SA Affordable Housing September - October 2019 // ISSUE: 78 | Page 27

FEATURE
ENERGY EFFICIENCY
The pumps require regular service in the same manner as
does a car: without it, the COP will steadily worsen and the
system ultimately fail – again, like a car. A basic service
requires descaling of the heat exchanger, cleaning out the
condenser to ensure no build-up of residue and checking the
condition of the heat pump’s components, levels of gas and
inspecting the pipe insulation.
Van den Berg attributes heat pumps not being more
commonplace, to the same sort of negative perceptions as
bedevilled solar heaters before it: substandard products were
imported and often shoddily installed by unqualified crews,
resulting in defective performance and disillusion.
“Stiebel Eltron has more than 40 years of experience with
heat pump installation all over the world. We´re one of the
market leaders in that segment and are trying with technical
training and efficiency demonstration to prove that a
heat pump is the best and most efficient way to produce
domestic hot water. A heat pump is a complex system and
there are many faults that can occur during the installation,”
says Altmann.
“The benefit, of course, is that households will have a
working and efficient system, that saves them more than 60%
of the cost for domestic hot water heating,” says Altmann.
PAYBACK TIME
James Vermeulen, Electrolux product manager: Green Energy.
will still have an energy efficient solution for his domestic
hot water production. Instantaneous water heaters have no
standby losses and waste a minimum of water, as the pipe
distances are short.
“The big benefit of an instantaneous water heater is that it
is installed close to the point of use, and so it can save water
and electricity. You don´t have long pipe distances and you´ll
have hot water immediately. The units consume electricity
only when working and hot water is needed. You´ll have
no stand-by losses, which will save the tenant or owner
approximately 35-40% of his electricity bill, compared to a
standard geyser. Furthermore, an instantaneous water heater
will save a lot of space. Especially in the affordable housing
segment, where space is often an issue, which is an important
benefit to the tenant,” explains Altmann.
WHAT ARE THE MARKET BARRIERS FOR
RENEWABLE ENERGY SOLUTIONS?
Altmann suggests that one big market barrier to more
widespread deployment of renewable solutions is the higher
initial investment that people have to make for a heat pump
or solar system compared to a standard geyser system.
“But,” he adds, “the return on investment is very quick, and
afterwards the owner will save a lot on his running cost.”
The payback time for a heat pump compared to alternatives
is highly variable, as it depends on hot water usage, ambient
air temperature and the COP of the actual device. A heat
pump is only as good as its installation: Pipe distances must
be kept as short as possible; and the pipework needs proper
insulation to avoid energy losses. All this influences the
performance of a heat pump and the efficiency you can get
out of the system.
Altmann says, “Of course the payback time for heat
pumps is dependent on many influencing factors, like hot
water consumption. To give you an example, for a standard
three-person household with showers, bathtub, kitchen-
and handwash sink, the amortisation will be within 4-5
years. The savings that you can create in such a case with a
heat pump, can be up to R70 000 within a 10-year period.”
To calculate the estimated return of investment for your
specific application, Stiebel Eltron offers a tool, which you
can download online, at: https://www.stiebel-eltron.co.za/
toolbox/tools/?excel.
Advancements in technology are being made all the
time, but the pricing has not reduced due to the impact
of the exchange rate. In hard currency terms, says James
Vermeulen, Electrolux product manager: Green Energy, the
price has come down to the extent that prices have not
increased in recent years even as the exchange rate has
considerably worsened. “For the same amount of money,
today you get a lot more advanced technology than what
you would have had in 2010, when Kwikot first started
importing heat pumps. For instance, heat pumps that
heated water to 55°C now heat it to 75°C, the same as what
you would achieve with a resistance element – for a third of
the energy.”
"Innovative water heaters are negating the need for
traditional energy-guzzling geysers, which account for 60% of
a home’s electricity bill."
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SEPTEMBER-OCTOBER 2019
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