Influence of Plants on the CO2 Concentration in the

Advanced Materials Research Vol. 1020 (2014) pp 524-528
© (2014) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMR.1020.524
Influence of Plants on the CO2 Concentration in the Passive
House
Sipkova Veronika1, a *, Galda Zdenek2,b, Labudek Jiri3,c, Hibler David4,d
1-4
VSB - Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba,
Czech Republic
a
b
c
d
[email protected], [email protected], [email protected], [email protected],
Keywords: Carbon dioxide, plants, passive house, microclimate
Abstract. The main point of this article is the analysis of the plants influence on the indoor
microclimate duality in the passive house, above all the influence on the CO2 concentration. The
measurements were made in the experimental passive house in the area of the Faculty of Civil
Engineering, VSB – Technical University of Ostrava in the spring months. The volumes of CO2
were analyzed during the many nights, in the room always with two men. In the first was made the
measurement without the plants and then during the next measurements were added plants into the
referential room which change the CO2 onto oxygen. During the separate measurements were
changed quantities of the green parts (of plants) where the photosynthesis change the CO2 onto O2.
In the second measurement was the blade area approximately equal to body area of the bigger
participant and in the third measurement was the blade area approximately equal to sum of the
bodies of both participants of the experiment.
Introduction
Currently, with modern buildings is much monitored healthy indoor climate. The legislation
directs the modern architecture of the buildings to the passive houses or to buildings with almost
zero energy, where is the quality of the breathing air adjusted using technological devices.
The results of the indoor microclimate quality were statistically evaluated (relative humidity,
indoor temperature, CO2 quantity) according to standard requirements. It is presupposed there is the
possibility to change indoor air quality in the dependence of the right selection of the home plants
and thus improve the home microclimate.
Measuring the influence of plants on the CO2 concentration in the passive house was done on an
experimental passive wooden houses – the professional training center of MSDK, which is located
in area of the Faculty of Civil Engineering, VSB – Technical University of Ostrava (the position
GPS: 49.845, 18.152). In this building, academics and doctoral students engaged in a number of
research projects have been published for example in [2], [3].
The building was completed in 2012, the use of layout dimensions and it is a family house in a
suburban area for four to five-member family.
The basic premise of energy-efficient buildings is controlled exchange of air between the interior
and exterior. For this is important good tightness of building envelope. The building in which the
measurements were carried, exhibits superior tightness of envelope constructions, which represent
space rate charging air n50 = 0.45 h-1. Therefore can be in the building to measure influence of plants
on microclimate.
Monitored parameters
High concentrations of CO2 can be very dangerous. Limit concentration according to [5] is
1200 ppm. Already when exceeding 1000 ppm may occur feeling sleepy and exhaled air, over
2000 ppm occurs less ability to concentrate and some people has even headache. Over 5000 ppm is
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Advanced Materials Research Vol. 1020
525
accelerating heartbeat. CO2 concentration exceeding 45 000 ppm lead to loss of consciousness and
death.
Relative humidity would ideally be from 30 % to 60 % and depends on the air parameters
supplied to the room and internal sources of within in the monitored area. Low humidity is harmful
because it burdens the airways and reduces immunity. Too high humidity combined with cold
surfaces is a common cause of condensation and mold formation on the surface structures.
The measurement procedure
Measurement of microclimate was conducted in the spring. In the long term were measured three
basic items inside buildings, which can be analyzed according to the microclimate. Was measured
air temperature θ [°C] and relative humidity φ [%] with heat-humidity sensor located in the center
of the measuring room at a height of 1700 mm. It is a temperature sensor Pt1000 and HC2-S RH / T
Rotronic. CO2 concentration [ppm] Siemens sensor placed in a wall with a slightly insufficient
extent (only 2000 ppm.). The values of these variables were recorded for three nights when in a
closed room without running air heating / ventilation slept two men. Order not to affect increasing
of the interior temperature (especially in the morning) building solar gains through windows [1], the
daily evening from 8.00 p.m. to 8.00 a.m. withdrawn exterior window shutters.
Plants were selected non-flowering with many green areas. Approximately first half of the plants
were C3 and second C4 [6]. All of them gain CO2 primarily through stomata on leaves and
secondary processes of photosynthesis incorporate it into organic molecules. The difference
between C3 and C4 plants is that the type 4 can be used as CO2 which is produced directly in the
plant in a process called respiration (breathing). The resulting - in fact waste - CO2 is excreted in the
area, but again engaged in the process of photosynthesis. C4 therefore consume far less CO2 than
C3.
Fig. 1: Used plants
The first night (from 3rd to 4th March 2014) in the room were no plants and the measured values
are used as comparative data to compare the following measurements nights with plants. Second
night (form 4th to 5th March 2014) was measured with plants, which had leaf area approximately in
the size of a body surface area of the greater participant of the measurement. Third night (form 5th to
6th March 2014) was measured with plants which had leaf area approximately in the size of a sum of
body surface area of both participants measurement.
Used plants were of different types, half of them should be C3 type and half C4. For measuring
was used for example Ficus Elastica Robusta, Ficus Elastica Tineke, Ficus Benjamina Wiandi,
Chlorophytum Comosum Epipremnum Pinnatum – Scindapsus, Hibricius Estele Kanzler and more.
All plants areas are in Table 1.
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Contemporary Problems in Architecture and Construction
Table 1: Areas plants in individual measurements
MEASUREMENT NUM.2
Average Average
Plants
Leaves
width
length
Area num.
num.
[pieces]
[m]
[m]
[m2]
1
0.140
0.040
120
0.448
1
2
0.300
0.045
18
0.243
2
3
0.350
0.020
27
0.189
3
4
0.320
0.010
73
0.234
4
5
0.200
0.100
6
0.120
5
6
0.170
0.080
38
0.345
6
7
0.110
0.060
73
0.482
2.060
SUMA
MEASUREMENT NUM.3
Average Average
Leaves
width
length
[pieces]
[m]
[m]
0.02
0.08
127
0.26
0.02
28
0.09
0.04
47
0.28
0.17
10
0.22
0.12
7
0.3
0.06
50
SUMA
Plants
Area
[m2]
0.203
0.146
0.169
0.476
0.185
0.900
2.079
The surface of the human body is 1.6 to 1.8 square meters depending on the height and weight of
a person. Content of the body surface can be approximately calculated according to formula (1) [4].
The surface areas of the bodies of both participants are evident from Table 2.
(1)
S = 167 ⋅ height ⋅ weight
Table 2: Areas bodies of both participants
Participant 1
Participant 2
Height [m] Weight [kg]
179
85
184
83
Body area [m2]
2.060
2.064
MEASURING 2
MEASURING 3
Fig. 2: Location of the plant at a room by measuring 2 and 3
Advanced Materials Research Vol. 1020
Graph 1: Concentration CO2 in the measuring room
Graph 2: The relative humidity in the measuring room
Graph 3: Temperature in interior and temperature gradient in the measuring room
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Contemporary Problems in Architecture and Construction
The measured values
Two men were in the room only at night. Measuring room was always thoroughly ventilated,
before the beginning of the measurement, but despite this during eight hours sleeping was measured
the concentration of CO2, which can be considered as hazardous to health [5]. After morning
leaving at approximately 7.30, the concentration of CO2 reached the level of 2000 ppm until after
14.00 at the first measurement and the second measurement at 17.00. For each measurement showed
no effect of plants on the concentration of CO2 (see Graph 1). CO2 concentration in all
measurements probably climbed high above 2000 ppm, but because of the range of the sensors is
not exactly how high.
In passive houses with hot air heating is generally a problem with low relative humidity. Graph 2
shows that two people can make equal the humidity around 40 % and together with plants, relative
humidity gets to the ideal 50 %. However this plant´s effect it is not only about the plants. Positively
contributes mainly to their watering, which is due to evaporation heat evaporates into the
surrounding environment.
The third graph (Graph 3) confirms the excellent insulation of building envelopes. Because the
interior temperature does not fluctuate significantly due to outdoor temperatures.
Summary
The measured values shown in graphs 1-3 tell us that plants have only a minimal impact on the
quality of the indoor environment from the perspective of CO2 concentration. Only what can be
achieved using plants is the modification of relative humidity due to evaporation of water vapor
from the individual pots.
Out of the measured data was confirmed that the family house in passive standard cannot work
with the windows closed without forced ventilation, which is caused due to the very low air
permeability of the building envelope. Users also complained of morning headaches, restless sleep
and an overall feeling of insomnia. All discomfort participants can have many causes among which
are undoubtedly high concentrations of CO2.
Acknowledgements
This post has been handled by the research Group of Building environment in project Creation of
scientific teams CZ.1.07/2.3.00 /20.0013.
References
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home energy consumption. Urban Ecosystems. 2012, no. 4. DOI: 10.1007/s11252-012-0246-3.
[3] Michnova, L., Martinik, L., Galda, Z., Sipkova, V., The assessment of the air-conditioning
function by PPD method, Indoor climate of buildings 2013 - proceedings, Strbske pleso 2013.
[4] Information on http://vnuf.cz/sbornik/prispevky/10-03-Trna.html
[5] CSN EN 13779. Ventilation for non-residential buildings: Performance requirements for
ventilation and room-conditioning systems. 2013. pub. Praha: CNI, 2013.
[6] Information on http://vydavatelstvi.vscht.cz/knihy/uid_es-002_v1/motor/main.obsah.html