PRODUCTS > ecoMaster Solutions > Passive Solar / Heat Recover Systems
The retrofit of the ecoMaster test home is almost complete.
The results have been nothing short of astounding. In a bid
to become a zero bill, zero emission (and highly comfortable!)
home, ecoMaster is now conducting a trial of two well known
passive solar heating systems, with a third due to be installed
shortly.
We will be conducting these trials on the ecoMaster test
home over the winter and monitor the results. The ecoMaster
test home will be open from time to time so you can see the
difference between the various systems. If you would like
to be part of an open day, please register your interest on
the web site. We will then advise you when the next open day
will be.
If you are looking at passive solar or heat recovery systems
in the meantime, here are a few questions to ponder….
What is the difference between passive solar and heat recovery
systems?
Passive solar heating systems use a solar collector to
generate heat and PV (solar) cells to generate power that
drives a ventilating fan. Heat recovery ventilation is a generic
term given to powered systems that recover heat from outgoing
air and transfer it to incoming air.
What are the different systems available?
The better known passive solar systems are
• Solar
Venti
• Sun
Lizard
• Smart
Breeze
The solar collector of the Solar Venti is a polycarbonate
fronted box that is fitted either to the roof or a wall. The
PV cell is within the box.
The Sun Lizard uses a glass fronted box that is fitted to
the roof. The PV cells are external to the box.
The Smart Breeze uses the corrugations of the corrugated
iron roofing as the solar collector. The PV cells are on the
box.
The best known heat recovery ventilator is the Venmar system.
Where does the air come from?
The Solar Venti draws its air from the back of the solar
collector. It is therefore a fresh air ventilator and passive
solar heater. The Sun Lizard draws air from within the home,
heats it and pumps it back into the home. The Smart Breeze
draws air from under the corrugations of the roofing iron.
This would normally be drawn up from the lower end of the
corrugations at the guttering level.
The Venmar draws air from within the home, transfers the
heat from the outgoing air to an equivalent of amount of fresh
incoming air and pumps that into the home.
Is air from your attic safe?
Ceiling insulation has evolved over a period of years
and there are many different forms ranging from non-toxic,
non-allergenic polyester, to glass fibre, rockwool mineral
fibre and even formaldehyde foam insulation (which has mostly
disintegrated into a fine powder). Glass fibre and rock wool
give off very tiny particles about the same size of those
as asbestos. Since 2000, glass fibre has been manufactured
to that those fibres are bio-soluable - that is, when they
lodge in your lungs, your body fluids gradually dissolve the
fibres away. Many homes were insulated before the advent of
bio-soluble fibres.
Systems that draw air from within the attic must have some
form of filtration. Whether the filtration system is able
to stop these particles from being pumped into your home is
an important risk factor to consider. You also need to consider
that the filters will need to be replaced regularly and what
costs, in money and time, are invovled.
Where is the heat delivered?
In the case of the passive solar heating systems the delivery
of the air is a function of the installation process. It is
highly desirable to have the heated air ducted out at floor
level. This maximizes the effective heating of your home.
Ducting the heat to ceiling vents is the most ineffective
heat delivery. As we all know - heat rises.
What ducting is used?
Given that the heat supplied by passive solar heating
devices and powered hybrid systems is modest when compared
with gas ducted heating, it is imperative that losses in the
ducting be minimized.
Until recently, the best insulated ducting had around 15mm
of polyester fibres in its outer skin. More recently, ducting
became available that has about 50mm of polyester insulation.
The better insulated the ducting, the less heat loss occurs
within the attic space, the more heat that is delivered within
the home.
Ceiling Registers
If you are considering a system that ducts through ceiling
vents you may wish to consider the following:
| • |
A well insulated ceiling in a temperate
area will have about R3.5 level of insulation cover. That
is between 150 and 180mm of bulk insulation. |
| • |
A 150mm (6 inch) duct 3 metres in length
adds almost 1 ½ square metres to the area to your
ceiling. |
| • |
This additional 1 ½ metres of ceiling
area is insulated to a far lesser extent than the rest
of the ceiling (see "What ducting is used?"
above). |
| • |
The effect is that winter heating naturally
drifts up into the ducting cools and comes back down into
the room. The ducting operates as a passive cooling device
of a winter's evening. |
Systems that are ducted to the floor level do not have this
problem.
Does my home need to be draughty?
Even the most effectively draught proofed homes leak air.
This is usually sufficient for systems such as the Solar Venti
and the Smart Breeze. Balanced systems such as the Sun Lizard
and the Venmar draw out the same amount of air as they pump
in.
Some powered hybrid systems use a high degree of ventilation
drawn from the attic and rely on the home being draughty in
order to provide an outgoing path for the ventilation. In
temperate, cool temperature and colder climates it is highly
undesirable to have a draughty home as this continuously facilitates
the loss of winter heating - particularly at night.
What does it cost to run?
Passive solar heating systems use the sun and solar powered
pumps which is free of cost and emissions.
What maintenance costs are involved?
There are no maintenance costs or running costs with passive
solar systems.
Powered systems usually require filter changes and obviously
use electrical energy. Green house gas emissions are dependent
on the selected energy source.
Powered systems usually require filter changes and obviously
use electrical energy. Green house gas emissions are dependent
on the selected energy source.
 Read what our clients have said about our services
Find out how we can help you
Call 1300 326 627 or email
ecoMaster
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