Project Background

Commercial medical facilities require dependable HVAC operation, particularly in Florida where high outdoor temperatures, humidity and long annual cooling seasons place significant demand on rooftop equipment.

The existing rooftop HVAC system had reached the replacement stage, creating the need for a new large-capacity RTU that could be coordinated with the building's existing mechanical and electrical conditions.

Instead of treating the project as a simple 40 Ton equipment purchase, YUJU reviewed the replacement requirements as a complete rooftop HVAC application.

Why a 40 Ton RTU Replacement Requires Project-Specific Engineering

Large commercial rooftop units are very different from standard small-capacity packaged equipment.

For a 40 Ton replacement project, nominal cooling capacity is only one part of the selection process. The replacement equipment also needs to coordinate with:

• Required supply airflow
• External static pressure
• Existing supply and return ductwork
• Existing rooftop curb and roof opening
• Downflow or horizontal airflow direction
• Fresh-air requirements
• Electrical supply
• Existing control system
• Equipment dimensions and weight
• Roof installation and lifting conditions
• Local climate and corrosion exposure

Key Project Requirements

Item	Project Requirement
Equipment Type	Large-Capacity Commercial Packaged Rooftop Unit
Nominal Capacity	40 Ton / Approx. 480,000 Btu/h
Refrigerant	R32
Airflow Arrangement	Downflow Supply & Return
Fresh Air	Outdoor-Air Intake Hood
Electrical	460V / 3 Phase / 60Hz
Application	Medical / Healthcare Facility
Environment	Florida Hot-Humid / Coastal Application

R32 Refrigerant Platform

The 40 Ton rooftop unit for this project uses an R32 refrigerant platform.

R32 provides a lower-GWP alternative to traditional higher-GWP refrigerants and is used in a growing range of modern HVAC equipment.

Refrigerant selection for commercial rooftop equipment should always be confirmed according to equipment design, required capacity, destination-market requirements and applicable regulations.

Downflow Supply & Return Configuration

The Florida project uses a downflow rooftop configuration.

In a downflow RTU, conditioned supply air and return air pass through the bottom of the equipment into the building's roof-mounted duct system.

For replacement applications, the existing supply and return openings should be compared with the new equipment before final production.

Existing Roof Curb & Duct Interface

One of the most important considerations in rooftop replacement projects is compatibility with the existing roof curb and duct openings.

A new RTU does not necessarily need exactly the same external cabinet dimensions as the original equipment, but the connection between the new unit, roof opening and existing ductwork must be properly engineered.

Depending on the replacement conditions, the solution may involve:

• Compatible supply and return openings
• Duct transition sections
• Custom curb adapter
• New roof curb where required

For future replacement projects, customers can provide existing unit drawings, curb dimensions and installation photographs for preliminary compatibility review.

Airflow & External Static Pressure

A large-capacity rooftop unit must provide both sufficient refrigeration capacity and sufficient fan performance.

Even if a rooftop unit provides 40 Tons of nominal cooling, the HVAC system will not perform correctly if the supply fan cannot deliver the required airflow against the resistance of the connected duct system.

Pressure loss can come from:

• Supply ductwork
• Return ductwork
• Filters
• Elbows and transitions
• Dampers
• Diffusers and grilles
• Fresh-air components

YUJU AIRFORM™ Air Distribution Engineering

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

Engineering review can include:

• Building cooling-load review
• Required supply airflow
• Fresh-air load
• Main and branch duct sizing
• Air velocity
• Pressure-loss evaluation
• External static pressure
• Supply and return-air coordination

This allows the RTU fan and cooling capacity to be selected around the actual building requirements rather than nominal tonnage alone.

Fresh-Air Ventilation

The project includes an outdoor-air intake hood to introduce ventilation air into the rooftop HVAC system.

Fresh-air requirements are particularly important for commercial and healthcare applications where occupancy and ventilation requirements can significantly affect total HVAC load.

Outdoor air adds both sensible and latent load, so fresh-air quantity should be included during final equipment selection.

Florida Hot-Humid & Coastal Environment

Florida rooftop HVAC equipment can operate under demanding environmental conditions, including high temperature, high humidity, salt exposure, strong solar radiation and long annual cooling seasons.

For coastal applications, project-specific protection can be considered according to installation distance from the coast, environment and customer requirements.

Enhanced Coastal Protection Options

• Enhanced cabinet corrosion protection
• Epoxy or other protective coil coating
• 316 stainless-steel fasteners where required
• Corrosion-resistant structural components
• Project-specific outdoor protection

Standard commercial configurations can also be provided for applications where enhanced coastal protection is not required.

Market-Specific Certification & Compliance Support

Commercial HVAC equipment cannot be treated as having one universal certification for every country or project.

Required certification, documentation and compliance pathways can vary according to:

• Destination country
• State or local jurisdiction
• Equipment capacity
• Refrigerant
• Electrical configuration
• Building type
• Project specification

Market	Typical Compliance Considerations
United States	Applicable AHRI performance certification, ETL / UL safety certification, DOE efficiency requirements, refrigerant requirements and local mechanical / electrical codes, depending on the selected equipment.
Florida	In addition to applicable U.S. requirements, project teams may need to consider Florida-specific building, roof installation, wind-load and local permitting requirements.
High-Velocity Hurricane Zones	Miami-Dade / Broward-area projects may require additional review of wind resistance, anchoring, structural installation and applicable local approvals.
European Market	CE conformity, applicable Ecodesign / ErP requirements and relevant European safety and energy-performance standards.
Other International Markets	Certification and documentation are reviewed according to the destination country's regulations, import requirements and project specifications.

Energy Efficiency & Replacement Incentive Considerations

Replacing older rooftop HVAC equipment can provide an opportunity to improve full-load and part-load energy performance.

Large commercial RTUs may be evaluated using efficiency metrics such as EER and IEER, depending on equipment type and capacity.

A 40 Ton rooftop unit is approximately 480,000 Btu/h and falls outside the current ENERGY STAR Light Commercial HVAC certification capacity range.

However, large commercial HVAC replacement projects may still qualify for utility, state, regional or other energy-efficiency incentive programs depending on project location, equipment efficiency and individual program requirements.

Building owners and contractors should verify local incentive requirements before ordering equipment because some programs require pre-approval or specific performance documentation.

20–60+ Ton Large-Capacity Rooftop HVAC Capability

The Florida 40 Ton project also demonstrates YUJU's ability to support large-capacity rooftop HVAC applications beyond standard small commercial packaged equipment.

Depending on project requirements and available equipment platforms, YUJU can support large-capacity RTU applications including:

• 20 Ton rooftop units
• 25 Ton rooftop units
• 30 Ton rooftop units
• 40 Ton rooftop units
• 50 Ton rooftop units
• 60+ Ton project-specific rooftop systems

These applications are normally evaluated as project-based equipment rather than standard inventory products.

Project-Specific RTU Customization

Large rooftop equipment frequently requires project-specific configuration.

Depending on engineering feasibility, equipment platform and order requirements, YUJU can coordinate options including:

• Cooling-capacity configuration
• Electrical voltage and frequency
• Refrigerant platform
• Downflow or horizontal discharge
• High external static pressure
• Fresh-air intake
• Corrosion protection
• Control interfaces
• Cabinet and connection requirements
• Private-label branding
• Technical documentation

Engineering, Manufacturing Coordination & International Delivery

YUJU acts as an HVAC solution and project-integration partner, coordinating equipment engineering, manufacturing resources, quality verification and international project requirements.

The project process can include:

• Technical requirement evaluation
• Equipment configuration
• Engineering confirmation
• Manufacturing coordination
• Factory quality inspection
• Performance verification
• Export packaging
• Shipping documentation
• International logistics coordination
• After-sales technical support

Planning Future RTU Replacement Projects

Large medical, commercial and institutional facilities often operate multiple rooftop HVAC units with different capacities and installation conditions.

When additional equipment reaches its replacement cycle, facility owners and contractors can provide an existing equipment schedule for preliminary replacement planning.

YUJU can help organize a replacement matrix based on:

• Existing RTU model
• Capacity
• Age and operating condition
• Supply airflow
• External static pressure
• Roof curb dimensions
• Electrical supply
• Refrigerant platform
• Replacement priority

Frequently Asked Questions

Can a new 40 Ton RTU replace an existing rooftop unit?

Yes. The replacement should be evaluated according to capacity, airflow, ESP, existing curb, duct openings, electrical supply and installation conditions.

Can the existing roof curb be reused?

Potentially yes. If the new equipment does not directly match the existing curb, a properly engineered curb adapter or transition may be considered.

Can existing ductwork be reused?

Yes, if the duct network is in acceptable condition and can provide the required airflow at an acceptable external static pressure.

Can YUJU provide RTUs larger than 40 Tons?

YUJU can support project-based large-capacity rooftop HVAC requirements, including 20 Ton, 30 Ton, 40 Ton, 50 Ton and larger configurations, subject to project specifications and equipment-platform availability.

Can large rooftop units use R454B in the future?

Large-capacity lower-GWP RTU platforms continue to develop. YUJU can evaluate R454B and other refrigerant options according to available equipment, certification and individual project requirements.

What certification is required for a U.S. rooftop HVAC project?

Requirements depend on the equipment, state and project. Applicable AHRI performance certification, ETL / UL safety certification, efficiency requirements and local mechanical, electrical and building regulations should be reviewed before final equipment confirmation.