Glow-worm Ultrapower sxi Range - Manual (Page 15)

15
5 Domestic Hot Water
5.5 SYSTEM REQUIREMENTS – Domestic Hot
Water
Domestic Hot Water Requirements
NOTE: Attention is drawn to the following extracts from the
Building Regulations 1991.
Regulation 11(1) (Giving of a building notice or deposit of
plans)
“Subject to the following provisions of this regulation, a person
who intends to carry out building work or to make a material
change of use shall:
a) Give to the local authority* a building notice in accordance
with 12; or
b) Deposit full plans with the local authority* In accordance
with regulation 13”.
Regulation 12(4) (Particulars and plans where a building
notice is given)
“………a building notice shall be accompanied by a statement
which specifies:
*Attention is drawn to regulation 18 (supervision of building
work otherwise than by local authorities).
a) The name, make, model and type of hot water storage
system to be installed;
b) The name of the body, if any, which has approved or
certified that the system is capable of performing in a
way which satisfies the requirements of paragraph G3 of
Schedule 1;
c) The name of the body, if any, which has issued any
current registered operative identity card to the installer or
proposed installer of system.”
Regulation 13(3) (Full plans)
“Full plans shall consist of:
a) Description of the proposed building work or material
change of use, and the plans, particulars and statements
required by paragraphs (1) to (4) of regulation 12: and
…….”
NOTE:
Bye-laws of the appropriate Water Undertake also apply.
Discharge Pipework
It is a requirement of Building Regulation G3 that any
discharge from an unvented system is conveyed to where it
is visible but will not cause danger to persons in or about the
building. The tundish and discharge pipes should be fitted in
accordance with requirements and guidance notes of Building
Regulation G3. The G3 Requirements and Guidance section
3.9 are reproduced in the following sections. Information
Sheet No. 33 available from the British Board of agreement
gives further advice on discharge pipe installation. For
discharge pipe arrangements not covered by G3 Guidance or
BBA info sheet no. 33 advice should be sought from your local
Building Control Officer.
G3 Requirement
“….there shall be precautions….. to ensure that the hot water
discharged from safety devices is safely conveyed to where it
is visible but will not cause danger to persons in or about the
building”.
G3 Guidance SECTION 3.9
The discharge pipe (D1)from the vessel up to and including
the tundish is generally supplied by the manufacturer of the
hot water storage system. Where otherwise, the installation
should include the discharge pipe(s) (D1) from the safety
device(s). In either case the tundish should be vertical,
located in the same space as the unvented hot water storage
system and be fitted as close as possible and within 500mm
of the safety device e.g. the temperature relief valve.
NOTE: The tundishes are factory fitted during manufacture.
The discharge pipe (D2) from the tundish should terminate in
a safe place where there is no risk to persons in the vicinity of
the discharge, preferably be of metal and:
a) Be at least one pipe size larger than the nominal outlet
size of the safety device unless its total equivalent hydraulic
resistance exceeds that of straight pipe 9m long i.e. discharge
pipes between 9m and 18m equivalent resistance length
should be at least two sizes larger than the nominal outlet
size of the safety device, between 18 and 27m at least 3
sizes larger and so on. Bends must be taken into account in
calculating the flow resistance.
An alternative approach for sizing discharger pipes would be
to follow BS67100:1987 specification for design installation,
testing and maintenance of services supplying water for
domestic use within buildings and their curtilages. Appendix E
section E2 and table 21.
b) Have a vertical section of at least 300mm long, below the
tundish before any elbows or bends in the pipework.
c) Be installed with a continuous fall.
d) Have discharges visible at both the tundish and the
final point of discharge but where this is not possible or is
practically difficult there should be clear visibility at one or
other of these locations. Examples of acceptable discharge
arrangements are:
i) Ideally below a fixed grating and above the water seal in a
trapped gully.
ii) Downward discharges at low level; i.e. up to 100mm above
external surfaces such as car parks, hard standings, grassed
areas etc. are acceptable providing that where children may
play or otherwise come into contact with discharges a wire
cage or similar guard is positioned to prevent contact whilst
maintaining visibility.
iiI) Discharges at high level; e.g. into a metal hopper and
metal down pipe with the end of the discharge pipe clearly
visible (tundish visible or not) or onto a roof capable of
withstanding high temperature discharges of water and 3m
from any plastic guttering system that would collect such
discharges (tundish visible).
iv) Where a single pipe serves a number of discharges,
such as in blocks of flats, the number served should be
limited to not more than 6 systems so that any installation
discharging can be traced reasonably easily. The single
common discharge pipe should be at least one pipe size
larger than the largest individual discharge pipe (D2) to
be connected. If unvented hot water storage systems are
installed where discharges from safety devices may not be
apparent i.e. in dwellings occupied by blind, infirm or disabled
people, consideration should be given to the installation of an
electronically operated device to warn when discharge takes
place.