When designing a cleanroom, the first question we ask is what is the exhaust coming out of the room? Then we ask is there any process exhausts, or is there a biological safety cabinet that has a lot of exhaust that has to go outside the building?
If we have to bring air in to make up for the exhaust, that make-up air has to be conditioned.
That is the biggest energy consumer and the most expensive part.
Temperature Control and Make-up Air
Make-up air can be a big cost dragger. Over the summer, you're bringing in 30-35°C worth of hot and humid make-up air into the building, and you want it at 20°C. That's a lot of energy to cool it down.
You’re faced with the same thing in February when its -20° C. That’s even more energy to heat it up about 40 degrees warmer.
Can we reclaim some of that heat or cooling using by-pass heat exchangers, or additional heat exchanger coils, or things like that? You can be more efficient by reclaiming some of that energy.
The higher the classification, the more air changes,
If you've got a higher class (like an ISO 4 or 5 level room) you have to increase your air changes, which can be up to hundreds of air changes per hour.
That takes a fair amount of energy. We look at that and recirculate that air as much as possible and then just bring in the minimum amount of make-up air required for the process, or occupancy.
It’s not about making the room as small as possible, it’s about making it as efficiently-sized as possible.
We really focus on the process going into the space. What are the critical parts of that process and are there any parts that need a higher classification? Then, we try and minimize that space and volume around it as much as possible.
The other thing is utilizing fan filter modules. We have a product called SmartHEPA that we build ourselves, which is a fan attached to a smart HEPA filter.
Basically, this is a small box above the ceiling, where we provide conditioned air into the room. But then, air moves up through the walls, returns through the walls into the plenum space, and then recirculates back into the room through the filters.
Do We Really Need 24/7?
Right now, we’re seeing the industry ask if they can dial back the rooms at night. They’re not using those rooms a hundred percent of the time.
When the rooms are not in use, do you really need to have a hundred air changes per hour? Could you dial it back to twenty or thirty air changes per hour? And then when it goes into use, you ramp it back up.
That's a tougher one to validate in some of the more heavily regulated industries. The classic approach is the more interchanges the better, so that is still the norm.
We use LED lights with very little energy required.
We have a new product that’s integrated right into the T-bar in our ceiling. They're not the big white panels. This allows for a service-walkable ceiling. There are no areas that you can’t step on if you need to walk on them for servicing.
Of course, the biggest X-factor will always be the number of human beings that will be in the room and what they will be doing.
We always start with the client's process. What is it that they're trying to accomplish? Next, we look at the major pieces of equipment or workstations that need to be incorporated into this space.
Once we know this, we try and lay those out in a linear fashion, or a U-shaped fashion, so you've got unidirectional flow through the facility.
The Room’s In-Process
Now it’s time to start looking at the materials used and personnel flows through the facility. Where do the materials come in? Where do the people come in?
Typically, materials and people are separated, just from a contamination perspective. You would have materials sent into an airlock and they would be decontaminated
Now, what’s the in-process? Where does the material move during the process from one workstation to the next? Is it all automated?
We’re trying to minimize travel time in the space, again, because that comes back to the energy efficiency. If you minimize the space, you minimize the number of air changes and volume.
With a unidirectional flow, the key is really to minimize travel times and then also minimize the crossing of materials or people as they go through the process, so you can reduce contamination risk.
And finally, how do you get finished goods? How do you get waste materials out? How do you get parts or equipment in and out? If you have equipment that needs to go out to be autoclaved or sterilized outside the room, how does it exit and come back in?
We look at applying manufacturing concepts, in terms of minimizing travel time, changeovers, placing workstations in linear or U-shaped cells.
As you can imagine, it’s hard to list everything we think about and every calculation we crunch in a single blog. If you have any questions about our process, by all means, reach out to us at any time.
ALUMA1 Modular & Flexible Cleanroom Systems are the go-to choice for organizations with demanding cleanrooms, such as Dalton Pharma, PharmHouse, and Baylis Medical.
Ready to discuss your project? You can reach out to us at [email protected] or by calling 1.866.625.8621.