ULTRAMAX PB 65 - 120
14 L290 ©MHS Boilers 13/12/2010
3.0 General Requirements
3.1 Condensing Boiler
In condensing boilers, residual heat is extracted from the exhaust gases through cooling and condensation
and subsequently fed back into the heating system. This ensures a high degree of efficiency and low energy
consumption.
3.2 Chimney Notes
Exhaust vents must be installed in a shaft or chimney compliant with the prevailing Standards and Codes of
Practice.
The low flue gas temperature and residual fan pressure prevail ant with the Ultramax PB boilers, place
specific design requirements on the chimney system serving the appliance.
Examples:
The joints in flue system components must be moisture and pressure tight. The typical dynamic pressure
expected within the flue system will be in the region of 200pa.
The flue component must be manufactured from a material that will not fail when subjected to the
condense formed during the combustion process. This will be slightly acidic with a PH level between 5.5
and 7.0.
Flue system components must be selected, sized and designed to meet the specific requirements of the
boilers and site conditions. If there is potential for the condensate formed within the flue system to be
exposed to sub-zero temperatures, provision must be incorporated to ensure that freezing does not
occur.
Suitable access must be made available to allow all joints within the flue components to be inspected as
a part of general maintenance procedures
3.3 Prior to assembly of any condensing boiler, always check the exhaust vent system.
Dimensions shall be applicable to the use of a polypropylene (PPS) exhaust system in pursuant to the
prevailing Standards and Codes of Practice. The low exhaust temperatures require commercially available
exhaust vents applicable to condensing boilers.
Examples:
- Chimneys resistant to moisture
- Interior shells resistant to condensate
- Certified exhaust vents
- Diameters of connectors (sleeves) must be taken into consideration for minimum shaft diameters.
3.4 Condensate
The connection of the condensate discharge (behind boiler) must be sloped into the discharge line.
The location of condense pipework must be protected against freezing within tundishes, traps and pipework.
The condensate may be discharged into the foul water system subject to National or Local Regulations.
3.5 Exhaust venting
Conduit pipes and sections must be
- freely accessible and available for inspection from outside the shafts and must be protected from
freezing.
3.6 Exhaust vents
- must be resistant to moisture
- must be suitable for exhaust temperatures below 40°C
- must be suitable for positive pressure
- Suitable for temperatures up to 80°C
