A comparison between biotech facilities and semiconductor facilities in HVAC system applications and components

Designers and owners of semiconductor facilities focus on air management issues and operational savings opportunities to stay competitive in a world economy.¹ The same concerns apply to biotech facilities. While process equipment represents about half of total project cost, mechanical systems comprise the second biggest share, about 25 percent of the total project cost.² At the same time, one needs to keep in mind that building utility and HVAC system operationalexpenditures have a great impact on the final product cost.

Getting the product out to market in time to catch the window of opportunity is the first priority for any advanced technology facility owner; therefore, the building operational costs are usually overlooked or given little attention. However, it is the engineer’s responsibility to evaluate the mechanical systems to provide reliable and cost-effective system alternatives and present them to facility owners during initial phases of the project. Yet, often the cGMP and FDA regulations, coupled with the risk of not receiving approval for the facility, prevents engineers from being innovative and looking into different design alternatives.

Both semiconductor and biotech facilities are designed from the inside out. The buildings are programmed and designed to answer process needs. Therefore, building systems are provided to support process requirements. For example, the HVAC systems are designed to meet space cleanliness, temperature,humidity, and noise level requirements forthe process. Pressure hierarchy between spaces forcontamination control and containment also plays animportant role in HVAC system design decisions. Themain goal of any good design, while maintaining theaforementioned parameters, is to provide reasonableinstallation and operational costs.

The major systems that make up the building mechanical systems are as follows:

• Chilled water generation
• Steam and heating water generation
• Make-up air (outside air) moving and conditioning
• Cleanroom air moving and conditioning This article will evaluate the mechanical systems, with a focus on air management variations. In general, cleanroom air systems consist of two major components:
• Recirculation air to provide required cleanliness level and temperature control
• Outside air to provide fresh air for indoor air quality, replenish the general and process exhaust, provide building pressurization, and establish cascading pressure control.