The one constant about technology is that it always is changing. Two major categories of technology in health-care facilities are information-technology (IT) and procedure rooms. This article will discuss the cooling of IT facilities and highlight some of the differences between IT facilities and procedure rooms.

IT spaces in health-care facilities can vary greatly, depending on the size of the facility and how progressively IT is used. Within the context of this article, IT includes computing, digital storage, digital backup, and Internet Protocol- (IP-) based networks. IP networks can include systems, such as phone systems.

IT optimization is a function of the application(s). Processing, storage, retrieval, imaging, graphics, transfer rate, latency, response time, reliability, etc. all enter into the equation regarding the optimum hardware and software configuration.

Because there are so many applications and permutations/combinations, generalizing requirements for data centers or other IT spaces is risky. This balancing or optimization can result in distributed or central computing. It also can result in off-site computing, either as a primary function or as a disaster-recovery backup solution.

While telecommunication facilities traditionally do not use raised floors, data centers do, although there certainly are plenty of exceptions. IT closets, such as intermediate-distribution and main-distribution frames, typically do not use a raised floor.

LIFE-CYCLE MISMATCH

One of the biggest pitfalls is the life-cycle mismatch between cooling equipment and IT equipment. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), it is common for cooling equipment to have a projected life of 15 to 25 years. It is common for IT equipment to have a projected useful life of three to five years. Therefore, cooling equipment potentially can serve four or five generations of IT equipment; this represents an incredible challenge.

Often, data-center cooling is predominantly sensible cooling. As a result, cooling equipment that is particularly effective in high-sensible-heat-load conditions can be a good choice. Often, these units are referred to as CRAC (computer-room-air-conditioning) units.

CRAC units are best evaluated and tested using ANSI/ASHRAE Standard 127, Method of Testing for Rating Computer and Data Processing Room Unitary Air Conditioners. This standard includes important performance information, such as sensible coefficient of performance.

TYPICAL IT CLOSETS AND ROOMS

Even in new facilities, IT closets seem to be more of an afterthought than optimally located. They can be somewhat stranded with little room for cabling infrastructure. As a result, a cooling system may become more of a retrofit than a planned, integrated solution. The typical pitfalls associated with IT closets include:

• No consideration for IT-closet upgrades or changes, such as in cabling or equipment.

• No redundancy in power and cooling services.

• No consideration for cooling services on emergency power.

• Little provision for ease of maintenance or concurrent maintenance and operation.

IT closets typically are cooled with spot cooling or by extending the cooling system in the general area to the IT closet. Because of the often tight space constraints and overall small total tonnage, oversizing/undersizing is a significant risk, especially as upgrades are made in an IT rack without facilities engineers being adequately informed.

Computer rooms often are small compared with data centers for other applications, except for large medical facilities, campuses, and multiple locations. Typically, the smaller the data center, the more difficult it is to provide the level of redundancy, the ability to continue in full operation during equipment servicing, and the ability to handle varying loads/upgrades. The typical pitfalls associated with data centers include:

• For raised-floor systems, a tendency for the raised-floor plenum to have inadequate air-handling capacity because of height, congestion, or leaks.

• For overhead systems, a tendency to have inadequate flexibility to reconfigure or redistribute as IT upgrades occur.

• Inadequate cooling-equipment redundancy, concurrent maintenance provisions, or provisions for load growth.

• Cooling services derived from cooling systems in the area not having adequate availability 24/7 and/or being too dependent on conditions outside of the data center regarding capacity and operation. For example, a system may use primarily chilled water during cooling months and an air-side economizer at other times.

• IT equipment not being adequately planned to establish a hot-aisle/cold-aisle configuration to avoid supply- and exit-air contamination at the IT-equipment level.

• IT loads essentially being all sensible (different sensible-heat ratio than most other loads in a hospital). Equipment designed for high sensible loads is critical.