i-zeb project towards intelligent zero energy buildings
Redevelopment experimental building Zeb - Vertical Garden - Sundar Italia
Collaboration Framework Agreement between the Lombardy Region and the National Research Council (CNR)
THE PROJECT
I-ZEB "Towards Intelligent Zero Energy Buildings" has led to the creation of a full-scale ZEB laboratory for energy-environmental analyses aimed at assessing the performance of building envelope and system components in real conditions. The monitoring system installed has allowed the continuous acquisition of data for the verification and optimization of performance, in order to reduce consumption, improve air quality and overall comfort.
The environment was used as an office with the installation of two workstations each equipped with a desk, chair and computer, one near the "Living Wall Sundar" (from now on "Sundar Vertical Garden") and one near the access door to the laboratory.
The trial lasted 12 months.
THE VERTICAL GARDEN
Inside the ZEB laboratory an internal Sundar Vertical Garden of about 10 square meters of total surface has been installed on an internal partition positioned between room A1 and room A3, as shown in the figure.
OBJECTIVES
To highlight the potential of the Sundar Vertical Garden in maintaining and improving adequate levels of indoor air quality .
Identify which are the construction and size parameters of the Sundar Vertical Garden suitable for a proper design so that it not only plays a mitigating action, but can enter fully into the design of the system and optimize the management settings.
RESULTS
The experimentation, which lasted about a year, led to the conclusion that the presence of an appropriately sized Sundar Vertical Garden can generate benefits
In terms of air quality
In acoustic terms
In terms of global comfort
COMPARISON WITH LEGAL REQUIREMENTS
The installation of the Sundar Vertical Garden has improved the acoustic insulation of the partition wall and this has made it possible to meet the legal requirements of acoustic insulation of partitions between different building units, established by the Prime Ministerial Decree of 05/12/1997. This requirement sets a limit, for office environments, of R'w ≥ 50 dB.
The presence of the Sundar Vertical Garden has improved the sound absorption in the environment in which it was installed, allowing to respect the optimal reverberation time for offices, defined by the Italian technical standard UNI 11532.
ANALYSIS OF INDOOR ENVIRONMENTAL COMFORT
Indoor Air Quality (IAQ)
This term is used to define the quality of the air inside and around buildings by measuring comfort and healthiness in relation to the occupants. In almost all cases, on a daily average, the indoor environment is always more polluted than the outside, adding to the pollutants already present in the outside air further elements generated inside.
Search settings
On each of the two workstations set up, two monitoring points were set up with four sensors for monitoring relative humidity and indoor temperature, for measuring air speed and illuminance level. The experimental environment was also equipped with other measuring points for monitoring the operating air temperature, the radiant temperature and the relative humidity of the indoor environment, as well as the concentration of CO2 and VOCs.
RESULTS
It has been observed that the presence of the Sundar Vertical Garden reduces the concentration of CO2. A necessary requirement for this to happen is the utmost attention to the correct sizing of irrigation, which avoids damaging the plants and increasing humidity.
In the absence of air exchange with a worsening air quality, the presence of Sundar Vertical Garden gives a better perception of air quality. With the same environmental conditions between the two locations, the only difference is the proximity of the Sundar Vertical Garden which is a positive presence synonymous with air quality.
It was shown that in a properly controlled environment the perception of air quality depends not only on environmental parameters but also on biophilic aspects such as the presence of a Sundar Vertical Garden.
SOUND ABSORPTIONANALYSIS
Comparing the results of the three different samples, it is evident that there is a significant improvement in noise absorption, especially at medium and high frequencies, due to the plants in the Sundar Vertical Garden; in particular, the small-leaved plants perform better than the large ones.
ANALYSIS OF SOUNDPROOFING POWER
Comparing the unique numbers from before and after the Sundar Vertical Garden installation, a 6 dB improvement can be observed. In particular, this improvement occurs at mid-high frequencies starting at 200 Hz with a maximum of 10 dB at 800 Hz.
REVERBERATION TIMEANALYSIS
The test setup included one loudspeaker position with three fixed microphone positions and with two decays measured at each position. With the Sundar Vertical Garden installed, the reverberation time decayed below 200 Hz and above 400 Hz.