Sustainable Heating Systems
All buildings have energy loads, both within and on the structure.
To minimize these loads, the building can incorporate:
- Daylight - through the use of sufficient windows
to avoid the use of electric lighting during the day
- Passive cooling - Intelligent orientation to
take advantage of convection currents, cooling breezes and sunlight.
- Passive Solar Heating - to warm a building
in the winter; with due care to provide shade insummer and thereby
- Thermal mass stores - normalizing temperature
by storing heat during the day, releasing it at night. This can
be designed to heat the building in winter, and cool it in summer
- Insulation - well-insulated windows, doors,
and ceilings and walls to help reduce energy loss.
Every one of the above elements contributes to reducing energy
usage, without excessive construction cost or intrusion.
Heating and cooling systems account for a significant percentage
of energy used in buildings. An energy efficient home optimizes
heating and cooling systems that utilize either passive
solar heating or active
solar heating technology.
Passive heating is relatively inexpensive, any additional cost
being quickly recouped through energy savings. Active heating technologies
can be relatively expensive and can add significantly to the projects
cost. With a well integrated sustainable design concept, a building
can employ a combination of passive and active solar heating at
Substantial energy and financial savings can be gained from:
- Downsized heating, ventilation and air-conditioning (HVAC) equipment
- Hot water heat recycling is used to reduce
energy usage for domestic water heating.
- Ground source heat pumps are more energy efficient then other
forms of heating and cooling.
- Onsite generation of renewable energy from solar power, wind
power, hydro power, or biomass.
Cost of Sustainable Heating Systems
Onsite power generation is the most expensive feature to add to
a building. Other technologies can be incorporated at little addtional
cost. The cost of incorporating passive solar heating can be reduced
- The design of the building
- The materials used
- The use of passive solar elements
- External shading
- Thermal mass
- Good insulation
- Heat reclaim systems
- Night cooling - using cool night air to pre-cool the building’s
- Heat pumps - a very efficient way of transferring heat or cooling
from free air, water or ground to the building.
- Smart selection of high efficiency and variable speed fans and
Certain systems and materials that benefit the energy efficiency
of a home, have a dark side:
- Certain mechanical heating and cooling systems use refrigerants
- potent greenhouses gases damaging to the ozone layer. Only use
refrigerants with a zero Ozone Depletion Potential (ODP) and a
Global Warming Potential (GWP) of less than 10.
- Thermal insulation of pipe work and ducting must be CFC and
- Heating systems often use gas and electricity - which rely on
the use of fossil fuels, known to be in limited, exhaustible worldwide
Types of Sustainable Heating Systems
There are number of affordable, sustainable heating systems, including:
- Hot Water Heat Recycling / Drain Water Heat Recovery
- Solar Heating
- Wood Pellet Stoves
- Ground Source Heat Pumps (GSHP)
Hot Water Heat Recycling
Water typically enters the home between 5-12ºC. It is then
heated to 50ºC in the hot water tank, and mixed with cold water
to provide a shower head temperature of around 41ºC. Water
from the shower is then flushed down the drain at 37ºC.
Hot water heat recycling uses heat exchanger technology to recover
and reuse hot water heat from various activities such as dishwashing,
clothes washing and especially showers. The technology is used to
reduce primary energy consumption for domestic water heating while
also reducing greenhouse gases. Standard units save up to 60% of
the heat energy that is otherwise lost down the drain when using
Hot water heat recycling is also known as drain
water heat recovery, greywater heat recovery, and shower water heat
Drain Water Heat Recovery - works well in conjunction
with other types of water heaters, especially demand and solar water
Recycling this heat back into your homesubstantially reduces hot
water heating costs.
More on Sustainable
There are two types of solar panel heating systems, which are
based on different technologies.
- Solar Water Heating systems
[Solar Thermal Systems] uses the suns energy to heat water.
- Solar Photovoltaic or Solar PV systems generate electricity
- is an expensive technology, with a long payback period. Since
it also requires connection to an electrical system to boost power,
storage of power within this system is not yet fully developed.
In many countries, the heat from the sun is insufficient year
round to provide continuous power. For this reason, photovoltaic
systems must be combined with another power source, making the
entire energy supply set up prohibitively expensive for the average
More on Passive Solar
More on Active Solar
Wood Pellet Stoves
Wood Pellet stoves use softwood pellets typically made from manufactured
wood by-products, such as sawdust. Burning wood is not one of my
favorite heating forms, as the emissions frm chemically complex
non-softwood pellets is untested, and can potentially have environmental
and health hazards.
Ground Source Heat Pumps [GSHP]
Ground Source Heat Pump systems use a high-quality ground loop
and heat pump system to collect solar heat stored within the ground,
and convert it to energy. They then store this energy for future
use. These systems are currently expensive to install, and are not
able to supply the total heating energy needs of a home. Typcially
they provide only a maximum of 70% of the required heating energy.
The most acceptable sustainable heating system for an environmentally-friendly
home is generally a combination of the systems above. Many countries
provide grants or tax incentives, which help to offset some of the
Next: Active Solar
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