Copper has a thermal conductivity of 401W/mK, which, when compared to Stainless Steel with a rating of 14W/mK, makes it easy to see why copper is the material of choice

One of the other main advantages of using Copper Cylinders with Heat Pump Systems is that it has natural antibacterial properties.

Due to the way Heat Pumps work, they typically heat water to a temperature of between 45-55 degrees, which can provide a breeding ground for bacteria such as Ecoli and Legionella.

Copper will eradicate MRSA, E-coli and Avian Bird Flu in under 5 Hours (1). In tests it took 34 days for E-coli 0157 to die on Stainless Steel, 4 days on brass and just 4 hours on copper (2) 99% of the bacterial population introduced into a copper plumbing system, will disappear in under five hours. Copper is recommended to combat Legionellae.

Add in the fact that copper offers a far greater degree of manufacturing versatility for the sizing of the cylinder and the fact that copper has an exceptional resistance to corrosion to ensure that the hot water cylinder continues to perform for years to come.

And if that wasn't enough, over 90% of all copper is re-used over and over again, making it the ultimate choice as well as environmental and economic sense.
 

Source:   Air Source Heat Pump , Heat Pump

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