Calefactio’s Flow-Through Expansion Tank Helps Minimize Legionella Bacteria Growth

BLAINVILLE, Quebec –Water quality in domestic hot water distribution systems becomes an increasingly present concern in the design of plumbing systems, especially since the outbreak of numerous cases of Legionellosis. This concern is all the more vital considering that the temperature of water in these systems is at an ideal range for the propagation of the bacteria. Calefactio is innovative in this with a flow-through expansion tank for potable water.

The new flow-through expansion tank for potable water avoids water stagnation in the bladder since its design allows continuous flow. Its operation is the same as a standard expansion tank; the bladder accommodates the expansion of the water, avoiding a rise in pressure which would be dangerous for the system. However, the design of the Calefactio flow-through expansion tank for potable water ensures the system water circulates at all times, from the entry to the exit of the tank, unlike an in-line tank which will retain a certain amount of residual water which will stagnate at the bottom of the bladder.

Legionellosis can be contracted by inhaling water droplets infected with legionella bacteria from a faucet aerator or from mist from a shower. The bacteria then lodge in the lungs, leading to infection with symptoms similar to pneumonia which can be fatal.

The bacteria develop in stagnant water at temperatures between 68 F and 122 F. With these conditions being common in domestic hot water systems, it is important to protect against the colonization of the bacteria which multiply exponentially each minute. One means to counter the propagation of this bacteria is to minimize the stagnation of the water in the tank with a Calefactio flow-through tank, since the flow destroys the biofilm where the bacteria could grow.

Download Calefactio’s white paper for more detailed information about the threat and the possible solution.