As high-performance homebuilding continues to evolve, HVAC systems are becoming more adaptable, offering builders and contractors greater flexibility in how they deliver comfort, efficiency, and indoor air quality. Carrier’s Crossover platform is designed with that flexibility in mind, combining variable-speed technology with multiple system configurations and control options.
In EEBA’s webinar, Crossover Dehum and Controls, Connor Howard, Product Marketing Manager of Residential HVAC at Carrier, explored how the platform can be configured to meet different project requirements, with a particular focus on dehumidification, system controls, and zoning.
Understanding the Crossover Platform
While horizontal-discharge systems have traditionally been associated with ductless applications, Carrier’s Crossover platform offers whole-home solutions ranging from 1.5 to 5 tons. Its inverter-driven, variable-speed compressor allows the system to adjust its output based on actual operating conditions, supporting more consistent comfort and performance.
The outdoor unit can be paired with different indoor configurations, including a furnace, residential fan coil, or dedicated two-wire communicating fan coil. This gives builders and contractors options when selecting equipment for new construction or retrofit projects.
A key distinction of the platform is its support for two control approaches: traditional 24V connections and Carrier’s two-wire communicating system.
24V vs. Two-Wire Controls
The two control options offer different ways for the system's components to communicate and manage performance.
With traditional 24V controls, the system operates through familiar signals such as Y1 and Y2. This provides compatibility with conventional thermostats and indoor equipment, making installation more straightforward for contractors already working with traditional HVAC configurations.
The two-wire RS-485 communicating platform takes a more integrated approach. The outdoor unit, indoor unit, and thermostat continuously exchange information, including return air temperature, supply air temperature, coil temperature, and outdoor conditions. The system uses this information to adjust compressor output and indoor airflow together.
Howard recommends the communicating configuration when the project allows for it, as it provides more advanced control, full compressor modulation, enhanced dehumidification, and system error notifications directly through the thermostat. Homeowners can also access system information through Carrier’s Climate app.
However, flexibility remains a major advantage of the platform. Builders and contractors can use third-party thermostats, including familiar smart thermostat options, without sacrificing the system's rated capacity and performance.
Improving Dehumidification Performance
One of the webinar's central topics was how the Crossover platform manages humidity, particularly in climates where homeowners experience warm temperatures and high relative humidity.
Effective dehumidification requires more than simply running the air conditioner at full capacity. As Howard explained, moving air more slowly across the indoor coil allows more time for moisture to condense and drain away. This is why reducing both compressor output and fan speed can improve moisture removal.
With the two-wire communicating controls, the system offers enhanced dehumidification. The compressor and fan motor continuously adjust together, allowing the system to maintain a more controlled, low-and-slow operation.
The platform also includes a dedicated Dry Mode. This feature allows homeowners to prioritize moisture removal when the indoor temperature is comfortable but humidity remains too high. Dry Mode operates on a selectable 30-, 60-, or 90-minute timer, focusing on extracting moisture while adjusting system operation to help prevent unnecessary overcooling.
Traditional 24V controls also support dehumidification through a dedicated DH terminal and a corresponding configuration setting. While this setup does not offer the same enhanced dehumidification algorithm or dedicated Dry Mode, it adjusts fan speed and compressor operation in response to the dehumidification signal.
Howard noted that Carrier's testing showed similar overall moisture removal across the three configurations discussed. The primary difference is how each system operates to achieve that result.
Crossover Zoning and System Compatibility
The webinar also covered Carrier's Crossover zoning capabilities. The platform supports zoning through a compatible 24V zone controller, provided the controller includes the necessary A2L safety logic and configurable reversing valve settings.
This allows builders to create multiple independently controlled areas within a home. One important consideration is that 24V zoning requires a 24V thermostat configuration rather than the two-wire communicating thermostat.
For projects where homeowners prefer an existing thermostat or smart home setup, the platform's built-in 24V interface also provides a practical solution. This allows contractors to connect compatible third-party thermostats while maintaining communication between the outdoor and indoor equipment.
More Options for Builders and Homeowners
A major takeaway from the discussion was that high-performance HVAC systems do not have to require a one-size-fits-all approach to controls. Carrier's Crossover platform offers multiple equipment combinations and control configurations, allowing builders and contractors to select solutions based on project needs, installation preferences, and homeowner expectations.
Whether using traditional 24V controls or a fully communicating two-wire system, the flexibility of the platform creates more opportunities to deliver reliable comfort and dehumidification performance.
Learn more: https://www.carrier.com/us/en/residential/crossover-solutions/
Watch the Webinar: Explore the full Crossover Dehum and Controls webinar with Connor Howard of Carrier through the EEBA Learning Management System.