Dual A2L Refrigerant Systems - Aspen Manufacturing

What are Dual Refrigerant Products?

Dual Refrigerant systems are Aspen coils and air handlers that can be field-configured and installed with A2L refrigerant systems, R-454b or R32.*

Click arrow to read more

Dual Safety Listed for R32 and R454B. Compliant with UL 60335-2-40.
- Dual A2L Refrigerant System coils and air handlers are configured to either R32 or R454B in the field with approved Metering Device. Dual A2L Refrigerant Systems MAY NOT be installed with R410A systems per UL 60335-2-40.
- In accordance with UL 60335-2-40, Aspen Dual Refrigerant models are approved for sale as Dual A2L Refrigerant Systems and may be field-configured for use with either R32 or R454B using an approved metering device.
- Dual Refrigerant evaporator coils and air handlers are not approved for use with R410A systems and must not be installed in R410A applications.
- UL 60335-2-40 explicitly prohibits evaporator coils and air handlers from being sold, rated, or installed for use with both A1 (R410A) and A2L (R32 and R454B) refrigerants.
- NOTE: Mobile Home air handlers are NOT Dual Refrigerant products. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.
What is UL 60335-2-40?
- UL 60335-2-40 is a safety standard for household and similar electrical appliances. UL 60335-2-40 outlines various safety requirements, including protections against electric shock, fire hazards, and mechanical hazards. It also covers requirements for marking and instructions for use, and testing procedures to ensure compliance with the safety requirements.
  - Click here to view UL 60335-2-40 on the Intertek website.
- UL 60335-2-40 is one of several safety standards that manufacturers of electrical appliances must comply with in order to ensure the safety of their products for consumers. Compliance with these standards is typically indicated by a certification mark on the product, such as the ETL mark.
What are Dual Refrigerant Coils?
- UL 60335-2-20 COMPLIANT – Dual calibrated refrigerant detection sensor for use with both refrigerants, allowing for a universal Refrigerant Detection System (RDS) (with and without a relay).
- Factory or field-mounted metering device (Piston or TXV). Dual Refrigerant products offer options of factory installed R32 and 454B pistons; and R32 and 454B TXVs with 20% bleed.
- Field configurable – Dual Refrigerant products can be marked in the field for the A2L refrigerant used at the time of installation.
- Click here to view all of Aspen’s Dual Refrigerant Evaporator Coils.
What are Dual Refrigerant Handlers?
- UL 60335-2-20 COMPLIANT
- FACTORY OR FIELD-MOUNTED METERING DEVICE (Piston or TXV). Versa Pro products come standard with a R454B Piston.
- FACTORY INCLUDED OR FIELD-MOUNTED RDS OPTIONS – Dual calibrated refrigerant detection sensor for use with both refrigerants, allowing for a universal Refrigerant Detection System (RDS) (with and without a relay).
- FIELD CONFIGURABLE – Versa Pro products can be marked in the field for the A2L refrigerant used at the time of installation.
- Click here to view all of Aspen’s Versa Pro Air Handlers.
- NOTE: Mobile Home air handlers are NOT Versa Pro. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.
How do I order a Dual Refrigerant product?
1. Talk to your local Aspen Sales representative for ordering details.
  - Dual A2L Refrigerant Detection System (RDS) Kit Part Numbers:
    - A2LZS – A2L RDS KIT, R454B and R32, Standard
    - A2LZR – A2L RDS KIT, R454B and R32, W/ Relay
2. Aspen RDS Kits manufactured prior to the release of Dual Refrigerant RDS Kits are NOT UL 60335-2-40 certified and CANNOT be configured from a R32 to an R454B, or R454B to a R32. The following Aspen RDS Kit models will be superseded by A2LZ(S/R):
  - A2L4S(A/B)
  - A2L3S(A/B)
  - A2L4R(A/B)
  - A2L3R(A/B)
3. Dual Refrigerant Product Warranty: Field installed parts, including TXVs and Refrigerant Detection Systems (RDS), carry a 1-year warranty; factory installed parts carry the warranty of the product they are installed in.

*UL 60335-2-40 DOES NOT allow for Dual Refrigerant coils and air handlers to be sold/rated/installed with both A1 (R410A) and A2L (R32 & R454B) refrigerants.

NEW RDS Kits - Ideal use for Aspen Evaporator Coils and Air Handlers

Aspen provides universal RDS kits for R32 and R454B to provide optimal performance and avoid nuisance or false alarms that can occur in inferior products. The innovative RDS kits have unique features allowing flexibility in installation and application. The kits are compatible with all Aspen coils. Certified to meet the requirements of UL 60335-2-40, each kit provides for a complete installation of sensor and mitigation device required by the UL standard. Kits with relay have an optional functionality to control additional equipment or accessories.

With two kits in total (standard RDS kit, RDS kit with relay, a Aspen has a kit that works for every application. Aspen’s RDS kits connect through the 24-volt connection on the furnace with provided field wiring and shuts down the condenser and turns on the furnace blower to dilute the refrigerant concentration below the flammability limit when activated.

Dual A2L Refrigerant Detection System (RDS) Kit Options

Option S – Standard Mitigation Control Kit

Turns on indoor blower to dissipate refrigerant concentration and cuts power to outdoor unit to stop new refrigerant from entering the space. Kit includes all components needed for RDS installation.

Option R – Mitigation + Accessory Control Kit

Includes the same functionality as standard option plus ability to energize/de-energize up to four inputs for accessories such as electric heat, gas furnace, air cleaners, and zoning systems.

Dual A2L RDS Kit Features

Compatible with ALL Aspen Coils.
UL 60335-2-30 Certified.
System designed to last the useful life of the evaporator coil.
Kit includes all components needed for RDS installation.
Sensor wire length of eight (8) feet, and mitigation board power wire length three (3) feet.
Optional relay for controlling additional components.
Flexible installation location, ideal for installs on existing equipment.
Available options of factory-installed R32 and R454B pistons; and R32 and R454B TXVs with 20% Bleed.
Supersedes current Aspen RDS Kit Models, including the following:
- A2L4S(A/B)
- A2L3R(A/B)
- A2L4R(A/B)
- A2L3R(A/B)

Dual A2L RDS Kit Specifications

The refrigerant detection kit has been designed and tested to meet UL 60335-2-40 4th edition safety standard.
Refrigerant detection sensors have been designed, tested, an calibrated specifically for both R454B and R32. Sensors have a 15+ year lifetime with no calibration required.
Mitigation control boards are programmed with logic and timing to complete proper mitigation measures per the UL standard.

Aspen offers two mitigation options:

- Standard mitigation control (S) – turns on indoor blower to dissipate refrigerant concentration and cuts power to outdoor unit to stop new refrigerant from entering the space.
- Mitigation + accessory control (R) – includes the same functionality as standard option plus ability to energize/de-energize up to four inputs for accessories such as electric heat, gas furnace, air cleaners, and zoning systems.
The kit utilizes the thermostat 24-volt wiring of the system.
The kit is field mounted to give installation flexibility on replacements applications.
All components needed for installation, including labels, wiring diagrams, cable/wire harnesses, and instructions, are included in the kit.

Aspen Dual Refrigerant Product Warranty

Field installed parts, including TXVs and Refrigerant Detection Systems (RDS), carry a 1-year warranty; factory installed parts carry the warranty of the product they are installed in.

Aspen Dual Refrigerant Product Resources

Technical Documents

View Dual A2L Refrigerant System 1-Page Sale Sheet View Dual A2L Refrigerant Systems Spec Sheet View Metering Device Selection Matrix

View TXV Installation Guide View View Field-Mounting Instructions Try AHRI Ratings Quick Match Tool

Since 1975, Aspen Manufacturing has been committed to delivering quality, trust, and reliability in every product we create. From our factory floor to your home or business, our team of HVAC industry leaders ensures energy-efficient solutions built to the highest standards.

What are Dual Refrigerant Products?

Dual Refrigerant systems are Aspen coils and air handlers that can be field-configured and installed with A2L refrigerant systems, R-454b or R32.*

Dual Safety Listed for R32 and R454B. Compliant with UL 60335-2-40.

Dual A2L Refrigerant System coils and air handlers are configured to either R32 or R454B in the field with approved Metering Device. Dual A2L Refrigerant Systems MAY NOT be installed with R410A systems per UL 60335-2-40.

In accordance with UL 60335-2-40, Aspen Dual Refrigerant models are approved for sale as Dual A2L Refrigerant Systems and may be field-configured for use with either R32 or R454B using an approved metering device.

Dual Refrigerant evaporator coils and air handlers are not approved for use with R410A systems and must not be installed in R410A applications.

UL 60335-2-40 explicitly prohibits evaporator coils and air handlers from being sold, rated, or installed for use with both A1 (R410A) and A2L (R32 and R454B) refrigerants.

NOTE: Mobile Home air handlers are NOT Dual Refrigerant products. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.

What is UL 60335-2-40?

Click here to view UL 60335-2-40 on the Intertek website.

UL 60335-2-40 is one of several safety standards that manufacturers of electrical appliances must comply with in order to ensure the safety of their products for consumers. Compliance with these standards is typically indicated by a certification mark on the product, such as the ETL mark.

What are Dual Refrigerant Coils?

UL 60335-2-20 COMPLIANT – Dual calibrated refrigerant detection sensor for use with both refrigerants, allowing for a universal Refrigerant Detection System (RDS) (with and without a relay)​.

Factory or field-mounted metering device (Piston or TXV). Dual Refrigerant products offer options of factory installed R32 and 454B pistons; and R32 and 454B TXVs with 20% bleed.

Field configurable​ – Dual Refrigerant products can be marked in the field for the A2L refrigerant used at the time of installation.

Click here to view all of Aspen’s Dual Refrigerant Evaporator Coils.

What are Dual Refrigerant Handlers?

UL 60335-2-20 COMPLIANT

FACTORY OR FIELD-MOUNTED METERING DEVICE (Piston or TXV). Versa Pro products come standard with a R454B Piston.

FACTORY INCLUDED OR FIELD-MOUNTED RDS OPTIONS – Dual calibrated refrigerant detection sensor for use with both refrigerants, allowing for a universal Refrigerant Detection System (RDS) (with and without a relay)​.

FIELD CONFIGURABLE​ – Versa Pro products can be marked in the field for the A2L refrigerant used at the time of installation.

Click here to view all of Aspen’s Versa Pro Air Handlers.

NOTE: Mobile Home air handlers are NOT Versa Pro. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.

How do I order a Dual Refrigerant product?

Talk to your local Aspen Sales representative for ordering details.

Dual A2L Refrigerant Detection System (RDS) Kit Part Numbers:

A2LZS – A2L RDS KIT, R454B and R32, Standard

A2LZR – A2L RDS KIT, R454B and R32, W/ Relay

Aspen RDS Kits manufactured prior to the release of Dual Refrigerant RDS Kits are NOT UL 60335-2-40 certified and CANNOT be configured from a R32 to an R454B, or R454B to a R32. The following Aspen RDS Kit models will be superseded by A2LZ(S/R):

A2L4S(A/B)

A2L3S(A/B)

A2L4R(A/B)

A2L3R(A/B)

Dual Refrigerant Product Warranty: Field installed parts, including TXVs and Refrigerant Detection Systems (RDS), carry a 1-year warranty; factory installed parts carry the warranty of the product they are installed in.