PROJECT
<< Continued from page 41
43
Twelve Alpine easy flat plate collectors are installed in
two arrays of six. The solar pump transfers energy from
these panels to the domestic tanks and is then diverted
to the hot water buffer if the tanks are on temperature.
This is topped up with high-temperature water from
the solar collectors. To provide for when the climatic
conditions do not suit the solar, or when the water
demand in the lodge is extremely high, a 32kW Fondital
Itaca condensing modulating gas boiler has been
installed on the top coil of the tank. This will ensure that
the lodge never runs out of hot water.
1
The domestic hot water is critical for the lodge. There
are 2 000 litres of storage with Boiler Nova high-
pressure tanks. Domestic water is heated primarily with
a transfer pump on the coil of the domestic tanks from
the hot water buffer tank. This achieves a temperature
of around 52°C.
to heat exchangers in the pool circulation loops. Pools
can be actively heated with energy from the heat pump
when in heating mode or alternatively from rejected
heat in cooling mode. This ensures that in cooling
mode, waste rejected heat energy is rejected to the
pools before the geothermal loops-field. There are also
dedicated Lovato high-temperature group-sets for the
heated towel rails.
2
Terminals
All heating and cooling terminal units, underfloor, and
domestic water are reticulated in an underground
insulated trench that runs in the centre of the lodge.
The underfloor system generates most of the heat
required in the spaces. Underfloor cooling provides
additional comfort during scorching summer months and
is carefully controlled via a hygrostat and mixing station
to prevent condensation from forming on the floors if the
temperature drops below dew point.
3
The swimming pools each have a Bowman stainless-
steel shell and tube heat exchanger to provide the energy
required to maintain the swimming pools at 28°C all year
round, even though the pools have an overflow that acts
as a ‘cooling tower’ and therefore requires a larger than
usual amount of energy.
The heated towel rails, which only operate in a heating
mode, are supplied with water that does not allow the
temperature to burn the skin, but only heats up the
towels and space to a comfortable temperature.
EQUIPMENT SELECTION
The true beauty of the system installed at Kubili is the
integration of the various services into a cohesive,
www.plumbingafrica.co.za
sophisticated plant that runs efficiently and meets all the
client’s needs. That is why it was crucial that everyone
worked closely together on the design so that everything,
from the domestic hot water to the FCUs, all ties in
seamlessly and no energy is wasted.
An Aermec heat pump-chiller was installed in the
plant room. This is a low noise; high-efficiency unit
with a dual refrigerant circuit, electronic expansion
valves, and onboard high-pressure circulator pumps
for the heating and cooling circuits. The domestic
hot water system is backed up by a 32kW Fondital
Itaca gas-fired direct boiler of the condensing,
modulating type.
1.
2.
3.
Conductivity test with test
unit in progress.
Geothermal system layout.
During a recent site
visit… the project team
and guests, front from
left: Dennis Holden, Nino
Agostinelli, and Ryan
Scholtz. Back, from left:
Henri van Niekerk, Ben
Hefer, Albertus Lombaard,
George Thomaides, Tinus
Venter, Christiaan Delport,
Mike Nel, Chris Elliot, and
Mario de Freitis.
Continued on page 45 >>
July 2018 Volume 24 I Number 5