MCZ Philo User Manual

Page 15

PELLET STOVES

Chapter 2

USE AND MAINTENANCE MANUAL

page

Theoretical recommendations for installation

2.9. OPERATING FAULTS ASSOCIATED WITH

DRAUGHT DEFECTS IN THE FLUE PIPE

Among all the weather and geographical conditions that have an impact

on the operation of a flue pipe (rain, fog, snow, height above sea level,

sun-shy periods, exposure to cardinal points etc.), wind is certainly the

most crucial. In fact, as well as thermal depression induced by the

difference in temperature between the inside and the outside of the

fireplace, there is another type of depression (or surpression): dynamic

depression induced by the wind. Ascending wind always has the effect

of increasing depression and therefore draught. Horizontal wind

increases depression if the chimney is installed correctly. Descending

wind always has the effect of decreasing depression and sometimes

inverting it.

As well as the direction and strength of the wind, the position of the

flue pipe and chimney in relation to the roof of the house and

surrounding landscape is important.
Wind has an impact (even indirectly) on the operation of the flue,

creating areas of surpression and depression both inside and outside

homes. In environments directly exposed to wind (2), an internal

surpression can be created that can encourage draught in stoves and

fireplaces. However, this can be contrasted by external surpression if

the chimney is positioned on the side exposed to the wind (1). On the

other hand, environments facing away from the wind (3) can create a

dynamic depression that competes with the natural thermal depression

developed by the flue. However, this can be compensated (sometimes)

by positioning the flue pipe on the opposite side to the direction of the

wind (4).

IMPORTANT!
The operation of the pellet stove is greatly affected by

the conformity and positioning of the flue pipe used.
Precarious conditions can usually be resolved by

setting the stove appropriately. This must be done by

qualified MCZ staff.

E.g.: Horizontal wind at
8m/sec. Depression of 30 Pa

E.g. Wind descending at 45°
and 8 m/sec. 17 Pa
surpression.

1-2 = Surpressed zones
3-4 = Depressurised zones

WIND

Least favourable points

Most favourable position

WIND

Descending wind

Pressurised zone

Depressurised zone