responsibility of the end user or general contractor.
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