Cleanrooms by Type


Cleanrooms are typically divided into various types of design. The first and most prevalent cleanrooms are the bay and chase arrangement. The bay is the clean area where the clean air is driven through the filters and returned through the chases, return walls or return ducts. The chase is where the dirty end of the manufacturing equipment is placed and utilities are placed to service the clean bay. This approach can be done with either a wall return or a raised access floor return.

The second type of cleanroom approach used in large manufacturing facilities that require a cleanroom classification of 100 and better air, is the ballroom approach with a flow through floor. This approach typically has a positive plenum ceiling driving air through the entire cleanroom via a raised access floor and to a return level under the floor that goes back to the plenum above.

Cleanroom engineering also takes place in large open space cleanroom applications for class 100,000 and class 10,000 where laminarity is not an issue as in the ballroom approach. In this case, the air delivery system uses either central fans or fan filters placed to drive the air in a random flow pattern back to the ducted or plenum return system.

Isolation rooms and laboratories: Some industries require multiple zones of pressure control and rooms for isolation for different clean areas based on the function and the process at each area. These areas are typically divided into smaller suites involving air locks with positive and negative pressure and are based on trapping contaminants in various rooms and preventing cross contamination. These rooms typically involve multiple isolated air streams using ducted supply and ducted return so that the pressure differential can be set up and accurately controlled. Control at supply and return to each room is crucial.

Design/Build (Turnkey) Cleanrooms

Cleanroom construction and design are typically considered specialty trades. HCC can provide complete turnkey cleanroom design and build services.

Pre construction services include:

  • Analyzing program requirements
  • Determining the level of cleanliness needed
  • Deciding what type of cleanroom will be the most efficient and cost effective
  • Identifying the types of materials and systems to be integrated in cleanroom construction

Hodess takes this information, analyzes the variables required for the process, and establishes a base line program to review with you.

Once everyone has agreed that the plan will meet the requirements of the process to be done in the cleanroom, HCC progresses to 30% design stage and establishes a guaranteed maximum price as well as schedule for the project. The design is reviewed with you and, once approved, we proceed to a 60% design phase. Design is reviewed again before we progress to 100% construction and documentation.

We have the ability to provide stamped documents, code analysis, structural design and all services required for the complete installation of a cleanroom from a simple modular free standing cleanroom in open space, to complicated integrations, structural modifications of existing buildings and existing mechanical systems.

Cleanroom Envelopes

Hodess Construction Corp. has provided cleanroom construction management services and general contracting services for cleanroom envelopes. A cleanroom envelope is the construction of the cleanroom walls, floors and ceilings without the full mechanical, electrical, and process typically under the control of the cleanroom contractor. We have provided cleanroom envelopes involving drywall perimeters along with modular panels, gel sealed plenum ceilings for delivery and plenum returns, raised access floors and modular cleanroom walls.

The cleanroom envelope is typically a subcontract integrated into an entire building project where a construction manager or general contractor is providing the mechanical, electrical and process services to the cleanroom, and the envelope contractor must integrate with the general contractor and his subcontractors.

Modular Cleanrooms

Modular cleanrooms have been used in many industries for the past 30-years. Modular components such as wall systems, started out as modifications to office partition type systems like the steel Donn wall system, and progressed to specific systems for various industries and cleanliness levels. Modular ceiling systems have progressed from grid to modular panels to modular plenums and from dry seal to gel seal and spring loaded grids. Modular components also progressed for raised access floor for class 100, class 10 and class 1 cleanrooms where air flow is required to be totally laminar throughout the process.

A complete modular cleanroom is typically built with the walls as a modular system, a plenum supported by the modular walls, ceiling system supported by the plenum cap, and fan filters driving air through the modular cleanroom. Modular cleanrooms can be applied to both small and large facilities. The cost effectiveness to modular cleanrooms varies depending on the type of facility and the magnitude of space in which the modular cleanroom is applied. Modular cleanrooms typically provide a more standardized package and modular components tend to cost more than stick built but save on field installation labor.

Plan and Specification Cleanrooms

Hodess provides cleanroom construction services for projects that are already designed. We can provide a full turnkey approach for plan and specified cleanrooms providing competitive bid hard numbers, cleanroom management services on an open book basis, or variations of these services.

Plan and specification cleanrooms typically provide full sets of drawings and documentation, which are available for the cleanroom contractor to put a hard number on and to take for permitting. In the plan and specification mode, the analysis of your requirements, the cleanroom requirements and the variables have been done by a third party and not the cleanroom construction contractor.

Stick-Built Cleanrooms

At first, all cleanroom environments were stick-built. Aside from today’s modular components such as wall systems, ceiling systems and floors, cleanrooms were built using standard building materials. In today’s market, many larger cleanrooms and class 1000, 10,000 and 100,000 cleanrooms are still stick built using predominately standard building components. Drywall partitions with epoxied paint surfaces are adequate in many cases for the cleanliness levels from class 1000 to class 100,000. Ceiling systems of steel and aluminum using gasketed grid and non-shedding tiles are also sufficient in many of these cases

Stick-built cleanrooms have an advantage in some cases over modular cleanrooms in their ability to be used over a large area at very economical prices. Stick-built cleanrooms can also have exterior walls that double as fire rated partitions to break up building areas. Some modular partitions are also fire rated. Stick-built cleanrooms are used in many industries and the determination of whether to go stick built or modular is typically done on a cost benefit analysis. Stick-built cleanrooms tend to have air delivery systems of ducted supply, ducted return or ducted supply and plenum return or sometimes fan filters (See descriptions of these systems under cleanroom air delivery types). We have delivered many stick-built cleanrooms over the years and see a strong trend towards stick-built using modular components (See stick-built modular cleanrooms).

Stick-Built Modular Cleanrooms

Stick-built modular cleanrooms combine the stick-built and modular approaches. The use of modular walls as either the primary perimeter or as a lining on a stick-built system allows the benefits of a stick-built approach, creating a sealed perimeter to the cleanroom and a fire rated perimeter in many cases. All the while using the cleaner, less shedding surfaces of modular panels. In today’s market, modular panels consist of various products, including:

  • Aluminum honeycomb panels with epoxy finishes and UPVC finishes both freestanding modular and ½” modular for stick application laminate panels both solid and particle core
  • Laminate panels including foam cores for structure
  • Hard board with painted finish on foam panels
  • Steel panels with epoxy finish and many others

Stick-built modular cleanrooms combine these components along with the modular grid systems using the dry seal 2” aluminum or 1-1/2” aluminum system or a gel seal system using either modular plenums or field built plenums composed of the stick built perimeter wall. The other choice is to use modular panels as a ceiling system to create a walk on mezzanine as well as a non shedding ceiling. Stick-built modular cleanrooms tend to provide the benefits of the flexibility of the stick-built systems, cleanliness of the modular systems and cost effective cleanroom construction.