Meeting Healthcare Challenges Through Prefabricated Modular Solutions and Engineering

By Jill Imig, PE, EDAC and Jeff Harris, PE, LEED AP

As the COVID-19 crisis puts pressure on healthcare facilities to meet patient surges, prefabricated modular solutions are gaining ground as viable alternatives to brick-and-mortar structures. As such, the STAAT ModTM (Strategic, Temporary, Acuity-Adaptable Treatment) is a quick-ship solution for healthcare ICU surge capacity, which HGA and The Boldt Company, in partnership with Tweet/Garot Mechanical, Faith Technologies and IMEG, collaborated to bring to market in response to the pandemic.

While there are many options that healthcare organizations will explore and deploy—from renovating clinical spaces, to renovating non-clinical spaces like hotels and conventions centers, to bringing temporary tents and structures on-site to house patients—the STAAT Mod offers a higher acuity level solution focused on patient and staff safety, where the need is to heal patients versus housing patients for observation.

In order to meet the demand for ICU style patient rooms to treat COVID-19 patients, the solution is built of standard equipment and parts, modular to allow for shipping, and prefabricated. The challenge for the design and construction team was to focus on the critical aspects of an ICU nursing unit, while making the engineering system modular and prefabricated and composed of equipment that is standardized and available “off the shelf.”  The unit also needed to be built within dimensions able to be shipped by truck, 12.5’ x 40’ x 10’.   

The fabrication line can produce two modules per day, with 16 Airborne Infection Isolation Room’s (AIIR) fully installed, including site prep, in two weeks, and ready for owner occupancy and activation. The units are fully finished in the fabrication shop prior to being shipped, with mod connection and minor corridor finishing completed in the field. The first units were recently shipped to a site for a healthcare provider on the East Coast, where the foundation had been prepared and the site utilities installed. Once the modules arrived, they were lifted into place and connected in less than two hours.

Key Attributes

While the STAAT Mod is prefabricated, the solution promotes better clinical outcomes and protects staff and patients when isolation and/or higher level of clinical quality is needed. Key attributes include:

• Airborne Infection Isolation Room (AIIR) solution that meets CDC recommends for aerosol generating procedures.
• Highly engineered for hospital-quality environments designed from a “kit of parts” to be manufactured and assembled quickly.
• Expert tested by lean process engineers, critical care nurse trained in COVID-19 protocols, and hospital environment specialist in infection control using a virtual reality platform.
• Ability to be configured for multiple applications, from rooms inside other structures (assembly hall, convention center), attached to hospital infrastructure, or a self-sufficient, free-standing deployed hospital that can be placed anywhere.

Room Features

The features of the Airborne Infection Isolation Room (AIIR) are driven by evidence-based design research that have been proven to increase staff and patient safety and improve clinical outcomes. AIIR features include:

• Donning station in alcove allows for hand washing prior to donning PPE equipment and entering room.
• Doffing zone allows removal and disposal of contaminated PPE, with hand wash prior to entering clean corridor.
• Fixed medical gasses provide access to ventilators, cardiac and vital monitoring, and respiratory treatment at the headwall.
• The 15-foot wide room orientation provides adequate space for safe bed transfers and portable chest x-ray, and room for a recliner to improve healing
• Mobile carts with medical supplies for direct patient care and patient charting.
• Viewing window into patient room from the corridor.
• Exterior windows to reduce staff stress, improve staff well-being, and increase job satisfaction.

Engineering Solutions

Due to the contagious nature of the Coronavirus and other potential communicative diseases, the engineering systems play a crucial role in maintaining patient and staff safety.

HVAC Systems

The key attribute of the STAAT Mod HVAC system is that it provides negatively pressurized patient rooms with high air changes rates of HEPA filtered air, providing an Airborne Infectious Isolation room environment to promote patient recovery and staff safely. The HVAC system accomplishes this by exhausting approximately 80 cfm per room, pulling air into the patient room (or the ward), in order to protect staff in adjacent work areas outside the room. The HVAC system incorporates an airflow design featuring HEPA filtration of the recirculated air, MERV 14 filtration of the supply air, and air distribution designed so that supply air passes past staff toward the patient, where it is exhausted through a low wall grille, capturing as many particles as possible.

Plumbing Systems

Medical gas systems consisting of medical air, medical vacuum, and oxygen are provided, with outlets incorporated into the patient room headwall and the systems fully piped for distribution. Each tier can be connected to a site’s medical gas infrastructure, or a separate C-Can, containing a medical air compressor, medical vacuum pump, and a manifolded oxygen tank system can be provided.

Similarly, each unit is equipped with proper handwashing facilities, and with the plumbing fixtures needed to provide for patient and staff care. Domestic cold water is piped between units, and electric water heaters are provided. The plumbing fixtures all drain via a gravity sanitary waste system, which can be connected to the site utilities or a holding tank for periodic removal. The sanitary waste system runs under the floor through the structural supports and is heat traced as needed.

Electrical Systems

The power distribution system for the STAAT Mod consists of a normal (utility) source and an essential systems (generator) source and is based upon a 480V distribution. The power is separated into normal, life safety, critical, and equipment branch sources compliant with NFPA 70 requirements. The primary distribution is in a stand-alone primary power module and the generator is provided on a separate skid with additional fuel storage. The primary distribution scheme is scalable to a three-tier configuration by adjusting breaker settings, increasing primary cabling, addressing the size of the generator, and adding additional distribution equipment to sustain each tier. Each tier has distribution equipment to sustain the power, lighting, systems, and mechanical requirements for that tier. Receptacles are designed to meet FGI guidelines and the lighting design meets the intent of IES illumination requirements. Each unit identifies circuits serving the unit to assist in the modular construction.

Each tier has a dedicated IT room furnished with two racks. The low voltage systems meet the intent of the FGI guidelines and are designed with a complete fire alarm system. Each module is technology ready with boxes, raceways, and a pathway to designated location above room door. Cabling and terminations will be completed at the device and in the IT closet. The nurse call system will meet the intent of the FGI guidelines and will create a complete patient communications system. Monitoring of engineering systems is provided to the IT room for integration into Owner furnished equipment.

Looking Forward

The demand and the peak of infection may vary by region, social distancing protocols, and urban or rural geography. Wherever clients are in that curve, it is clear the current situation is financially untenable. Further, much is being reported now about the dangers for patients who need care but are unsure if it is safe to go to the hospital, often presenting much later than they should to achieve the best possible outcomes. While telehealth services and home visits can supplement some hospital visits, other in-person appointments cannot be replaced.

The modules have a 10-year useful life, originally designed to dimensions that could ship without delays caused by oversized loads so they could be on site to meet crisis demand. The design has since evolved to

support a longer-term strategy solution that enables hospitals to separate patient populations without sacrifice to the levels of quality, safety, efficiency, or dignity of patients.

While these are temporary hospitals, this is not disposable construction. They are designed to be portable (move to where the need is greater) and stand-alone so they can be used in other situations and reconfigured to meet needs beyond this pandemic: clinical exam rooms, medical school simulation classrooms, housing and shelters, administrative space, swing space for future renovations—the opportunities are many.

Jill Imig, PE, EDAC, is Mechanical Engineering Department Leader at HGA in Milwaukee, where she specializes in plumbing systems.
Jeff Harris, PE, LEED AP,  is National Director of Engineering at HGA.