Installation and maintenance of flues and ventilation for gas appliances of rated input not exceeding 70 kW net (1st, 2nd and 3rd family gases) - Specification for installation and maintenance of ventilation for gas appliances
1 Equipment
This part of BS 5440 specifies the ventilation requirements for new or replacement gas appliances for domestic or non-domestic purposes utilizing 1 st, 2nd or 3rd family gases which carry the CE mark and with a rated heat input not exceeding 70 kW based on net CV (net calorific value). It may also be used for installations of appliances which are not required under the Gas Appliances (Safety) Regulations: 1995 [5] to carry the CE mark, e.g. used appliances. This standard does not cover:
a) LPG installations covered by the requirements of BS 5482-2 and installations with all gases covered by BS 5482-3;
b) any gas installations in caravans, holiday homes or residential park homes constructed to conform to BS EN 721 or BS 3632 as appropriate, which were installed at the time of construction;
c) decorative fuel effect gas appliances of the type covered by BS 5871-3.
NOTE 1 Standards that should be consulted are listed in normative references Clause 2 and the bibliography at the end of the standard.
NOTE 2 Maintenance requirements relating to existing vents are given in Clause 7.
NOTE 3 The installer should check the data given with an appliance to establish the basis on which the heat input is given. The data in this standard refers to heat input expressed in terms of net calorific values (CV) with conversion given for natural gas gross CV quoted in brackets where appropriate.
The ratio of gross:net heat input is approximately 1.11:1 for natural gas, 1.09:1 for propane and 1.08:1 for butane. For example, convert 9 kW input based on gross CV for natural gas to the equivalent net CV input as follows.
Net input = 9.0/1.11 = 8.1 kW.
The change to the method of quoting input rating is not intended to have any significant effect on the sizes of vents required for gas appliances as compared with the previous version of this standard (BS 5440-2:1989).
The differences in gross:net input ratio between natural gas, propane and butane are marginal and this factor has been taken into account when specifying the method of calculating vent requirements in 5.2.1.
2 Competence
It is essential that persons carrying out the installation of any gas appliance be competent to do so, and, in the case of any work that is subject to the current Gas Safety (Installation and Use) Regulations, it is essential to comply with these regulations.
It is essential that persons who design the ventilation system or installation have a knowledge and understanding of the standards and regulations that apply to ensure that the completed plans will produce a safe and satisfactory installation.
COMMENTARY AND RECOMMENDATIONS ON 1.2
At the time of publication, the body with HSE approval to operate and maintain a register of businesses who are "members of a class of persons" is the Council for Registered Gas Installers (CORGI). Thus it is essential that all business or self employed gas fitters should be registered with CORGI.
Guidance on the individual competency required for gas work is given in the Health and Safety Commission's Approved Code Of Practice (ACOP) —Standards of training in safe gas installation. [6]
Persons deemed competent to carry out gas work are those who hold a current certificate of competence in the type of activity to be conducted issued under the ACOP arrangements, or by a certification body accredited by the United Kingdom Accreditation Service (UKAS).