PROJECT
29
“The system is as much an HVAC as a plumbing system, and
compliance to standards is consequently challenging. There
simply are no plumbing standards other than for domestic heat
pumps. The piping, valves and electrical systems are compliant
to standards with PIRB and SANS. Electrical CoCs are also
a requirement. Installation of such a system consequently
requires a team of plumbing, HVAC and electrical technicians,
which are all inhouse at EESCO.
“The system typically requires three services a year, of
which two are simply a visual inspection, cleaning of the
evaporator coils and checking for refrigerant or oil leaks.
The third is more detailed with among others, the liquid line
driers replaced, oil condition evaluated, strainers cleaned,
and electrical service. When it comes to evaporator coils,
they can be custom designed for each site. There is a
choice of vertical air discharge – flat bed or V-coil and
horizontal discharge. In this case we designed them to fit
existing louvres in the walls (to expel the cold air), and we
decided to go with hanging, horizontal discharge types.
We have also used different heating mediums for our
evaporators – the norm is to use the typical Air-Water type
evaporators – we have successfully used water-refrigerant
evaporators. These ‘shell-in-tube’ type evaporators can be
installed anywhere as they do not require any airflow,” says
Thomas.
Water ring main system, plumbing, drainage
and sanitaryware
This R9-million contract to reticulate hot and cold water from
the plant room to the 404 units up to the eighth floor, as well
as all the plumbing, drainage and sanitaryware, was allocated
to Pretoria-based Plumbcon Construction Plumbing. Director
Francois Dreyer explains that the firm was responsible for the
complete plumbing installation: water piping, sewer drainage
and sanitaryware installation.
plumbing project. The challenge, as with all projects, was the
time frame.”
A ring main system is achieved by the installation of a
circulating pump on the end of the flow line close to the
hot water cylinder. The hot water is thus drawn around the
ring type main and re-enters the hot water cylinder by way
of the cold feed. The ring main is passed close by fittings
requiring instant hot water and a pipe as short as possible
is connected from the fitting to the ring main. It is this short
distance that reduces the time it takes for hot water to reach
the fitting. PA
Supplier list:
Heat pump design
EESCO
Heat pump manufacture SCM (Cape Town)
Fibreglass tanks
Heat exchangers
Compressors and
Variable Speed Drives
Evaporator coils
Plumbing company
Sanitaryware
Piping
Construction company
Solar Heat Exchangers and IEES (Integrated Energy and
Environmental Solutions)
Alfa Laval (France) and Onda (Italy)
Danfoss (Germany)
HC Heating Exchangers (Johannesburg) and Colcab (Cape Town),
RefriComp
Plumbcon Construction Plumbing
Italtile
Henco (Belgium)
Naumann Construction (Cape Town)
With residential developments of this size, it becomes
necessary to achieve almost instant hot water at the tap and
so it is a good idea to install a main hot water supply pipe with
a return pipe to the hot water cylinder and circulate the hot
water around this pipe. All hot water piping is lagged with pipe
insulation to minimise the heat loss.
“Our brief was to run the water supply in the soffit of the
ground floor, rising to the units and to return the water supply
back to the plant room. We also installed the sleeves and some
of the waste piping system in the superstructure. The crimp
piping was by Henco at the specification of the company’s
internal wet services engineer – it was a design and supply
Three 10 000l low pressure thermal storage vessels – these act as a ‘battery’ storage
for when hot water demand is high.
September 2020 Volume 26 I Number 07
www.plumbingafrica.co.za