Standards Development

Scope

This part of BS 5440 specifies the requirements for the installation and maintenance of ventilation provision relating to gas appliances utilizing 1st, 2nd or 3rd family gases, with a rated heat input not exceeding 70 kW based on net CV (net calorific value), used for domestic or non-domestic purposes.

This standard does not cover:

a) liquefied petroleum gas (LPG) installations covered by BS 5482-2 and installations with gases covered by PD 5482-3;

b) gas installations in caravans, holiday homes or residential park homes conforming to BS EN 721 or BS 3632 as appropriate, which were installed at the time of construction;

c) decorative fuel effect gas appliances, covered by BS 5871-3; or

d) multiple cooking appliance installations in catering establishments and schools.

NOTE 1 Although this part of BS 5440 has been developed mainly for use with gas appliances that carry the CE mark, it may also be used for installations of gas appliances which are not required under the Gas Appliances (Safety) Regulations [1] to carry the CE mark, such as used appliances.

NOTE 2 Maintenance requirements relating to existing vents are specified in Clause 8.

NOTE 3 It is essential that the installer checks the data given with an appliance to establish the basis on which the heat input is given. The data in this standard refer to heat input expressed in terms of net CV with conversion given for natural gas gross CV quoted in brackets, where appropriate.

NOTE 4 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, 9 kW input based on gross CV for natural gas is converted to the equivalent net CV input as follows: Net input = 9.0/1.11 = 8.1 kW.

NOTE 5 For requirements for the installation and maintenance of gas fired catering appliances for use in all types of catering establishments (2nd and 3rd family gases), see BS 6173. Further information regarding volume air flow rates in the catering environment can be found in DW 172, Specification for kitchen ventilation systems [2], and CAIS 23, Gas safety in catering and hospitality [3].

Purpose

A revision is needed to ensure the industry is up to date with the use of different flue types, specifically for C-type appliances, the changes within Part F of the Building Regulations with regards to ventilation, the reinforcement of the requirements of Part J of the Building Regulations for flues in voids and the assurance around new build properties with lower levels of air permeability.

The input of the Gas Safe technical bulletins that have been published over the past 14 years, as well as the removal of design and build of shared flue systems that are no longer being built, such as U-Ducts, Se-Ducts, and Shunt-Ducts to make the Standard must easier to follow. The strengthening around internal kitchens is in dire need of expanding on within the document to help clarify the requirements of combustion air vs purge air. The document is now 14 years out of date, surpassing its 5 yearly review requirements by 9 years. There are multiple areas that need reviewing and strengthening around flue installations to help strengthen the manufacturer’s instructions and also help create consistency.