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DESIGN
TECHNICAL DATA
Hot and ColdWater System
Pipe Sizing / Materials
To achieve even distribution of the available supply of hot and cold water, it is
importantinanymainspressuresystem,thatthepipinginadwellingshouldbesized
in accordance with BS 6700.This is particularly important in a large property with
more than one bathroom.
However,thefollowingruleofthumbguidelinesshouldbeadequateformostsmaller
property types as long as water pressures are within the recommended range.
1. A 15mm copper or equivalent external service may be sufficient for a small 1
bathroom dwelling (depending upon the flow rate available),but the minimum
recommended size for new dwellings is 22mm (25mm MDPE).
2. The internal cold feed from the main incoming stop tap to the PulsaCoil A-Class
should be run in 22mm pipe. The cold main and hot draw-off should also be run
in 22mm as far as the branch to the bath tap.
3. The final branches to the hand basins and sinks should be in 10mm and to the
baths and showers in 15mm (1 metre minimum).
4. We would recommend that best results for a balanced system are achieved
by fitting appropriate flow regulators to each hot and cold outlet. This is
particularly relevant where the water pressures areabove therecommended
water pressure range. Details of suitable flow regulators are provided in
Appendix A.
Note: If manifolds (available as an optional extra) are being used suitable flow
regulators are automatically provided in the manifold and do not need to be
provided at each outlet.See Appendix B for further details.
Alltherecommendationswithregardtopipeworksystemsinthismanualaregenerally
based on the use of BS/EN Standard copper pipework and fittings.
However,wearehappythatplasticpipeworksystemscanbeusedin placeofcopper
internally as long as the chosen system is recommended for use on domestic hot
andcoldwatersystems bythe manufacturerandisinstalledfully inaccordance with
their recommendations.
Thisisparticularlyimportantinrelationtouseofpushfitconnectionswhenusingthe
optional flexible hose kits - see installation section of this manual.
It is also essential that if an alternative pipework material/system is chosen the
manufacturerconfirmsthatthedesigncriteriaofthenewsystemisatleastequivalent
to the use of BS/EN Standard copper pipework and fittings.
Taps/Shower Fittings
Aerated taps are recommended to prevent splashing.
Any type of shower mixing valve can be used as long as both the hot and cold
supplies are mains fed. However all mains pressure systems are subject to
dynamicchangesparticularlywhenotherhotandcoldtaps/showersareopened
and closed,which will cause changes in the water temperature at mixed water
outlets such as showers. For this reason and because these are now no more
expensivethanamanualshowerwestronglyrecommendtheuseofthermostatic
showers with this appliance.
The shower head provided must also be suitable for mains pressure supplies.
However,if it is proposed to use a‘whole body’or similar shower with a number of
high flow/pressure outlets please discuss with the Gledhill technical department.
The hot water supply to a shower-mixing
valveshould be fedwhereverpracticaldirectly
from the PulsaCoil A-CLASS or be the first draw-
off point on the hot circuit. The cold supply
to a shower-mixing valve should wherever
practical be fed directly from the rising mains
via an independent branch. The shower must
incorporateorbefittedwiththenecessarycheck
valvestoprovideback-syphonageprotectionin
accordance with theWater Regulations.
Thesupplyofhotandcoldmainswaterdirectly
toabidet ispermittedprovidedthatit isofthe
over-rimflushingtypeandthatatype‘A’airgap
is incorporated.
Hot and ColdWater System
Ifthelengthofthehotwaterdrawoffpipework
is excessive and the delivery time will be more
than 60 seconds before hot water is available
atthetap,youmaywishtoconsiderusingtrace
heating to the hot water pipework such as the
RaychemHWATsystem. PleaseconsultGledhill
Technical Department for further details.
Note: A conventional pumped secondary
circulation system is NOT suitable for use with
this appliance.
It is important that the cold water pipework
is adequately separated/protected from any
heating/hot water pipework to ensure that
the water remains cold and of drinking water
quality.
