Today’s health care organizations are faced with countless challenges during the design and construction phases of a new facility or expansion project. One of the most important in mission-critical functions is the selection of an HVAC system.

This decision, often shared among the board of directors, architects, engineers and contractors, is one that likely will be revisited throughout the life of the building as future upgrades are contemplated and undertaken.

The health care facility itself may be a center of modern medical technology—with state-of-the-art diagnostic and medical equipment, pharmaceutical and research laboratories, and information services technology—but if environmental control failures occur, all of the positives will go unnoticed.

Nine key considerations

What factors influence this important decision? Here are nine key considerations for selecting a hospital HVAC system for new construction or as an upgrade to an existing facility, campus or institution.

1 / The team. The first consideration is the composition of the formal selection team to develop, guide, conduct and carry out the search and selection process. It’s essential that the team consists of key individuals who represent a cross-section of responsibilities, interests and expertise from throughout the hospital.

The Department of Energy’s “Building Toolbox” (www.eere.energy.gov/buildings/info/toolboxdirectory.html) advises project leaders to: “Identify members of the entire design team before beginning the design process. All those who can influence the building design and how it is constructed should be represented on the design team, including architects, engineers, owners, occupants and specialists in areas such as indoor air quality, materials and energy use. The size of the team and the aggressiveness of the design goals will determine who should be on this team.”

The Building Toolbox also urges project leaders to select team members who communicate well with one another. “The team members must keep one another up to date on design decisions so that when a decision is made that will affect the performance of another team member’s design area, the team can evaluate the consequences up front and make modifications to the design before it is too late,” it advises.

2 / Up-front preferences. The goals and considerations relating to new hospital construction or upgrades might differ between the administration and clinical staff, such as doctors, nurses and technicians. This doesn’t mean that what is important to the administrators is not important to clinicians, but that each has different priorities when approaching the building project.

Under an asset management strategy, the hospital owners will look at the integration of a solution among its components, equipment and software as well as the facility operations system. Many prefer a strategy of standardizing new HVAC installations and upgrades with one vendor. This approach generates a host of management, technology and service benefits due to consolidating on a standardized platform.

A health care provider typically has two motivations for upgrades. First is the effect on patient outcomes. Second is the ability to create and maintain a positive work environment. These concerns are related because the success of a hospital depends on the health care provider’s ability to offer medical services to their patients as well as the administrators’ ability to provide a healthy and safe work environment.

3 / The budget. The available budget for purchasing and installing the HVAC system may be imposed on the design team by the hospital administrators, or it may be developed with the aid of the design team.

If administration has determined the amount of money available to construct the building, the design team is challenged to provide an HVAC system that meets the requirements of the building with the available money. This is not always easy. Often, some requirements are sacrificed along the way because the stated requirements do not match the available budget.

4 / The design. The size, design and function of the hospital or addition can quickly narrow the choice of available HVAC systems.

High-rise hospitals are often unsuited for packaged direct expansion (DX) rooftop equipment because of the long distances that the air must be transported. In split DX systems, the allowable distance between the components of the refrigeration loop is limited to ensure reliable operation. Chilled water systems, however, are ideal for applications where the refrigeration equipment is centrally located within a hospital, or within a campus of buildings, and the cooling loads are remote.

If hospital administration does not want equipment located outdoors, it can be located in basements, penthouses or in equipment rooms for each floor. If there is limited space inside the hospital, the HVAC system may also be located on the roof, in a separate building alongside the hospital, or even at a remote location.

At the University of Kansas School of Medicine in Wichita, for instance, the existing building design was a challenge during the installation of a new chiller. In 2002, after the single chiller serving the building stopped working suddenly, Director of Facilities Management Brian Leabo began looking for a new unit that would fit the facility’s needs and solve the problem.

Because the old chiller was located in the center of the three-story building’s basement, it had to be disassembled and removed in pieces. Reversing the process, the new chiller was brought into the basement piece-by-piece and then assembled. Both old and new pieces had to be transported along a 100-yard path that included steps, inclines, declines, narrow doorways and numerous turns.

The change-out of the chiller required several doors to be widened and windows removed. The crews used forklifts, winches, carts and creative rigging techniques to complete the equipment removal and installation.

As the design process and HVAC selection progresses, be sure that appropriate space in or around the hospital has been allocated for the equipment, and that it will be accessible in the future, regardless of additions and remodeling.

5 / The function. Consider all the unique attributes of the hospital, including the medical services provided, the patients, the 24/7 operation and the numerous regulations that must be addressed by the engineered infrastructure.

These, plus specific environmental control variables, will impact the design requirements of the building environment system and HVAC selection. Some specific environmental control variables include temperature, humidity, indoor air quality (IAQ) and acoustics requirements as well as energy consumption.

Of course, IAQ can have a great impact on staff and patients who are susceptible to airborne infections and allergens. In sensitive parts of the hospital, such as pharmacies and critical care, high-efficiency particulate arresting (HEPA) filtration may be required.

Specialty function and critical care areas, such as surgical and bone marrow transplant suites, bring additional aspects to be considered, including precise temperature and humidity control, as well as HEPA filtration.

As important as it is for the HVAC system to operate at peak efficiency throughout its lifetime, it is equally important to eliminate shutdowns, which would adversely affect the performance of the hospital’s core functions as well as its overall environmental management.

By considering and planning for comfort and reliability requirements in advance, the HVAC system can be selected and designed to meet these needs on an individual as well as collective basis.

6 / Architectural limitations. Architectural issues can have significant influence in the selection of the HVAC system.

Floor-to-floor height is generally minimized to reduce construction costs, or in the case of taller buildings, to get as many floors in the building as possible. This results in limited space in the ceiling plenum. This can be particularly challenging for central air-handling systems, and may result in the use of a system in which the equipment is located closer to each zone, such as chilled water terminal units or water-source heat pumps.

Other architecturally driven issues that influence HVAC selection may include room floor plans and building structural capacity as well as indoor and outdoor aesthetic considerations. Because of the potentially immense impact of these, a representative of the architectural firm should be on the HVAC selection team.

7 / Life-cycle cost. Decisions made primarily on the installed or first cost often ignore such factors as energy use, maintenance requirements or expected life. Life-cycle cost includes the total cost of owning and operating the HVAC system over a given period of years. This includes installed cost, energy cost, maintenance cost, replacement cost and any other known and expected costs.

According to the Consortium for Energy Efficiency (www.cee1.org), the proper installation, sizing and maintenance of HVAC systems can significantly improve operating efficiency, saving up to 50 percent of energy consumption. With the right system selection and sizing, the hospital can reap significant rewards in cost and energy savings.

In 2001, for instance, the Citrus Valley Medical Center (CVMC) in Los Angeles found the return on investment when purchasing equipment based on life-cycle cost considerations can be achieved sooner than expected.

When CVMC Director of Engineering Bob James updated the chiller-plant equipment at the center’s Covina and West Covina campuses with variable-speed chiller-motor drives, he expected to see that there would be extended plant efficiency in the lower output ranges, permitting stable operation at very low cooling-load levels. The equipment manufacturers’ engineering staff calculated that there would be a simple payback of 1.8 years and an estimated annual energy savings of at least 390,000 kilowatt-hour (kWh) with the new equipment.

In 2002, the first full year in operation with the new equipment, however, CVMC saw an estimated energy savings of 521,709 kWh at each campus location, exceeding the conservative estimate of 390,000 kWh, and providing a payback that was faster than the originally projected 1.8 years.

By taking into consideration the life-cycle cost, the 500-bed, not-for-profit health care facility was able to make a needed upgrade to its HVAC system and decrease energy use by more than 130,000 kWh per campus facility.

Of course, some HVAC systems use more energy than others. The selection team will want to specify HVAC systems that offer both extensive energy management capabilities and are optimized to maximum energy efficiency to reduce utility costs.

Additionally, many state and local building codes mandate requirements for energy efficiency. Some requirements relate to the efficiency of various components, such as packaged DX rooftop units or water chillers, and some requirements relate to the design and control of the entire system. Some of these requirements even prohibit the use of certain types of HVAC systems for certain applications.

8 / Operation and maintenance. Most types of HVAC systems have some level of automatic control. The use of communicating building automation systems (BAS) increases both the efficiency and reliability of the total system because the operator can be located off-site and still diagnose the cause of a problem, just as if he or she were inside the hospital.

The most sophisticated solutions feature system integration and flexibility to enable truly centralized command and control functions ranging from the ability to change temperature and humidity settings to meet changing needs, to the environmental management of core functions, such as laundry and pharmacy, to the ability to test and balance equipment easily and efficiently.

Additional facility management factors to consider include the annual estimated maintenance and repair requirements and costs as well as the availability of options for cost-effective outsourcing, and the availability of on-call, skilled technicians.

Some local or state codes require an on-site operator for certain types of systems. These requirements are based on the capacity of the HVAC equipment. For certain types of buildings, this code requirement may cause the selection of a system that uses several smaller pieces of equipment rather than a few large pieces.

9 / Time. Finally, the speed at which a hospital must be built or renovated, and when the HVAC equipment must be installed during that process, can influence the selection of the HVAC system.

Some types of HVAC equipment are made to order and have lead times that allow for manufacturing. Equipment with factory-installed controls is often selected because it can typically be installed and commissioned very quickly. In emergency situations, equipment that is in stock may be selected for a fast-track replacement.

Analyzing and evaluating the many system choices can consume a great deal of engineering time. For this reason, it is imperative that the HVAC system design engineer become involved early in the design process. Often, the project schedule does not allow sufficient time for the design team to fully evaluate HVAC system alternatives.

When there is a great deal of pressure to quickly finalize the system choice, the hospital administrator is better served by the added engineering costs required to analyze system options carefully than to be saddled with unsatisfactory performance that will last for years.

The bottom line

It is anticipated that $200 billion will be spent on new hospital construction during the next decade, according to the Center for Health Design’s 2006 white paper, “Designing the 21st Century Hospital.”