Interested in explosion-proof HVAC in other industries? Read more

Explosion Proof Hvac Unit

The Challenge:

Air Innovations’ Cleanroom Systems division was asked to design a Class I, Div I Enclosure. This form of environmental control system (ECU) is used to control the process air needed for solvent-based coating of pharmaceutical tablets. The final environmental control solution needed to dehumidify the ambient air in a single pass (versus re-circulating air) – which is a critical parameter for the fluid-bed coating process – in an explosion-proof environment.

Download our pharmaceutical whitepaper: A Healthy Environment

The Solution:

We configured the explosion-proof air conditioner to provide once-thru air to a single LDCS-PRO coater. The explosion-proof HVAC system was designed for near continuous operation to ensure a non-condensing environment and to provide thermal stability. The electrical panel, humidifier, and compressor are encased inside the pressurized cavity of the ECU to protect against sparks, to keep out volatile gases, and to remain isolated from other compartments.

Key Specifications:

  • Ambient inlet conditions range from 21°C to 24°C temperature and from -12°C to 16.7° C dew point
  • Design output conditions maintained at 22°C ±2°C temperature and at 10°C ±1°C dew point
  • Ambient change rates over a 1-hour period are no more than 1°C temperature and no more than 5% RH
  • Electrical and mechanical sections are pressurized with purge gas via a Cyclops system, with max external static pressure 0.5”
  • System airflow 750-1000 CFM
  • Fan is an explosion-proof direct-drive impeller wheel
  • The heater is a 5.0kW electric reheater, Class 1 Division 1, Groups C&D, T2D (max 215⁰C)
  • UL approved

The Result:

  1. All design specifications and parameters were met, incl. Class 1, Division 1 requirements (for the fluid-bed coating applications)
  2. The explosion-proof air conditioners were designed for near continuous operation, as outlined.
  3. All controls were mounted behind a viewing pane.
  4. Stainless-steel construction
  5. First piece delivered in 5 months (within quoted lead time).

We have whitepapers available covering the aerospace industry, the semiconductor industry, and our Micro Environments product line in addition to our case studies. The whitepaper page can be found here. If you would like to see case studies for other industries, view our general case studies page. If you are interested in reading more case studies for the pharmaceutical industry, look at the items below.