OPERATING PROBLEMS CAUSED BY DRAUGHT DEFECTS IN THE FLUE. MCZ SAGAR, MUSA, TOBA, Suite, Club, NIMA

PELLET STOVES

INSTALLATION AND USE MANUAL

Chapter 2 page 15

This type of connection ensures the evacuation of the fumes even in the event of a temporary power cut.

2.9. OPERATING PROBLEMS CAUSED BY DRAUGHT

DEFECTS IN THE FLUE

E.g. Downdraft at 45° of

8m/sec. Overpressure of 17

Pa

Of all the weather and geographical conditions which affect the operation of a flue pipe (rain, fog, snow, altitude a.s.l., exposure to sunlight, direction of facing), the wind is unquestionably the most decisive. In fact, along with thermal depression caused by the difference in temperature inside and outside of the chimney, there is another type of depression or over-pressure: dynamic pressure caused by the wind. An updraft always increases depression and hence draught. A crosswind increases depression provided the cowl has been installed properly. A downdraft always decreases depression, at times inverting it.

Least favourable points Most favourable position

WIND

High-pressure Low-pressure zone

Besides the direction and force of the wind, the position of the flue and the cowl with respect to the roof of the building and the surrounding landscape is important.

The wind also influences the operation of the chimney indirectly by creating high-pressure and low-pressure zones, not only outside the building but inside as well. In rooms directly exposed to the wind (2), an indoor high-pressure area can be created which can augment the draught in stoves and fireplaces, but it can be counteracted by the external high pressure if the cowl is situated on the side exposed to the wind (1). On the other hand, in the rooms on the opposite side from the direction of the wind (3), a dynamic depression can be created which competes with the natural thermal depression developed by the chimney, but this can be compensated for (sometimes) by locating the flue on the opposite side from the direction of the wind (4).

IMPORTANT!

The operation of the pellet stove is noticeably sensitive to the conformation and position of the flue which is adopted.

Hazardous conditions can only be overcome by suitable setting-up of the stove carried out by qualified MCZ personnel.

E.g. Crosswind 2: 8 m/sec

Depression of 30Pa

WIND

1

2

Downdraft

3

1-2 = High-pressure zones

3-4 = Low-pressure zones

4

Theoretical notions for installation Technical service - Rights reserved MCZ Group S.p.A. - Reproduction prohibited