FEATURE
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mines where an entire shift comes to shower, the
domestic ones would typically be suited to a family
of at least three to be economically viable. Stiebel
Eltron’s heat pumps are premium products which are
meant to do more than supply domestic hot water
(DHW), but can do underfloor heating and cooling,
heat swimming pools and more.
The affordability of a centralised heat pump system
is affected by the number of units in a residential
block. Bosman says, “There are certain costs and
materials that have to be in the system, and the cost
of these gets averaged out, reducing the cost per
unit: if you go from an 80Kw to 160Kw system, it is
not double the price. During school holidays when
occupancy may drop to 50%, you still have all the
fixed costs to supply only half the water it should
and in that instance an alternative on-demand
system like instantaneous water heaters may be
more viable. On the other hand, with a solar water
heating system you have to either increase your
storage capacity or adapt your usage pattern in order
for it to be efficient, by, for instance, only showering
in the evening when the water is hot. With solar,
the standby losses, especially on RDP houses is
considerable, resulting in minimal hot water in the
morning, thus the electrical consumption remains
high due to the internal element being on to ensure
hot water by morning.”
The biggest downside of solar heating, he explains, is
that many buildings simply lack the space or facility
to install solar panels and it is consequently not
an option.
The plumbers’ role
SA Heat Pump Engineers imports four different types
of heat pumps from China, primarily at the larger,
commercial end of the market. Heat pumps need
regular maintenance – mainly cleaning. If one skimps
on maintenance one can expect poorer performance
and reduced life.
Some maintenance requires professional help –
but much of it one can do oneself. SA Heat Pump
Engineers director Godfrey Sutherland explains
that its installations come with a one-year warranty
during which it is responsible for maintenance which
is performed biannually, and thereafter moves to a
service level agreement contract. The complication
with servicing heat pumps is they cross over between
plumbing and refrigeration, requiring both expertise.
Plumbing skills are consequently not integral to such
servicing, he explains, as much of the skilled work
relates rather to refrigeration.
“In some instances, they do the maintenance inhouse
using our manual as the basis.” Properly maintained,
he says, a heat pump will have a life span much
longer than the repayment period.
“We supply our heat pumps to plumbers who install
them on site, and we provide them with the specialist
training they require for this,” says Anton van
Locherenberg of SA Heat Pump Engineers. “It is basic
plumbing skills to install an integrated heat pump, no
different to a standard geyser.”
March 2020 Volume 26 I Number 01
The rooftop evaporator at The Village, Bramley.
Sutherland says that while there is a steadily growing
volume of enquiries for heat pumps at the moment,
there are also more suppliers than ever in the market.
“In 2008/09 it was quite a niche market, but since
2015 there has been a marked increase in players
– more than the increase in demand.” Because the
demand is primarily coming from new developments
rather than replacement of installed geysers, demand
matches new residential developments, and SA Heat
Pumps finds there are a lot of old CBD buildings in
Johannesburg being refurbished. However, the new
development market has been affected by the demise
of several of the large construction companies over
the past two years.”
Sutherland says the maintenance of heat pumps
costs about R700 a service and R1 500 to R2 000
for a commercial unit, but in the case of residential
complexes the cost can be more than halved based
on economies of scale. PA
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