The standards for refrigerant safety require that chiller pressure relief devices (rupture disks) be piped outdoors, so that a catastrophic overpressure is vented instead of being contained in the equipment room. Do you know the reasoning behind this?

When a pressurized refrigerant charge escapes, the refrigerant gas tends to push the air out of the room and dilute it to a very thin mixture. If the quantity of refrigerant is large enough, there may not be enough oxygen left to support respiration. Thus, a non-vented leak can be harmful or fatal to humans. Leaks due to blown rupture disks will normally be vented outdoors. However, non-vented leaks due to failed gaskets, o-rings, and even damaged piping can deplete the air from a room very quickly.

Non-vented refrigerant leaks can have another adverse effect in the mechanical room. Just as they deprive us of oxygen to breathe, leaks can also deprive a gas burner of the oxygen it needs for combustion. Larger boilers have optical (instantaneous) flame safeguards to prevent explosive conditions in the furnace when the flame is snuffed in this manner. Smaller boilers and water heaters, though, often rely on safety features with inherent time lags such as thermocouples. The gas will continue to flow without flame for some period of time, and if oxygen is restored before the firebox temperature falls below the ignition temperature of the mixture, a furnace explosion will result. In the best case, the result is a funny-shaped heater. In more severe cases, fire investigators stand around the empty slab and try to figure out what happened.

All of these potential adverse effects are reasons to invest in a Kele refrigerant monitor. On a rise in refrigerant level, these units can be connected to start ventilation fans, and also to trip fuel shutoff valves until the furnaces can be manually purged of explosive mixtures. The RLD-IR, RLD-5, and RLD-134A refrigerant leak detectors can help minimize the time that the room is starved of oxygen, and can also help minimize the potential damage from a leak when the burners are firing. Call your Kele sales associate today to order these reliable sensors!

by Dave Weigel