Solartwin
Innovative 100% solar
pumped solar hot water systems for washing & bathing
Third
generation specification.
A standard
Solartwin installation supersedes traditional solar in several ways. It gives
direct solar water heating from a patented, freeze tolerant, double-glazed flat
plate with a variable low speed photovoltaic circulation, using no heat
exchanger. (Earlier
solar generations used indirect antifreeze circuits, heat exchangers, mains
powered control, high speed pumping plus single or double glazed collectors such
as metal back-piped flat plates or partial-vacuum tubes.)
How
big is the panel?
It
usually looks big on the ground and smaller on the roof! The
main Solartwin water heating panel measures 2.5m x 1.3m x 75mm deep. (8’
6” x 4’ 6” x 3”) high. Fitted, it normally projects less than 100mm
above the roof, so it is often treated as “permitted development” by UK
planners. (Under 79mm projection is usually possible.) Its “footprint” with
frame is 3.25 sq m. The “aperture” to the sun is 2.8 sq m. Lightweight,
weighing 31 kg (empty) or 33 kg (full) it rarely requires UK building control.
What is
it made of?
The main metal is
mainly hydroelectrically made aluminum, with a lower environmental impact than aluminum
made using fossil fuel. For
durability, external screws / bolts are stainless steel. The absorber coatings
are semi selective. Double glazing is UV-stable polycarbonate. Double, rather
than single glazing optimizes
winter performance. Insulation is zero-ODP pentane-blown rigid
foam.
And the
pump?
The
21-volt (peak) photovoltaic panel powers a self-regulating,
variable
speed, long life brush less
DC motor.
This
drives Solartwin’s positive displacement pump. Valves in it stop “reverse
thermosyphon” at night, and a bypass valve protects against “frozen by day”
conditions.
Flexible
pipes.
Solartwin’s
freeze-tolerant, corrosion-resistant pipes are made of silicone rubber. Its
extreme temperature tolerance range is: -60C to +200C! This silicone is also
used, for hygiene reasons, for milk pipes in dairies. Its material conforms to
the requirements of UK-WRAS for hot water and European Extraction Testing Regs
90/129/EC (BGVV XXI) for food contact, and USA FDA 21 CFR 177.2600 for food
contact.
How big
is Solartwin’s output?
Solartwin typically
heats a normal 120-litre cylinder to 50-60C on a sunny March or Sept. day
(60-80C in summer). Independently
tested, Solartwin delivered 1000 kWh (3.6 GJ) of energy as hot water a year in
UK. It saves far more bought-in energy. Peak output is 1.6 kW, similar to an
immersion heater.
Yes,
Solartwin cuts global
warming!
