Flues

Question 1

What are the main regulations and standards applying to flues

Answer 1

Regulations 27,30,and 32 of the Gas saftey installation and use regulations.

Question 2

BS5440 part 1:2008

Flueing and venting for gas Appliances of rated input should ot exceed

Answer 2

70KW

Question 3

Hearth are constructed to a minimum thickness of what?

Answer 3

125mm

Question 4

The concrete must extend fully into the fire recess and project at least?
And how many millimetres each side of the opening?

Answer 4

500mm in front of the jabs

150mm on each side of the opening.

Question 5

A flue serving an open solid flue fire must contain a clear circular space of at least ?

Answer 5

175mm diameter

Question 6

The need for lining in the chimney will depend upon ?

Answer 6

Type of Appliances, the input rating and the chimney height.

Question 7

What do you check whether an existing chimney or flue conforms to standards which adversely affect the performance of the flue or result on blockage.

Answer 7

Check the route of the flue(through any loft space),conditions of the flue,whether there are any changes of direction,

Question 8

Modern practice requires the flue to be constructed with one of the following

Answer 8

Brick or Masonry construction with clay lining to BS EN 1457

Brick or Masonry construction with concrete lining BS EN 1857

Question 9

What is the size of the traditional brick chimney designed to be used with solid fuel stove and open fire and is adequate for gas Appliances ?

Answer 9

225×225 (9”x9”)

Question 10

What are the three major categories of Appliances?

Answer 10

Room sealed ,open flued system, flueless.

Question 11

In a vertex flue the combustion air is drawn from where?

Answer 11

With in the loft space

Question 12

What is a forced draught?

Answer 12

This a driving force obtained from electric fan.

Question 13

What is natural draught?

Answer 13

Using thermal convection ,Driving force in order to move gases along a chimney/flue system and expel them from terminal.

Question 14

What are the 3 things that affect chimney and flue? performance
In natural draugh flue depends on?

Answer 14

# It's ability to create sufficient draught to propel the combustion gas.
# Its ability to retain sufficient heat to maintain the water vapour to prevent condensation forming within the flue. 
# the capacity to handle the volume of the gases produced

Question 15

Open flues system consists of four components?

Answer 15

Primary flue
Draught diverter
Secondary flue
Terminal

Question 16

What is a primary flue?

Answer 16

It creates the intial flue draught required to exhaust all the products of combustion.
Its often part of the chamber its self
Usually fits in to the down draught diverter.

Question 17

Any bird guard accessible to birds should have a minor dimension of not more than?

Answer 17

20mm

Question 18

Bird guard should be fabricated from

Answer 18

.corrosion and weather resistance materials

.should be securely fixed

Question 19

Terminal location of flue terminals can be found in

Answer 19

BS 5440-1 :2008