R32 Rooftop Heat Pumps for the U.S. Southwest

What HVAC Buyers Should Consider in Texas, Arizona, Nevada & New Mexico

Rooftop packaged HVAC units remain an important heating and cooling solution across the southwestern United States, particularly for low-rise buildings, replacement projects and applications where an all-in-one outdoor HVAC system is preferred.

But selecting a rooftop heat pump for the Southwest is not simply a matter of choosing the same tonnage as the existing unit.

Long cooling seasons, high outdoor temperatures, dry or mixed-dry climates, changing daytime loads, existing roof curbs, duct conditions and local electrical requirements can all influence equipment performance and replacement suitability.

For HVAC contractors, distributors and project buyers serving Texas, Arizona, Nevada and New Mexico, modern inverter rooftop heat pumps provide an opportunity to replace aging packaged equipment with systems designed around improved part-load performance, flexible airflow and current refrigerant requirements.

Why the U.S. Southwest Deserves a Different Rooftop HVAC Strategy

The Southwest contains several different climate conditions, so one rooftop HVAC strategy should not automatically be applied to every project.

Phoenix represents an extremely hot-dry cooling environment, while western Texas and southern New Mexico also experience strong summer cooling demand. Higher-elevation areas of New Mexico have greater winter heating requirements, while large parts of Texas can experience significantly different humidity conditions from west to east.

This makes equipment selection a balance between peak capacity and how efficiently the system operates during the many hours when the building is below peak load.

Market	Typical HVAC Consideration	Rooftop Heat Pump Priority
Texas	Long cooling seasons with climate conditions ranging from hot-dry western areas to more humid central and eastern markets	Cooling efficiency, humidity performance where required, retrofit compatibility and flexible airflow
Arizona	Very high summer temperatures and extended daytime cooling operation	High-temperature cooling performance, part-load efficiency, airflow and reliable outdoor operation
Nevada	Hot-dry conditions, strong daytime cooling loads and extended cooling seasons in southern Nevada	Inverter operation, energy efficiency, service access and effective load matching
New Mexico	Hot-dry and mixed-dry regions with larger temperature variation and greater heating requirements in some areas	Balanced cooling and heat-pump heating performance with appropriate project sizing

Conventional Packaged Units Still Work — But Buyer Priorities Are Changing

Traditional fixed-capacity rooftop packaged units remain practical for many buildings. Contractors understand them, replacement procedures are familiar and the initial equipment cost may be attractive.

The change is that more buyers now evaluate the complete operating life of the equipment rather than only the purchase price.

In the Southwest, rooftop HVAC equipment may operate for long periods during warm weather, but the building load is rarely at its maximum continuously.

Morning conditions, afternoon solar gain, occupancy, internal equipment loads and nighttime temperatures can all change the actual cooling demand.

Inverter Rooftop Heat Pumps and Part-Load Operation

This is where inverter rooftop heat pumps can offer an important difference.

Instead of relying only on repeated full-output compressor starts and stops, a variable-capacity compressor can adjust output according to changing building demand.

For Southwest applications, this can support:

• More stable indoor temperatures
• Reduced unnecessary compressor cycling
• Improved operation during partial-load conditions
• Better matching between building demand and HVAC output
• Quieter operation during reduced-load periods
• More consistent long-duration cooling operation

The benefit is not simply that the compressor is “inverter driven.” The real value comes from how capacity control, airflow and system controls work together during actual building operation.

Modern Inverter RTU vs. Conventional Packaged Unit

Comparison	Conventional Packaged Unit	Modern Inverter Rooftop Heat Pump
Compressor Control	Fixed or staged capacity depending on model	Variable-capacity operation
Part-Load Operation	More dependent on cycling or staged control	Can better follow changing building load
Temperature Stability	May experience wider cycling variation	Designed for smoother capacity adjustment
Indoor Airflow	Often fixed or limited-speed	ECM airflow adjustment available on modern platforms
Refrigerant Direction	Many older units use R410A or earlier refrigerants	New equipment can use lower-GWP refrigerants such as R32
Project Evaluation	Often selected as direct ton-for-ton replacement	Best results require load, airflow, duct and curb verification
Initial Cost	Can be lower	May be higher depending on efficiency and controls
Long-Term Focus	Simple replacement and basic operation	Efficiency, comfort, control and lifecycle performance

R32 Matters — But Refrigerant Is Only One Part of the Decision

The transition toward lower-GWP refrigerants is changing the U.S. residential and light-commercial HVAC market.

R32 falls below the current U.S. EPA 700-GWP limit applicable to new residential and light-commercial air-conditioning and heat-pump products.

For buyers, however, refrigerant choice should not be considered separately from the rest of the equipment.

A modern R32 rooftop heat pump should also be evaluated for:

• Certified cooling and heating performance
• Part-load efficiency
• Airflow capability
• External static pressure
• Installation orientation
• Service access
• Controls and thermostat compatibility
• Required refrigerant safety components
• Applicable A2L installation and service requirements

Why ENERGY STAR and AHRI Documentation Matter

High-efficiency claims are more useful to contractors and building owners when they can be supported by recognized certification and model-specific technical documentation.

ENERGY STAR establishes efficiency requirements for qualifying heat-pump equipment, while AHRI certified ratings allow contractors and buyers to verify applicable equipment performance and model combinations.

This documentation can be particularly important for:

• Contractor submittals
• Replacement project approval
• Energy-efficiency program review
• Customer comparison
• Equipment specification
• Project documentation

ENERGY STAR or AHRI certification does not automatically guarantee a rebate. Incentive eligibility can depend on the exact model, utility territory, ZIP code, customer type, installation date and current program requirements.

YUJU 2, 3 & 5 Ton R32 Inverter Rooftop Heat Pumps

YUJU provides a 2, 3 and 5 ton inverter rooftop packaged heat-pump series for residential and light-commercial applications in the U.S. market.

View 2, 3 & 5 Ton ENERGY STAR Rooftop Heat Pumps

Specification	2 Ton	3 Ton	5 Ton
Model	MYORU24NA22BCH19ES	MYORU36NA22BCH18ES	MYORU60NA22BCH17ES
Rated Cooling	24,000 BTU/h	33,000 BTU/h	56,000 BTU/h
Rated Heating	27,000 BTU/h	33,000 BTU/h	56,000 BTU/h
Refrigerant	R32	R32	R32
Power Supply	208–230V / 1Ph / 60Hz	208–230V / 1Ph / 60Hz	208–230V / 1Ph / 60Hz
Compressor	Inverter Rotary	Inverter Rotary	Inverter Rotary
Indoor Fan	ECM	ECM	ECM
Standard External Static	145 Pa	145 Pa	145 Pa

Capacity-class names are nominal categories. Final equipment selection should be based on calculated building load, design climate, airflow, duct resistance and applicable local requirements.

Airflow Matters as Much as Tonnage

One of the most common mistakes in rooftop replacement is assuming that matching nominal tonnage automatically means the new unit will work correctly with the existing duct system.

It may not.

The supply and return duct system must be able to deliver the required airflow at the available external static pressure.

For the YUJU rooftop heat-pump series, recommended system airflow is generally approximately 300–450 CFM per ton, with around 400 CFM per ton commonly used as a nominal starting point.

• 2 Ton: approximately 600–900 CFM
• 3 Ton: approximately 900–1,350 CFM
• 5 Ton: approximately 1,500–2,250 CFM

Final blower settings should consider duct resistance, installed accessories, cooling requirements and measured external static pressure.

What Contractors Should Check Before Replacing an Existing RTU

Replacement projects in the Southwest should begin with the existing building and HVAC conditions rather than the equipment catalog alone.

Check	Why It Matters
Calculated Heating & Cooling Load	Avoids automatically repeating an oversized or undersized existing unit
Existing Roof Curb	Determines whether an adapter or new curb is required
Supply / Return Direction	Confirms horizontal or downflow compatibility
Duct Size & External Static	Ensures required airflow can actually reach occupied spaces
Voltage / Phase / Frequency	Must match available electrical service
Thermostat & Controls	Ensures correct communication and system operation
Economizer Requirement	Can affect ventilation strategy and installation configuration
Refrigerant & Local Code Requirements	Important when replacing older R410A or legacy equipment with R32
Service Access	Future maintenance should be considered before final placement

Where 2–5 Ton Rooftop Heat Pumps Fit in the Southwest

Smaller rooftop packaged heat pumps are especially useful where the building requires an all-in-one outdoor HVAC system without the capacity or complexity of a larger commercial rooftop platform.

• Single-family homes using packaged rooftop HVAC
• Multi-family residential buildings
• Small offices
• Retail stores
• Workshops and service facilities
• Small production or light-industrial spaces
• Community and educational facilities
• Replacement of aging packaged rooftop units

Texas Is Not Arizona — and Arizona Is Not New Mexico

A strong rooftop HVAC specification should reflect the actual location of the project.

A unit selected for a hot-dry Phoenix application may face a different combination of cooling load, ventilation and humidity requirements than a project in Houston.

Likewise, a project in Albuquerque may require greater attention to winter heat-pump performance than a similar building in southern Arizona.

For Distributors and HVAC Contractors

YUJU can provide technical information for contractors and distributors evaluating rooftop replacement, retrofit or new-construction projects in Texas, Arizona, Nevada, New Mexico and neighboring markets.

Available project information can include:

• Model-specific technical submittals
• ENERGY STAR documentation
• AHRI certification information
• Electrical data
• Fan-performance information
• Airflow data
• Dimensions and installation information
• Roof-curb coordination information
• Optional electric-heater information
• OEM / private-label support
• Project-based equipment selection

What Information Should You Send for a Rooftop Replacement Quote?

Final Perspective

The move from an older conventional packaged unit to a modern R32 inverter rooftop heat pump should not be treated as a refrigerant change alone.

For Southwest projects, the more important question is whether the new rooftop system can combine appropriate capacity, efficient part-load operation, correct airflow, practical installation and verifiable performance for the actual building.

That is especially important in markets where rooftop HVAC equipment may operate for long hours under demanding summer conditions.