
What are Versa Pro Products?
Versa Pro systems are Aspen coils and air handlers that can be field-configured and installed with A2L refrigerant systems, R-454b or R32.*

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Dual Safety Listed for R32 and R454B. Compliant with UL 60335-2-40.
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Versa Pro coils and air handlers to be sold as a Dual A2L Refrigerant System and configured to either R32 or R454B in the field with approved Metering Device. Versa Pro MAY NOT be installed with R410A systems per UL 60335-2-40.
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In accordance with UL 60335-2-40, Aspen Versa Pro 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.
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Versa Pro evaporator coils and air handlers are not approved for use with R410A systems and must not be installed in R410A applications.
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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.
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NOTE: Mobile Home air handlers are NOT Versa Pro. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.
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What is UL 60335-2-40?
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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.
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Click here to view UL 60335-2-40 on the Intertek website.
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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.
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What are Versa Pro Coils?
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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).
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Factory or field-mounted metering device (Piston or TXV). Versa Pro products come standard with a R454B Piston.
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Field configurable – Versa Pro products can be marked in the field for the A2L refrigerant used at the time of installation.
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Click here to view all of Aspen’s Versa Pro Evaporator Coils.
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What are Versa Pro Air Handlers?
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UL 60335-2-20 COMPLIANT
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FACTORY OR FIELD-MOUNTED METERING DEVICE (Piston or TXV). Versa Pro products come standard with a R454B Piston.
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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).
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FIELD CONFIGURABLE – Versa Pro products can be marked in the field for the A2L refrigerant used at the time of installation.
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Click here to view all of Aspen’s Versa Pro Air Handlers.
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NOTE: Mobile Home air handlers are NOT Versa Pro. The Mobile Home coil identifies the system refrigerant on AHRI and/or job site.
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How do I order a Versa Pro product?
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Talk to your local Aspen Sales representative for ordering details.
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Versa Pro A2L Refrigerant Detection System (RDS) Kit Part Numbers:
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A2LZS – A2L RDS KIT, R454B and R32, Standard
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A2LZR – A2L RDS KIT, R454B and R32, W/ Relay
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Aspen RDS Kits manufactured prior to the release of Versa Pro 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):
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A2L4S(A/B)
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A2L3S(A/B)
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A2L4R(A/B)
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A2L3R(A/B)
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Versa Pro 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.
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*UL 60335-2-40 DOES NOT allow for Versa Pro 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.
Versa Pro 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.
Versa Pro 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.
- Supersedes current Aspen RDS Kit Models, including the following:
- A2L4S(A/B)
- A2L3R(A/B)
- A2L4R(A/B)
- A2L3R(A/B)
Versa Pro 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:
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- 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.
Versa Pro 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.
Versa Pro Resources
Versa Pro Resources + Technical Documents
