EVA Stampaggi HYDRO CURVED FRONT 20 KW, Instruction Manual

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03. INSTALLING THE PRODUCT
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03.5 STOVE EFFICIENCY
Highly efficient stoves may pose difficulties for fume extraction.
In order for a vent pipe to work properly its internal temperature must increase as a consequence of the fumes generated during
combustion.
Importantly, the efficiency of a heater is determined by its ability to transfer most of the heat produced to the environment to be
heated: consequently, the greater the efficiency of the stove, the "colder" the residual fumes of combustion, and consequently, the
lower the "draught".
A traditional chimney flue, with a rough design and insulation, is more efficient if used with a traditional open fireplace o r a poor
quality stove where most of the heat is lost with the fumes.
Therefore, purchasing a quality stove often entails modifying the existing chimney flue to obtain a better insulation, even when it
already works properly with old appliances.
Poor draught results in the stove not operating when hot or in smoke spillage.

Connecting the stove pipe to an existing chimney flue that has already been used with an old appliance is a common mistake.
In this way two solid-fuel appliances share the same chimney flue, which is wrong and dangerous.

If the two appliances are used simultaneously, the fume load might exceed the existing chimney flue capacity resulting in
downdraught. If only one appliance is used, the fume heat will facilitate draught but the cold air coming from the other
appliance not in use will cool down exhaust fume temperature again blocking the draught.

Besides the problems described so far, if the two appliances are placed on different levels the communicating vessel
principle might be interfered with, causing combustion fumes to be drawn in an irregular and unforeseeable way.