BS 6644:2005+A1:2008
$198.66
Specification for installation of gas-fired hot water boilers of rated inputs of between 70kW (net) and 1.8 MW (net) (2nd and 3rd family gases)
| Published By | Publication Date | Number of Pages |
| BSI | 2008 | 52 |
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | BRITISH STANDARD |
| 2 | Committees responsible for this British Standard |
| 3 | Contents |
| 5 | 1 Scope 2 Normative references |
| 7 | 3 Terms and definitions automatic natural draught burner non-automatic natural draught burner bank of boilers boiler house boiler room balanced compartment condensing boiler coefficient of discharge derated coefficient of discharge enclosure free-area |
| 8 | grille maximum allowable temperature maximum allowable pressure modular boiler modular system open-flue boiler operating pressure plant room room-sealed boiler safety temperature limiter safety valve |
| 9 | 4 Competence and design considerations 4.1 Competence 4.2 Design considerations |
| 10 | 5 Selection of boiler, materials and components 5.1 General |
| 11 | 5.2 Condensing boilers 5.3 Materials and components |
| 12 | 6 Installation 6.1 Siting of the boiler 6.2 Boiler rooms |
| 13 | 6.3 Equipment in the water circuit |
| 14 | Safety valve sizes (open vented systems only) |
| 16 | Cold feed pipe sizes Open vent pipe sizes |
| 19 | 6.4 Condensation in boilers 6.5 Gas supplies and pipework |
| 20 | 6.6 Electrical installation |
| 21 | 6.7 Boiler controls 6.8 Additional safety controls |
| 22 | 6.9 Air supply and ventilation |
| 23 | Minimum air vent free-area for room-sealed boilers installed in an enclosure |
| 25 | Mechanical ventilation flow rates |
| 26 | Typical balanced compartment ventilation location |
| 27 | 6.10 Flues |
| 30 | Siting of a natural draught flue terminal |
| 32 | 6.11 Boiler assembly |
| 33 | 6.12 Burner installation 7 Inspection, commissioning and servicing 7.1 General 7.2 Inspection 7.3 Commissioning |
| 34 | 7.4 Advice to be given to the user |
| 35 | 7.5 Maintenance |
| 36 | (Informative) Basis for the provision of combustion and cooling air to boiler houses and rooms in which commercial boilers are installed in accordance with this standard (Informative) Basis for the provision of combustion and cooling air to boiler houses and rooms in which commercial boilers are installed in accordance with this standard Introduction Data and assumptions The following assumptions were made in calculating the ventilation requirements specified in this standard. Boiler house temperature, as specified in 6.9.1.2: Fuel: Percentage of CO2 in the flue gases: Exit temperature of cooling air: Heat released into the boiler house: Speed of air through the ventilation openings: 2 m/sec. Specific heat of air: Volume of air required Combustion air Cooling air |
| 37 | Cooling air for a boiler not fitted with a draught diverter Cooling air for a boiler fitted with a draught diverter Ventilation requirements Natural ventilation |
| 38 | Natural ventilation for a boiler not fitted with a draught diverter Natural ventilation for a boiler fitted with a draught diverter Mechanical ventilation Mechanical ventilation |
| 39 | Mechanical ventilation flow rates |
| 40 | (Informative) Fan diluted flues (Informative) Fan diluted flues Fan diluted flue systems should be designed to reduce the CO2 concentration of the vented combustion products to 1 % (V/V) or less. Air for dilution should be ducted directly from the outside air. The emission velocity at the grille should be greater than 75/F m/s, where F is the fan dilution factor, defined as the final flue gas volume divided by the stoichiometric combustion volume. For typical UK natural gas F = 10, approximately. For typical The outlet grille should not be less than 50U/F m from any fan-assisted intake, other than combustion air or fan dilution air intakes, where U is the uncorrected chimney height (in m). The outlet should be at least 2 m above ground level for systems wit Uncorrected chimney heights The outlet should not be within 20U/F m of an openable window. The outlet should be at least 60U/F m away from adjacent buildings. The outlet grille should diffuse the products upwards, be so located as to minimize the re-circulation of combustion products and not be located under a canopy. The outlet grilles should not be sited in wholly enclosed wells or courtyards. |
| 41 | (Informative) Checks to be carried out on the boiler prior to commissioning (Informative) Checks to be carried out on the boiler prior to commissioning (Informative) Typical live run checks (Informative) Typical live run checks |
| 42 | (Normative) Combustion products analysis (Normative) Combustion products analysis Flue gas analysis shall be carried out in accordance with the manufacturer’s instructions. The following gives guidance on the procedure to be adopted. A suitable sample probe shall be inserted into the primary flue of the boiler (i.e. upstream of any draught diverter or draught stabiliser). Any port through which a probe is inserted shall be capable of being adequately sealed after use. It shall be ensured that there is sufficient heating load on the system to allow the boiler to be operated for the test period The boiler shall be adjusted to operate at the maximum nominal heat input stated by the manufacturer. If there is a suitably pla… The door(s) of the boiler house/room or balanced compartment or enclosure shall be closed. The boiler shall be operated at nominal heat input until stable conditions have been achieved before any measurements are taken. The carbon dioxide (CO2) [or oxygen (O2 )] and carbon monoxide (CO) concentrations in the flue gases shall be measured using equipment suitable for flue gas analysis, e.g. a gas analyser conforming to BS 7927. Where the carbon dioxide concentration has been measured, the “dry, air-free” percentage of carbon monoxide (CO) shall be calculated using the formula given by: |
| 43 | Concentrations of (CO2)N in Group H, P and B gases (percentage) |
