Biological air cleaning system (BACESS)
In 1989 after nearly 20 years research NASA published that the superior
air purification was carried out by a system consisting of plants and
soil. The root zone system BioVentic is an air treatment system based
on light soil filter with vegetation. Contaminated air is
pressed through the root zone filter by a ventilator. Energy
consumption is 38
watt/h. Installation has been set up in Denmark, Sweden, Netherlands,
USA and since 2007 in Greenland.
This study has been made with a view
to objectifying root zones possible cleaning efficiency in slightly
different setups measuring selected parameters which normally are used
when examining indoor climate. While NASA has been working with tests
under strictly controlled conditions, this present study was on
practical plants in operation. The study has shown that especially soil
covered with limestone has the largest cleaning efficiency and does not
give unintended side effects. Based on the present tests root zone
installations seem to be effective and they can certainly strengthen
the indoor climate to a great extent.
on the chart for an increasing view.
The invention is based on the knowledge that soil, which contains
microorganisms and serves as a substrate for plants, has a capacity to
remove harmful particles and gases from the air.
Measurements on installations have shown the following results:
- Health and comfort condition based on questionnaires
Glostrup Hospital, Denmark showed that health and comfort problems are
in average reduced by 50%.
- Temperature is reduced due to high evapotranspiration
the soil media and the plants. The temperature reduction is
approximately 3 °C in the range of 2 – 5 °C.
reduces the relative humidity and evaporation helps raising the
- PM10* was significant reduced
2-29% in Post-Denmark
office and 15% in Transform office comparing with and without air
- At bank office
(Copenhagen, Denmark) it was observed that the installation could clean
for PM10 relative to the external reference approxemately 75%, and
relative to the internal reference at
* PM10: Particulate matter up to 10 micrometers
particles between 2.5 and 10 micrometers in smoke, dust and dirt from
factories, roads and farming, as well as mould spores and pollen.
- Chemical reductions tested in climate chambers
University, Denmark) resulted in an efficiency of 90% when comparing
with and without air treatment.
- 22 smell based chemicals are tested between intake
outlet with cleaning efficiency 80-99% for the chosen chemicals and
25-71% for ammonia.
- Bacteria were reduced with 81-95% when comparing
values between intake and discharge from the root zone.
- Micro fungi in the air were reduced by 89% when the
was covered with limestone. However the same test, without limestone,
increased the emission of micro fungi by a factor of 3.
- Efficiency based on number of fungal
showed a 81% reduction after passing through root zone covered
limestone. However yeast cells from plants can be released and raise
concentration nearby the vegetation.
Suitable plant genera are for example:
- Chrysanthemum morifolium
- Dracaena deremensis
- Philodendrum domesticum
- Chlorophytum comosum
- Epipremnum aureum
- Schefflera ssp.
- Sansevieria ssp.
- Spathiphyllum ssp.
among other possible species.
New improved design
Principle root zone
Technical layout: Air ventilation per hour should be 50% of the room
Søren Thorhauge Andersen
Bacess A/S and Transform
af 1994 ApS
9260 Gistrup, Denmark
Patent: EU 1356239, ZL 01822087.8 (China), 6,638,338 B2 (USA)
This is an altered
version by Michael Blumberg, by courtesy of the authors.
The main text you will find here:
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