Yes, You Can Save Energy AND Maintain ISO Requirements!

26 May 2023

Climate change is making daily headlines around the world, and biopharmaceutical companies are taking note -adding sustainability goals to their company strategies. This may not be a surprise when it comes to larger global facilities, but 79% of startup companies are doing the same. These changes can also help reduce the operational costs of facilities. Biopharma HVAC (heating, ventilation, and air conditioning) systems account for nearly 60% of the industry’s energy use, using higher air change rates and lower temperature and humidity set points than commonly used in the larger industrial world. Cross-contamination concerns also tend to be more conservative due to the concerns for customer safety and the high cost of product loss should a contamination incident occur.

The good news is that energy usage can be minimized by making careful and specific choices in design and operations. Our clients often request the most conservative HVAC approach possible in terms of cross-contamination without completely understanding the energy that is often wasted in such designs. You can reduce energy usage and maintain contamination risk requirements, meeting corporate energy standards and saving money. Here are some strategies you can use to preserve required cleanliness while decreasing energy use:

  1. Share your concerns with the engineers and architects building your new or retrofitted facility. It’s imperative to go over every possible detail during the planning stage so that there are fewer problems and expenses later in the process. Your process and quality control experts should work with your engineers to create the best possible design for your needs. Remember, you don’t have to be overly conservative.
  2. Choose a system using recirculated air instead of a single-pass HVAC design whenever possible. A recirculating system uses less energy, and it also results in a significant reduction in the size of the central heating and cooling plant.
  3. Check the air change rate in your clean rooms. In existing Biopharma plants, air change rates of 60 for ISO 7 and 30 for ISO 8 are common. But companies that studied their energy usage found they could reduce these rates by at least 30% without compromising cleanliness, maintaining the lowest rate necessary to meet required ISO grades.
  4. Use swirl diffusers on the ceiling HEPA filters in the clean rooms. This provides a much better distribution of clean air, which allows a lower air change rate to meet the same cleanliness level.
  5. Investigate how low your humidity set point needs to be. Sometimes it is set at 50% RH, which may be unnecessarily low. Consider using a set point of 60% RH or even 65% RH, saving energy but preventing mold growth.!
  6. Stop using the same air change rates 24/7. Consider reducing air change rates during off-hours when production is not underway and personnel are not entering the clean room. Consider using particle counters to actively control air change rates.
  7. Take advantage of free cooling (air-side economizing) in recirculation systems when outside air temperature and humidity permit. Biopharma plants typically do not use air-side economizing due to concerns about compromising the clean room pressure controls; with careful tuning of the controls, it should be possible to successfully implement air-side economizing, reducing the cooling energy usage considerably.
  8. Use real-time energy consumption data to optimize the lead-lag control of multiple chillers and boilers in the central plant. The energy efficiency of these machines varies with load, and this information should be used in determining how many should be running for a given load in the plant.
  9. Focus on maintaining a corporate culture that understands the need to save energy when possible – both for sustainability goals and reducing energy costs. Ensure your entire workforce understands the importance of reducing energy use.

Today’s biopharmaceutical industry is one of the most regulated in history, and for good reason. Avoiding cross-contamination is critical to creating viable drug therapies that are both safe and effective. While minimizing contamination risk seems to be at odds with saving money and creating a sustainable facility, it is possible – even preferable – to find the balance and maintain a successful business.


*ISO = International Organization for Standardization

! RH = Relative Humidity