Overview

When a 7.5-ton HVAC system serving the kitchen at Full Goods Diner needed replacement, Shafer Mechanical faced an immediate challenge: the existing air handling unit had been installed before the restaurant space was built out, leaving no practical way to remove and replace it with another 7.5-ton unit.

Rather than recommending costly demolition to create access, Shafer Mechanical developed an alternative solution. Our team replaced the single 7.5-ton air handling unit with two 4-ton American Standard air handling units, twinned together and programmed to operate as a single system with one outdoor unit. 

 

 

During startup, our technician identified an additional equipment communication issue that could have affected long-term operation. Working directly with American Standard Technical Support, the team resolved the issue and verified system performance under the demanding conditions of an active commercial kitchen.

The Challenge

Replacing commercial HVAC equipment is rarely as simple as removing one unit and installing another, especially when the building has changed significantly since the original installation.

At Full Goods Diner, the existing 7.5-ton air handling unit had been installed before the restaurant space was built out. Once the surrounding construction was complete, there was no longer sufficient access to remove the existing equipment and bring in a new 7.5-ton AHU.

The restaurant still needed reliable cooling for its kitchen, where heat-producing equipment creates a significant HVAC load.

The challenge was to replace the failing system without unnecessary demolition while delivering the capacity and performance the space required.

The Solution: Two Air Handlers Working as One

Instead of trying to force another 7.5-ton air handler through a space that could not accommodate it, Shafer Mechanical developed a different approach.

The existing equipment was dismantled and removed in pieces. In its place, our team installed two 4-ton American Standard air handling units that could fit through the available access.

The two indoor units were then twinned, wired, and programmed to operate together as a single system connected to one outdoor unit.

This configuration allowed Shafer Mechanical to overcome the physical limitations of the space while providing the cooling capacity necessary for the restaurant kitchen.

Our technicians completed the refrigerant piping, electrical connections, thermostats, controls, and other components necessary to bring the new system online.

Catching an Issue During Startup

Once installation was complete, startup and commissioning uncovered another challenge.

During his evaluation, Shafer Mechanical technicians identified a mismatch involving the communication boards between the new indoor and outdoor equipment.

Rather than simply getting the equipment to run and leaving a potential issue unresolved, the technician contacted American Standard Technical Support.

Working directly with the manufacturer, he made the necessary wiring and control adjustments, tested the system, and confirmed that the final configuration was acceptable.

The system then powered on and began cooling properly.

Testing Under Real Kitchen Conditions

For Full Goods Diner, reliable HVAC performance matters most when the kitchen is operating and placing significant demand on the system.

Our technician completed a cooling log and evaluated system operation while it was under a heavy kitchen load. At the time of commissioning, the system was operating properly and delivering cooling as intended.

A follow-up evaluation was also recommended to confirm continued performance under normal operating conditions.

This commissioning process gave our team an opportunity to verify more than whether the equipment simply turned on. It helped ensure the custom configuration was performing properly under the conditions it would experience every day.

The Results

Shafer Mechanical successfully replaced a failing commercial kitchen HVAC system despite significant equipment-access limitations.

Project outcomes included:

• Replaced the inaccessible 7.5-ton air handling unit without requiring major demolition
• Installed two 4-ton American Standard AHUs twinned to operate as a single system
• Connected both indoor units to a single outdoor unit
• Completed new refrigerant, electrical, thermostat, and control connections
• Identified and resolved an equipment communication issue during startup
• Worked directly with American Standard Technical Support to verify the solution
• Confirmed cooling performance under heavy commercial kitchen load

The result was a practical replacement solution designed around the realities of the existing building rather than forcing the building to accommodate a conventional replacement.

Finding the Right Solution for the Building

One of the most important parts of commercial HVAC replacement is understanding that the original equipment configuration may no longer be practical years later.

Renovations, tenant build-outs, structural limitations, and access restrictions can all complicate equipment replacement.

At Full Goods Diner, replacing the existing system required our team to look beyond a standard like-for-like replacement. By using two smaller air handlers and configuring them to operate together, Shafer Mechanical was able to work within the existing space while restoring the cooling capacity the restaurant needed.

You’re Safer With Shafer

For restaurant operators, an HVAC problem in the kitchen can quickly become an operational problem.

Shafer Mechanical approaches commercial HVAC replacements with careful planning, technical expertise, and thorough commissioning. When an unexpected issue arises, our job is not to settle for “good enough.” It is to identify the problem, find the right solution, and verify that the system is operating as intended before calling the job complete.

Facing a commercial HVAC replacement complicated by equipment access or building constraints? Shafer Mechanical can help develop a solution around your facility and your operational needs.