Hello, I am new here. I am the engineering manager for a company that manufactures compressed air powered cooling devices (vortex tubes). These vortex tubes are commonly used for cooling personnel in sand blasting, painting, welding and other hot or nasty environments-cold air is generated by the vortex tube and fed into an "air vest" that is worn under the user's protective clothing. Many of the well known respirator manufacturers also use our vortex cooling tubes in their Supplied Air Respirators to cool the breathing air. My questions are: would / could a compressed air powered cooling product be used under arc flash suits to keep the user comfortable? (Keep in mind the user would be attached to a compressed air hose anytime cooling is required. Typcially these vortex tubes will require at least 15 cubic feet per minute (cfm) compressed air at 80-100 psig to cool effectively.) What Hazard Risk Category PPE would this type of cooling most likely to be used with? What regulations would this type of product need to comply with?
What are the pros and cons, as you see it, of this type of compressed air powered cooling?

I am familiar with the "gel pak" type cooling vests and the battery powered fan driven hood ventilating products.

Thanks for any insight you can give!

Steve

Hi Steve,

HRC 3 and up I can definitely see cooling be an advantage when wearing PPE for prolonged times, and even HRC 2* (wearing a balaclava) under hot circumstances.

NFPA 70E section 130.7 covers what you can and cannot wear under your arc rated PPE. The main requirement is that the material does not melt at high temperature, which may be an issue for you. The 2012 version of the standard is to be released in october, but you can already view it online (read-only) at nfpa.org. There are some specific types of disallowed garments mentioned there so you should review these carefully.

Pros: reduce the heat hazard for workers wearing PPE in unfavourable conditions. Switchrooms are hot and HRC 4 PPE quickly gets uncomfortable even at room temperature, and their use cannot always be avoided.

Cons: 1. more hassle for workers (at the risk of them not using it). 2. Heat hazard isn't the only downside to higher-HRC PPE, for example restriction of movement and visibility are also introduced (and may even be worsened by your product). PPE should of course be viewed as a last resort measure, but employers might use this as a crux to have workers using them for prolonged times and engage in activities where better solutions of risk-management exist.

Disclaimer: I'm not in the US so I might be forgetting some standards, this is just off the top of my head.

PPE for Cooling

I love the vortex options. DuPont put these in a suit many years ago and I have worked with others trying to retrofit. If you are selling them, they should be built into the suit.

Standards are ASTM F1506 and ASTM F2178 for the hood. I don't think they would require a full rating but the system should be evaluated to assure they don't "increase the extent of the injury" in the arc event and be tested using ASTM F2621 and probably ASTM F2178.

We do most of the testing and I'd be happy to assist.