Lennox Humiditrol® Whole-Home Dehumidification System

Model Number Identification

The model number follows the format EDA-XXX C. 'EDA' signifies Enhanced Dehumidification Accessory (Whole Home Dehumidification System). 'XXX' represents the nominal capacity: 024 for 2 tons, 036 for 3 tons, and 060 for 5 tons. 'C' indicates the cabinet width: 'B' for 17-1/2 inches, 'C' for 21 inches, and 'D' for 24-1/2 inches. The letter designation in the model number will physically match gas furnaces with the same letter designation in their model number.

Feature Highlights

• 1. Heavy Gauge Steel Cabinet
• 2. Low Voltage Electrical Inlet
• 3. Fully Insulated Cabinet
• 4. Dehumidification Coil
• 5. Sweat Connections
• 6. Dual Refrigerant Diverter Valves
• 7. 3-Way Diverter Valve Actuator

Overview

The EDA unit is installed in an HVAC system downstream from the indoor coil or air handler. In dehumidification mode, the coil becomes an extension of the outdoor coil and rejects heat into the indoor air stream. This dehumidification mode allows significantly improved control of the humidity in the conditioned space without overcooling the space. The EDA unit includes a set of 3-way diverter valves which route refrigerant through the EDA coil (Dehumidification ON), or which cause the refrigerant to bypass the EDA coil (Dehumidification OFF).

Cabinet

• Low-profile design allows easy installation in upflow or horizontal applications.
• Heavy-gauge, cold rolled steel construction.
• Pre-painted cabinet finish.
• Flanges provided on supply air opening for ease of plenum connection.
• Slots on perimeter of inlet opening help facilitate secure connection to indoor coil / air handler flanges.
• Low voltage electrical inlet (for refrigerant valve actuator) provided on front of cabinet.
• Fully insulated with foil-faced insulation.

Components

• Dehumidification Coil: Features durable copper tubing, ripple-edged aluminum fins with lanced fins for maximum exposure to the air stream, and rifled tubing for superior refrigerant heat transfer. Twin coil construction (A-configuration) is used for 036C and 060D models, while single slab coil construction is used for the 024B model.
• Sweat Connections: High-pressure testing ensures leak-proof construction.
• Combination Check/Flow Limiting Piston: Furnished for field installation, this component prevents refrigerant from flowing into inactive components when the EDA coil is inactive.
• Dual Refrigerant Diverter Valves: Heavy-duty valves control refrigerant flow depending on the operating mode.
• 3-Way Diverter Valve Actuator: Controls the operation of refrigerant valves during EDA operation. It is 24VAC and has a three-position actuator shaft for maintenance (Cooling, Evacuate, or Bypass).
• Outdoor Fan Relay and Wiring Harness: Required when the EDA is used with outdoor units featuring multi-speed outdoor fans.

Approvals and Warranty

Approvals

• Units are CSA certified according to UL-207 and CSA C22.2 No. 14.3 standards.
• ISO 9001 Registered Manufacturing Quality System.

Warranty

• All covered components:
  • Limited five years in residential installations.
  • Limited one year in non-residential installations.

NOTE - Refer to Lennox® Basic Limited Warranty at www.Lennox.com for additional details.

NOTE - Lennox warranties do not cover damage or defect resulting from operation with system components (indoor unit, outdoor unit, and refrigerant control devices) which do not match or meet the specifications recommended by Lennox. This unit is intended to operate with specific furnaces and air handlers only. See System Decision Tree on page 12.

Applications

NOTE - The Humiditrol® Whole Home Dehumidification System is not applicable to variable-capacity outdoor units.

• Designed for use with Lennox R-410A outdoor unit expansion valve systems only, matched with specific furnaces or air handlers.
• Refer to System Decision Tree on page 13 for available matches.
• Suitable for indoor installations in either upflow or horizontal applications only.
• Height, space, and airflow restrictions, or unit stability in a stacked configuration, may limit the use of downflow applications.

NOTE - Refer to Installation Instructions supplement "Installing Humiditrol® EDA Unit in Downflow Configuration" for more details.

NOTE - Sensible to Total Ratios are not available for downflow applications.

Required Controls

NOTE - Third-party thermostats are not compatible with the EDA Dehumidification System. One of these Lennox thermostats with integrated EDA control logic is required for proper operation.

S40 Smart Wi-Fi Thermostat

Part of the Lennox® Residential Communicating Control System. Recognizes and connects to all Lennox® Communicating products to automatically configure and control the heating/cooling system. Features include user-specified settings for comfort, performance, and efficiency; recognition of model and serial numbers for simplified setup; compatibility with Lennox Smart Room Sensors, Wireless Extenders, and Smart Air Quality Monitor; smart home automation (Amazon Alexa®, Google Assistant, Control4®, Building36®); service alerts and reminders; Wi-Fi remote monitoring and adjustment via app; Lennox Smart Technician App for installers; Service Dashboard for online monitoring and diagnostics; easy-to-use touchscreen; scheduled maintenance alerts; 7-inch high-definition color display; ability to control conventional outdoor units; installer setup screens for quick configuration and testing; serial communications bus (RSBus); standard 4-wire unshielded thermostat wiring; High Definition Color Display with Subbase and wallplate.

NOTE - See the Lennox® S40 Thermostat Product Specifications bulletin for more information.

NOTE - A Lennox® Communicating indoor unit (furnace or air handler) is required for proper operation of the Lennox® Communicating Thermostat with a conventional outdoor unit.

NOTE - The Humiditrol® Enhanced Dehumidification Accessory is not Lennox® Communicating but can easily be added and controlled by the Lennox® Thermostat. Dehumidify settings are adjustable from 40 to 60% relative humidity (RH).

E30 Smart Wi-Fi Thermostat

Wi-Fi enabled, electronic 7-day, universal, multi-stage, programmable, touchscreen thermostat. Features 3 Heat/2 Cool, Auto-changeover. Controls dehumidification during cooling mode and humidification during heating mode. Offers enhanced capabilities including humidification/dehumidification/dewpoint measurement and control, Humiditrol® control, and equipment maintenance reminders. Features a 7-inch color touchscreen, LCD display with backlight showing current/set temperature, time, indoor humidity, system status, and outdoor temperature (optional sensor required). Includes Smooth Setback Recovery, compressor short-cycle protection (5 minutes), up to four schedules, Schedule IQ™, One-Touch Away Mode, and Smart Away™ geo-fencing. Supports Wi-Fi remote monitoring and adjustment, and smart home automation (Apple HomeKit™, Amazon Alexa®, Google Assistant, IFTTT). Service Dashboard for monitoring. High Definition Color Display with Subbase, Smart Hub Controller, and wallplate.

NOTE - See the E30 Smart Wi-Fi Thermostat Product Specifications bulletin for more information.

Optional Accessories

CS7500 Touchscreen Thermostat

Electronic 7-day, universal, multi-stage, programmable, touchscreen thermostat. Features 4 Heat/2 Cool, Auto-changeover, Dual-fuel control with optional outdoor sensor. Controls dehumidification during cooling mode and humidification during heating mode. Offers enhanced capabilities including humidification/dehumidification/dewpoint measurement and control, Humiditrol® control, and equipment maintenance reminders. Easy-to-use, menu-driven with a back-lit LCD touchscreen.

NOTE - See the CS7500 Thermostat Product Specifications bulletin for more information.

CS7500 Commercial 7-Day Programmable Thermostat

Electronic 7-day, universal, multi-stage, programmable, touchscreen thermostat. Features 4 Heat/3 Cool, Remote Indoor Temperature Sensing with Averaging, Outside or Discharge Air Temperature Display, Occupancy Scheduling with Economizer Relay Control, and Away mode. Offers enhanced capabilities including humidification/dehumidification/dewpoint measurement and control, Humiditrol® control, and notifications/reminders. Includes Performance reports and Economizer relay control. Easy-to-use, menu-driven with a back-lit LCD touchscreen.

NOTE - See the CS7500 Commercial Thermostat Product Specifications bulletin more information.

Remote Outdoor Temperature Sensor

Used with Lennox® Communicating Thermostats (E30, M30, CS7500). Allows thermostat to display outdoor temperature when installed outdoors. NOTE - Sensor is required for Humiditrol® applications. NOTE - The outdoor sensor is furnished as standard with Lennox® Communicating outdoor units, optional for conventional units.

Required Components

Insulation and Piping Kit

Kit includes all necessary piping, fittings, and insulation required for EDA installation. NOTE - Some model match-ups require a charge compensator to maintain the proper amount of refrigerant circulating in the system. The compensator stores excess refrigerant when the EDA coil is active and returns it to the system during normal cooling or heating operations. Charge compensator and related piping/insulation are furnished with certain kits depending on the system match-up.

Relay Kit

Required when used with CBA27UHE air handlers.

Transformer

A 75VA, 24VAC indoor unit transformer is required when the EDA unit is installed with a two-stage heat pump system.

Sequence of Operation

Cooling Cycle With EDA Active

Dehumidification mode begins when the room thermostat's cooling demand has been satisfied, but the dehumidification setting has not. The room thermostat signals the EDA unit's diverter valve actuator. Refrigerant from the outdoor unit enters the EDA unit, passes through the first 3-way diverter valve, and then enters the EDA coil. Here, heat from the warm refrigerant is rejected into the indoor air stream, subcooling the refrigerant. The refrigerant then leaves the coil, passes through the second 3-way diverter valve, and enters the indoor coil expansion valve in a highly subcooled state. During dehumidification, the indoor air blower (and multi-speed outdoor fan, if used) operate at a lower air volume. The warm refrigerant entering the EDA unit from the outdoor unit is subcooled in the EDA coil, entering the expansion valve at a lower-than-normal temperature. Liquid temperatures can be in the 65 to 70°F range, with a 10 to 40°F temperature drop through the EDA coil. The air temperature leaving the indoor coil and entering the EDA coil is normal for the reduced airflow but is warmed as it passes over the EDA coil. Air temperature rise across the EDA can be from 3 to 8°F, depending on operating ambient and air-conditioned space conditions. If cooling demand is satisfied but dehumidify demand exists and room temperature is not more than 2°F below setpoint, the blower operates at reduced airflow while the compressor runs on 2nd stage cooling (two-stage systems only). When outdoor ambient temperatures reach 95°F, system runtime requirements are high, and dehumidification requirements are met without activating this mode. Systems controlled by a CS7500 or Lennox® Communicating thermostat will not allow operation in dehumidification mode when outdoor temperatures exceed 95°F. The system operates more efficiently and avoids unfavorable conditions. When operating in normal cooling (or heat pump heating) mode, temperatures and pressures are the same as a standard heating/cooling system.

Cooling Cycle With EDA Inactive

In normal cooling mode (dehumidification mode OFF), liquid refrigerant from the outdoor unit enters the first 3-way diverter valve. The diverter valve actuator directs refrigerant flow to bypass the EDA coil and flow directly to the indoor unit expansion valve.

Heat Pump Heating Cycle With EDA Inactive

In heat pump heating mode, a system with an EDA unit operates as a conventional heat pump; there is no requirement for EDA unit operation in heat pump heating mode.

Specifications

General Data

Controls - Order Separately

NOTE - Third-party thermostats are not compatible with the EDA Dehumidification System. One of these Lennox thermostats with integrated EDA control logic is required for proper operation.

1 Optional for service diagnostics.

2 Remote Outdoor Temperature Sensor is used with conventional (non-Lennox® Communicating) outdoor units (sensor is furnished with Lennox® Communicating outdoor units). Allows the thermostat to display outdoor temperature. Required in dual-fuel and Humiditrol® applications.

Required Components - Order Separately

4 Required when EDA unit is installed with two-stage heat pump system.

Air Resistance

Dimensions

Diagram Description: The dimensions diagram shows top, front, and side views of the EDA unit with labeled connection points (Liquid Line, Check/Flow Restrictor, To Charge Compensator, Electrical Inlet) and overall dimensions (A, B, C, D, E, F, G) in inches and millimeters for each model.

Typical Installation

Typical installation involves connecting the EDA unit in the supply air plenum, downstream from the indoor coil or air handler. Diagrams illustrate connections for liquid and vapor lines, check/flow restrictor, and charge compensator. The unit can be installed in upflow or horizontal configurations. Important notes include the maximum length for refrigerant lines (12 ft.) and the correct orientation for the check/flow restrictor.

Diagram Description: The installation diagrams show a typical horizontal air handler setup and upflow position. They detail the placement of the EDA unit relative to the indoor unit and outdoor unit, illustrating refrigerant line connections (liquid and vapor), the check/flow restrictor, and the charge compensator. Instructions are provided for connecting these components, including torque specifications for the restrictor and maximum line lengths. The diagrams also show system configurations with and without a charge compensator.

Installation Configurations

The EDA unit can be installed in typical upflow positions with furnaces or air handlers, or in typical horizontal positions. Transitions may be required between the air handler/furnace and the EDA unit, depending on the specific models and installation type. The EDA coil itself is not position sensitive as long as correct airflow direction is maintained.

Diagram Description: The installation configuration diagrams illustrate two primary setups: a typical upflow position with a furnace and an upflow air handler, and a typical horizontal position with a furnace. These diagrams show the placement of the EDA unit relative to other HVAC components and indicate airflow direction. Notes specify that transitions are not furnished and must be field fabricated, and that a transition is required between the indoor coil and EDA if the EDA-060D model is used with a small profile furnace.

System Decision Tree

The System Decision Tree guides the selection process. It starts by checking for zoning application and thermostat compatibility (E30, M30, CS7500). It then verifies if the indoor unit is a variable speed type or if it's a furnace requiring TXV. Based on these inputs, it determines if the application is approved and guides the selection of the appropriate EDA model, outdoor unit, and piping kit. It also specifies requirements for LZSV zoning systems and downflow installations.

Decision Flow:

1. Start
2. Zoning application? (YES/NO)
3. If YES, E30, M30 or CS7500 Thermostat? (YES/NO)
4. If NO to Zoning, LZSV Zoning System? (YES/NO)
5. If LZSV YES, order Humiditrol® Zoning Accessory (HZA) Kit.
6. If NO to Zoning, and NO to LZSV, Application Not Approved - DO NOT INSTALL.
7. If YES to Thermostat, select appropriate outdoor and indoor units based on compatibility lists. Note restrictions for variable-capacity outdoor units.
8. Select EDA model based on capacity and preferred/allowed match-up to indoor coil.
9. Select Piping Kit based on AC/HP type, capacity, and outdoor unit model.
10. Determine installation method (Upflow/Horizontal or Downflow).
11. Install System.

Performance

Supply Temperature vs. Outdoor Temperature

This graph shows that the indoor leaving dry bulb (DB) temperature is lower when the EDA unit is active compared to when it is inactive, across various outdoor temperatures (65°F to 82°F). The difference is approximately ± 3% for all unit matches.

Sensible to Total Ratio (S/T) vs. Outdoor Temperature

The graph indicates that the Sensible to Total Ratio (S/T) is higher when the EDA unit is active, meaning the system removes more sensible heat relative to total heat, across outdoor temperatures from 65°F to 82°F. The difference is approximately ± 3% for all unit matches.

Gallons of Water Removed per Hour/Ton vs. Outdoor Temperature

This graph demonstrates that the EDA unit significantly increases the amount of water removed per hour per ton of cooling capacity, especially at lower outdoor temperatures (65°F to 82°F). The EDA unit removes approximately 0.04 to 0.06 gallons more water per hour/ton compared to operation without the EDA. The data varies ± 3% for all unit matches.

Revisions