Have you ever wondered how healthcare facility HVAC systems are designed for a wide variety of services for their patients, guests, and healthcare workers?  The term “Healthcare facilities” is broad and can be divided into three building categories:

  1. Hospitals
  2. Outpatient Care
  3. Nursing Facilities

For the purposes of this blog, let’s consider hospital buildings.


There are over 3,000 hospital buildings and more than 3 million employees that work in those buildings in the U.S. alone, according to Census reports. Hospitals offer a variety of services that utilize complex energy intensive processes. Furthermore, hospitals are open 24 hours a day and the systems that keep them running are capable of continuous operation and must adapt quickly to variable loads.

HVAC design for hospitals goes beyond comfort applications and can even be therapeutic for patients.

In order to conceptualize how a hospital HVAC system is designed, it’s important to consider various criteria for each department. Hospitals offer a wide variety of services that can be broken down into 7 primary areas as described by ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers).

These primary areas include:

  1. Surgery and Critical Care
  2. Nursing
  3. Ancillary
  4. Administration
  5. Diagnostic & Treatment
  6. Sterilizing & Supply
  7. Service

For example, HVAC criteria for a surgical area will be much different from a diagnostic room or service area. Methods of heating, cooling, and mitigation of bacteria varies between departments. Hospital air distribution systems are designed to restrict air movement between departments and wards. Air movement may be further controlled by maintaining positive, negative, or neutral room pressurization. Room pressurization generally moves air from clean areas to dirty areas. Surgery suites will have higher pressurization than a diagnostic room that has higher pressurization than a restroom.

In order to achieve this, the HVAC air distribution system may have automatic modulating dampers to control pressurization between adjacent rooms. Pressure sensors take measurements and provide feedback to the building automation system to monitor room conditions and modulate dampers accordingly. Pressure control methods might also include the use of anterooms, exhaust systems, or dedicated equipment.


The HVAC systems that serve hospitals have many specific requirements outlined in FGI Facility Guidelines for Design and Construction of Hospitals and Outpatient Facilities and Guidelines for Design and Construction of Residential Health, Care, and Support Facilities, which incorporates ANSI/ASHRAE/ASHE Standard 170.

Building Information Modeling (BIM) is commonly used to design HVAC systems for new construction and renovation projects.

Allegheny Design Services utilizes Autodesk Revit MEP to create building information models, drawings, and schedules of building systems. This design approach also applies to healthcare and hospital systems. Hospital BIM designs might include a central physical plant upgrade where piping and ductwork may need reconfigured within existing building. New construction projects and additions may benefit from equipment assemblies to be set in a one piece skid by fabricating off site. There are countless design scenarios each with a unique practical solution.

ADS is committed to help provide practical solutions to address client needs.

The collaboration effort between MEP system designs and healthcare facility requirements is important for a successful construction project or facility upgrade. We look forward to discussing potential projects with your facility staff and discuss possibilities for building information modeling applications for your next healthcare facility construction project.

Please click here to see examples of our recent MEP healthcare projects.

Written by David Cotton, PE, LEED AP BD+C, Senior Mechanical Engineer

david-cottonDavid is a resident of Morgantown, W.Va. He graduated from the Leonard C. Nelson College of Engineering & Sciences at the West Virginia University Institute of Technology with a bachelor’s degree in Mechanical Engineering and later obtained professional engineering licensure in the State of West Virginia. He is an active member of ASHRAE West Virginia Chapter, NFPA AEBO Section and USGBC West Virginia Section. He has experience with design and construction administration of MEP building systems for commercial, educational and industrial building projects. Additional experience includes LEED project administration, building systems commissioning and Revit building information modeling (BIM).

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