Large-Capacity Rooftop HVAC Units | 20–60+ Ton Custom RTU - YUJU

Large Rooftop HVAC Requires More Than Tonnage Selection

As rooftop HVAC capacity increases, equipment selection becomes increasingly project-specific. A 20 Ton, 30 Ton, 40 Ton or 50 Ton rooftop unit should not be evaluated by nominal cooling capacity alone.

The complete installation may need to consider:

• Required cooling and heating capacity
• Supply airflow
• External static pressure
• Downflow or horizontal air discharge
• Supply and return opening dimensions
• Fresh-air intake and ventilation
• Existing rooftop curb dimensions
• Electrical supply
• Refrigerant platform
• Climate and high-ambient operation
• Coastal corrosion protection
• Controls and building-management integration
• Unit footprint and weight
• Transportation, crane and installation limitations

20 Ton to 60+ Ton Project-Based RTU Configurations

YUJU can support large commercial rooftop HVAC projects across a broad capacity range. Final available configurations depend on project requirements and the selected equipment platform.

Capacity Range	Typical Applications
20–25 Ton	Commercial buildings, retail, restaurants and smaller institutional applications
30–40 Ton	Medical facilities, large retail spaces, schools, offices and commercial buildings
40–60+ Ton	Large commercial, institutional and project-specific rooftop HVAC applications

Final capacity should be selected according to building load, outdoor design conditions, ventilation load, airflow, operating schedule and actual project requirements.

Large Rooftop Unit Replacement & Retrofit

One of the most important applications for large-capacity rooftop equipment is the replacement of aging existing RTUs.

Commercial buildings may operate rooftop units for many years. When equipment reaches the replacement stage, the new unit needs to be coordinated with the existing building rather than selected only according to the old nominal tonnage.

For replacement projects, YUJU can review:

• Existing manufacturer and model number
• Existing cooling and heating capacity
• Supply airflow
• External static pressure
• Voltage, phase and frequency
• Downflow or horizontal configuration
• Supply and return opening sizes
• Existing rooftop curb dimensions
• Fresh-air or economizer configuration
• Controls and thermostat requirements
• Overall equipment dimensions and weight

Existing Roof Curb & Duct Compatibility

Replacing a large rooftop unit does not always require rebuilding the complete roof opening and duct system.

If the existing curb and ductwork are suitable, a replacement rooftop unit may be coordinated with the existing installation through compatible openings, transitions or a properly engineered curb adapter.

The engineering review should consider:

• Existing curb dimensions
• Supply and return openings
• Equipment footprint
• Unit weight and roof loading
• Airflow direction
• Existing duct dimensions
• Required airflow
• External static pressure

Downflow Rooftop HVAC Systems

Downflow configuration is widely used for roof-mounted commercial HVAC systems where supply and return air pass directly through the bottom of the unit into the building duct system.

For replacement projects, the location and dimensions of the existing supply and return openings should be confirmed before finalizing the new rooftop unit.

Depending on the selected platform, horizontal-discharge configurations may also be available for applications requiring side duct connections.

Fresh-Air Intake & Ventilation

Large commercial rooftop units can be configured with outdoor-air intake to meet building ventilation requirements.

Depending on the equipment and project, available options may include:

• Fresh-air intake hood
• Adjustable outdoor-air intake
• Motorized outdoor-air damper
• Economizer options
• Return-air and outdoor-air mixing

Fresh-air quantity introduces additional sensible and latent load, so ventilation requirements should be included when final capacity is selected.

Airflow & External Static Pressure

For large rooftop HVAC systems, fan performance can be just as important as refrigeration capacity.

A 40 Ton rooftop unit may have sufficient nominal cooling capacity, but it must also deliver the required airflow against the resistance of the actual commercial duct network.

Pressure loss can result from:

• Supply and return ductwork
• Filters
• Elbows and transitions
• Dampers
• Grilles and diffusers
• Fresh-air components
• Air-treatment accessories

YUJU AIRFORM™ Air Distribution Engineering

For project-based rooftop HVAC applications, YUJU can combine equipment selection with airflow and duct-system evaluation.

The engineering process can consider:

• Building cooling and heating load
• Required supply airflow
• Fresh-air load
• Main and branch duct sizing
• Duct velocity
• Supply and return pressure loss
• External static pressure
• Diffuser and grille requirements

R32 & Future Lower-GWP Refrigerant Platforms

YUJU supports project configurations using lower-GWP refrigerant platforms such as R32, depending on equipment size, application and target-market requirements.

At the same time, YUJU continues to evaluate future large-capacity rooftop HVAC platforms using other lower-GWP refrigerants, including R454B, as equipment technology, certification and market requirements continue to evolve.

Available refrigerant configurations should therefore be confirmed according to the required capacity and individual project.

Florida & Coastal Rooftop HVAC Applications

Commercial rooftop equipment installed in Florida and other coastal environments can face high outdoor temperatures, humidity, salt exposure, strong solar radiation and long annual cooling seasons.

Depending on the project, YUJU can evaluate options such as:

• Coil corrosion protection
• Enhanced cabinet protection
• Stainless-steel components where required
• High-ambient operating requirements
• Fresh-air and humidity load
• Roof installation coordination
• Wind-load and local installation considerations

40 Ton Rooftop HVAC Replacement Project in Florida

YUJU has supported a 40 Ton commercial rooftop HVAC replacement project for a medical facility in Florida, USA.

The project required a custom large-capacity rooftop solution based on actual replacement conditions, including:

• 40 Ton nominal capacity
• R32 refrigerant platform
• Downflow air distribution
• Fresh-air intake
• Commercial three-phase electrical supply
• Existing rooftop HVAC replacement coordination
• Coastal-environment considerations
• International equipment supply and logistics

View the 40 Ton Florida Rooftop HVAC Replacement Project →

High-Efficiency RTU Replacement & Energy Incentives

Replacing aging rooftop equipment can also be an opportunity to improve building energy performance and reduce long-term operating costs.

For eligible light commercial HVAC equipment within the applicable capacity range, ENERGY STAR certification may be relevant when the equipment meets the required performance criteria.

Large commercial rooftop units above the ENERGY STAR Light Commercial HVAC capacity range should be evaluated differently. These systems may still qualify for utility, state, regional or other commercial energy-efficiency incentives depending on project location, equipment efficiency and program requirements.

Check Local Incentives Before Equipment Purchase

Commercial HVAC incentives vary significantly by location. Depending on the program, eligibility may consider:

• Project ZIP Code
• Electric or gas utility provider
• Existing equipment
• Replacement equipment capacity
• EER, IEER or other applicable efficiency ratings
• Compressor staging or variable-capacity operation
• Supply-fan efficiency and control
• Building type
• Installation date

Some incentive programs may require pre-approval or minimum efficiency performance before equipment is purchased or installed. Building owners and contractors should therefore verify applicable local requirements early in the replacement process.

Why Part-Load Efficiency Matters

Large commercial rooftop systems spend much of their operating time below peak cooling load.

For this reason, ratings such as IEER can be important when comparing commercial HVAC energy performance.

Variable-capacity compressors, efficient fan systems, improved economizer controls and better part-load operation can contribute to lower annual energy consumption.

Replacing Older RTUs Can Improve More Than Efficiency

An older commercial rooftop unit may have lower-efficiency compressors, constant-speed fans, outdated fresh-air controls or aging refrigeration components.

A replacement project can be an opportunity to evaluate:

• Higher full-load and part-load efficiency
• Variable-capacity compressor technology
• Variable-speed or EC fan systems
• Improved fresh-air control
• Economizer functions
• Modern thermostat and building controls
• Lower-GWP refrigerants
• Improved corrosion protection

Custom Large-Capacity RTU & OEM Support

Large-capacity rooftop equipment often requires more project-specific configuration than standard small commercial systems.

Depending on the project and available production platform, YUJU can support:

• Project-specific capacity
• R32 and other suitable refrigerant platforms
• Voltage and frequency configuration
• Downflow or horizontal airflow
• Fresh-air intake
• High external static pressure
• Corrosion-protection options
• Control-system requirements
• Private-label branding
• Technical documentation
• Project-specific cabinet requirements

What Information Should You Send YUJU?

For large rooftop HVAC inquiries, complete project information can significantly improve equipment selection and quotation accuracy.

• Required capacity or existing RTU model
• Project location / ZIP Code
• Voltage / Phase / Frequency
• Required refrigerant
• Downflow or horizontal discharge
• Required supply airflow
• External static pressure
• Fresh-air requirement
• Supply and return opening dimensions
• Existing curb dimensions for replacement projects
• Maximum allowable equipment dimensions
• Corrosion-protection requirement
• Efficiency or local incentive requirements if known
• Required quantity