TECHNICAL
51
TECHNICAL
51
B-rated
water heaters
Edited by
Eamonn Ryan
The following is a Tech Talk presented by
Adriaan Myburgh on B-rated geysers – a term that
has been abused or misinterpreted.
It is a legal requirement in terms of VC
9006 that all geysers must have an energy
efficiency rating of at least class B. It is
also a requirement in terms of VC 9006
that all geysers must have a LOA issued
by NRCS.
Only some geyser suppliers currently offer
geysers that comply with the class B requirement
and/or a LOA. A sales permit may be issued by
the NRCS. In layman’s terms a sales permit can
be regarded as a LOA.
6.6 Standing loss
6.6.1 Standard and heat pump water heaters
The standing loss per 24 hours, determined
in accordance with 7.4.3 shall not exceed the
values given in columns 2, 3 or 4 (as relevant)
of table 3, appropriate to the nominal capacity
of the water container given in column 1, or
the value marked on the water heater (see
8.1.1 (e)) whichever is the lower, or obtained by
interpolating between the two values on either
side of the marked rate capacity.
6.6.2 Solar (without solar collector) water heater
The standing loss per 24 hours, determined in
accordance with 7.4.3 shall not exceed 75% of
the value given in column 2, 3 or 4 of Table 3 (or
obtained by interpolating between the two values
on either side) of the marked capacity of the
water container in column 1 or the valuer marked
on the water heater (see 8.1.1 (e)).
Should the installation be regarded as compliant
if a geyser without class (without NRCS or a sales
permit) is installed? What documentary evidence
should be provided to the auditor or inspector
to verify the validity? The most important
documentation is the SANS 151 – the standard
that geysers get tested – to be awarded the Mark
or to be listed as complying.
SANS 151
March 2020 Volume 26 I Number 01
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