Issues for Good Chimney Design

These are the main issues to consider in chimney design and the way to avoid problems.

1.  Flue Gas Temperature

Poor or No Insulation can result in a dramatic reduction of flue gas temperatures significantly reducing the performance of the appliance and causing condensation.

Solution: Consistant quality insulation throughout the height of the chimney as provided by the Schiedel Chimney Systems, will maximise the discharge of the flue gases.

2.  Acid Resistance

When the gases condense they form a strong acidic solution on the walls of the flue.

Solution: The consistant insulation throughout in the Schiedel Chimney System will help prevent the gases condense. Should an acidic solution build up the acid resistant nature of clay liners will minimise the impact of the acid.

3.  Soot Build Up

Soot and condensate deposits form on the inner wall of the flue liner. These deposits can re-ignite and cause a chimney fire.

Solution: This is an area where clay liners outperform concrete. The smooth surface of the clay liner is less likely to encourage soot build up.

4.  Heat Resistance

Excessive temperatures caused by soot fires can crack the flues & brick work  leaving the chimney exposed to leaks and moisture penetration.

Solution: The new European standard for ceramic flue liners has increased the temperature resistance of clay liners. 

5. Thermal Stress

The flue liner needs space for expansion &
contraction.

Solution: The flexible insulation in the Schiedel Chimney System allows the liners to expand and contract safely.

The expansion plate also allows the liners to safely expand & contract vertically.

6. Flue Design

 Bends reduce the performance of the chimney.

Solution: Design the chimney as straight as possible. 

7. Water Ingress

Without  protection water can penetrate through poor mortar joints or porous brick onto the chimney breast.

Solution: Chimneys trays should always be used with brick work.