The normative references are 68 South African Bureau of Standards (SABS) that need to be considered.
In determining the assessment of water demand, according to SANS 10252-1:2004, the design population of the building shall be determined in accordance with regulation A21 of the National Building Regulations and Building Standards Act, 1977 (Act 103 of 1977).
For the assessment of the hot water demand, the following factors shall be considered:
One should differentiate between the peak and the design hot water demand so that the implications of an installation not meeting the peak demand can be recognised.
It should be noted that often the pattern of hot water usage is largely a function of the population and the type of activity that takes place in a building.
Table 2 and table 5 should be used to determine the hot water demand for the building. The usage should be tabulated on an hourly basis over the operating period of the building, in order to establish a pattern of hot water usage for the building.
There are numerous components to consider for a big project. Continuing with SANS 10252-1:2004 for the laws and guidelines, we take a look at the material that would be suitable for such conditions.
1. Materials, components, fittings and fixtures shall be selected that are suitable for the expected conditions of use.
2. If required, approval shall be obtained from the local authority regarding the use of specific materials or workmanship in the area concerned.
3. If it is desired or deemed necessary to use materials, components, fittings or fixtures not covered by this part of SANS 10252 or by an appropriate standard, proof of quality and performance of the material or workmanship shall be established by tests or by reference to other appropriate standards.
4. The following factors shall be considered when materials, components, fittings and fixtures are being selected:
a) life cycle costs
b) effect on water quality
c) intern al and external corrosion
d) compatibility of different materials
e) aging, fatigue and temperature effects
f) mechanical properties
g) durability
h) availability
i) water quality and
j) dezincification resistance.
5. All materials, components, fittings and fixtures in every part of a water installation shall
a) operate effectively under all normal conditions likely to be experienced when the water installation is in service, and
b) withstand, without damage or deterioration, sustained temperatures of
• up to 40°C in the case of cold water installations, and
• up to 60°C with occasional excursions up to 100°C in the case of hot water installations (in order to allow foe malfunctions of heated water fittings or components)
6. Selected fittings or components or any other apparatus shall not induce pressure surges that can cause damage to any part of the water installation.
7. Materials selected for the manufacture of purpose-made water heaters and storage containers shall be compatible with the quality of the water to be heated or to be stored, and shall comply with the relevant details given in the appropriate of pipes and pipes fittings.
8. When working with rubber, these are the factors that should be considered:
1. All rubber components that are in contact with potable water, such as joint rings, tap washers and flange packings, shall, in order to control the multiplication of Legionaella pnuemophila bacteria in water installations, be of a composition that will not promote microbiological growth.
2. Rubber joint rings that comply with the relevant requirements of SANS 974-1 and that have the dimensions, composition and hardness that are suitable for the particular application shall be deemed to be acceptable.
9. Thermal insulation material
The type and thickness of insulation material shall be suitable for the expected conditions of use.
1. in the absence of appropriate data, the thermal conductivity for the type of insulating material given
2. The use of dissimilar metals in the same below-ground installation should be avoided wherever practicable, or otherwise special measures shall be taken to prevent corrosion where pipes, pipe joints or connected fittings are of dissimilar metals.
