Cleanroom HVAC Strategies

[The following abstract of an article on HVAC design for cleanrooms and controlled environments is highly technical and the field…as technology is in general…is dynamic and continuously evolving.  It offers an excerpted overview of several key considerations.  Ultimately, your project’s unique properties…especially those of your process, product, research requirements and your physical plant…will determine best practices.]

Cleanroom HVAC design has two (2) critical concerns that can be considered different perspectives on on the same issue:

  1. Contaminants
  2. Control of the Environment

If the war on these manufacturing enemies are not won in the design process, the result can be millions of lost dollars due to insufficient product yield and compromised product integrity…hitting a company’s bottom line forcefully.

Optimal HVAC design solutions are determined by desired temperature and humidity control, air flow and pressure, and filtration requirements and air change rates…at the very least. These design factors are dictated by the requirements unique to your process, facility, and regulatory requirements.

Whether creating a controlled environment for an electronics manufacturer or a life sciences environment free of pathogens, the HVAC system controls your success and will significantly impact your operating costs.

Three (3) contamination fundamentals must be considered…regardless of the degree of desired air quality and cleanliness:

• Contaminants are never beneficial…begin by preventing their passage from outside into the work environment.
• Those that infiltrate your environment must be eliminated quickly.
• Besides worrying about particulate interlopers from the outside environment, make sure you have your own house in order. This means minimizing contaminants that your manufacturing or research processes—including the equipment integral to your operations—throw off, whether through biological, chemical, or operating processes. And make sure your employees consistently follow protocols developed to minimize contamination.

Cleanrooms demand an estimated 10 to 100 times more energy than standard office spaces…due to strict air cleanliness standards—and the HVAC system can account for more than half of the facility’s energy costs.  Following are a variety of strategies to help reduce energy costs related to your HVAC system:

  1. Minimize Demand. Take a look at your building. Can you increase the efficiency of the shell? When building new, carefully orient and develop the building form. Is there an opportunity to reduce the volume of your cleanroom? Less volume equates to less air re-circulation with resulting HVAC savings.
  2. Accurately scope the level of cleanliness and the square footage required. Going overboard in either category will drive up your costs. Considering reducing positive pressurization where prudent.
  3. Flexibility is key. Design your HVAC system with an eye towards flexibility, not only for sustainability, but for future product line and expansion capabilities as well. Remember to accommodate part load scenarios in HVAC equipment purchase.
  4. Subdivide your facility’s space classifications. Carefully examine the proposed process and product requirements when determining your required cleanroom classification. Don’t shoot an ant with an Uzi. Do you really need the entire space to be stringently controlled?
  5. Mini- and micro-environments are your friends; stick or prefab? Consider the use of micro- or mini-environments (see the May 2013 issue of Controlled Environments) and a mix of stick built and prefabricated areas—determined by process specifications and flexibility needs. Utilize these tools to meet your process requirements instead of upgrading your entire cleanroom.
  6. Invest in high efficiency equipment. Upfront costs are an investment with surprisingly short payback periods.

Read More – Controlled Environments