Posts tagged clean air
Biowalls Explored in More Detail
Feb 25th
Biowall
A 24-square meter plant wall – more specifically a “biowall” – was built in the Robertson Building. The biowall was planted with a variety of exotic and native indoor flowering plants. Each plant has its own pocket in a special planting material (they don’t tell you the exact fabric they use). Water filters through the material to the plants’ roots and fresh air is continually pumped into the room via the living biowall.
The biowall purifies and cleans the air. The plants were chosen for their ability to tolerate indoor lighting conditions and their ability to improve indoor air quality. Some of the common contaminants come from traffic outdoors as well as off-gassing from furniture, paints, drywall, photocopiers, and human fragrances in the building.
The biowall helps filter Volatile Organic Compounds or VOC’s. VOC’s are actually a group of pollutants indoors and out. While small concentrations of these chemicals aren’t dangerous, over time they can contribute to “sick building syndrome,” which can include eye, nose, and throat irritation, headaches, and dizziness.
The biowall only needs typical plant maintenance including occasional dusting and removal of wilting foliage. Two 1000 watt lights provide supplemental lighting.
Living Biowall
A separate biowall was installed in the IL Centre. It’s 3 stories high and is aesthetically pleasing as well as acting as a biofilter which removes the VOCs and CO2 from the air.
Plants are easily swapped if they don’t thrive. The plants that work on the wall will vary depending on its requirements. Leafy ferns do better than Hibiscus, and orchids have done very well. Here’s a rundown of the plants used in the biowall:
- Aglaonema (Algaomema commutatum) & Spathiphyllum spp. (mixed aroids)
- Spider plant (Chlorophytum)
- Croton (Codiaeum)
- Cordyline
- Dragon Plant (Dracaena)
- Ficus (verigated)
- Rubber Plant (Ficus Elastica)
- Ivy (Hedera)
- Palms (Dypsis, Howea, or Chamaedorea spp.)
- Maidenhair Fern (Adiantum)
- Philodendron (several species)
- Snake plant (Sansevieria)
- Purple Heart (Setcreasea pallida, similar to the common Tradescantia)
- Umbrella Plant (Schlefera)
Diagram of basic biowall setup
Two layers of a porous material make up the fabric attached to the concrete wall. It’s 1 inch thick and is made of loosely woven plastic screwed to the wall in pieces. The top layer has slits cut into it where the plants are placed. The roots hold the plants in place and grow between the layers. The plants chosen don’t spread pollen and the constantly running water and fresh air prevent mold. A vapour barrier was installed in front of the concrete and behind the drywall to prevent moisture from spreading. What makes this vertical garden into a biowall are the fans that draw the air from each of the three floors to circulate through the building. You can see an informative flash image at queensu.
Biowall – Morristown Building Goes Green
Feb 17th
Biowall
The Geraldine R. Dodge Foundation installed a biowall in their New Jersey building. The bio-wall is a 3 story (38 ft tall by 14 ft wide) vertical garden that uses a water and air permeable growing media. That allows the air to blow right by the roots which take the VOC’s right out of the air.
Multiple studies have been done showing the it’s actually the roots that take most Volatile Organic Compounds out of the air.. not the plant leaves. The roots are able to completely break down many of the VOC’s and even use some of the results of the process for food. A biowall can potentially replace a complete air exchange system if done correctly.
This biowall was integrated with the HVAC system so that the air is pulled through the plants and the growing media and into the HVAC system behind it which in turn circulates it through the building. So while most living walls use a passive system to clean the air by the plants naturally removing the CO2 and few VOC’s, this goes a step further and, through the roots of the plants, becomes extremely effective at removing a large amount of VOC’s.
An advantage to this system is that the air doesn’t need to be reheated or recooled as other ventilation systems do when they exchange air from outside… thereby saving energy. The air is simply returned through the room through the raised floor duct system.
The plants were placed into pockets from slits in the fabric. The plants are watered hydroponically with the water dripping down from the top, ending in a trouph, then getting pumped back up to the top again. There’s a biowall video below, and it’s definitely worth watching. You can see the planting in action there.
Biofilter wall
Biowall filter
Natural air cleaning
Feb 9th
St. Gabriel's Parish living wall 3m x 8m
Nedlaw Living Walls make living walls with a purpose – to clean out indoor air pollutants and allergens. It’s a different focus than standard living walls/vertical gardens. Given the correct installation of the living walls, they can actually replace traditional air filters in your home.
The leaves of the plants change the carbon dioxide into oxygen, but it’s the roots of the plants that take out most of the chemicals according to multiple studies. The living walls from Naturaire facilitate the process of the air cleaning by using a fan and drawing air from the home through the roots of the plants and back out into the room. That process helps clean out the home of the over 300 voc’s (volatile organic compounds) that can potentially be found there.
The living wall system can degrade and breakdown the VOC’s quickly and naturally, even in large volumes of air and acts as a completely natural biofilter. Since they no only can capture, but also breakdown the VOC’s, they end up being able to remove many harmful pollutants that other air filters can’t. According to their website, the air quality of a space relying almost entirely on an active living wall is at least as good as a similar indoor space using a high-tech ventilation system that replaces the building air up to six times per hour.
You can make the living wall system an active biofilter in one of two ways: hooking it up to the HVAC or using a fan in the back of the living wall. The HVAC is the most effective way because it can filter the air of the whole house. The air is drawn through the living wall and cleaned, then into the HVAC system and then disseminated through the house. The second method works as well, but is more localized as it just draws and circulates the air from a particular room.
Remington Group Living Wall freestanding 2 sided wall 35 meters square
How well does the system work?
During studies at the University of Guelph, common indoor air pollutants were released into the air to determine the living wall’s effect on the VOC’s. A single pass through the Living Wall removed up to 80% of the formaldehyde, 50% of the toluene and 10% of TCE (trichloroethylene). The filter is only 5 cm thick, but the ability to have such a strong effect on the chemicals is amazing.
“Concentrations of toluene and formaldehyde in the aquatic system did not increase during the four-week experiment, suggesting that these materials were readily metabolized. TCE levels in the aquatic system initially did increase slightly, but then plateaued, suggesting a possible capability to degrade this compound. Even before the challenge, we knew that two to three percent of the bacteria present had the ability to break down VOCs.” -From their website
“Through photosynthesis, green plants are able to convert CO2 — which is considered an indoor pollutant — into oxygen. The true impact of this on indoor air quality is minor. To be a true CO2 scrubber would require over 10m2 of wall per occupant instead of the typical 0.2m2required to provide clean air.”
How big do you want the living wall?
The suggested dimensions are 1 square meter or yard of active living wall or biofilter (a living wall with an air circulation system attached) for every 100 square feet of floor space.
Remington Vertical Garden
WESST Corporation (Women’s Economic Self-Sufficiency Team) 420 sq ft
Living walls home owner
Sassafraz Restaurant, Toronto living wall 22 sq meters
Office Divider Greenery
Jan 13th
Here’s a green idea for an office divider. It’s a living wall that’s moveable so you can slide it wherever you want in an office. This is a great youtube video with the interviewer getting solid information about how to build a living wall. You can make the vertical garden different colours depending on what plants you use and some of the benefits of having a living wall are explained in the video such as cleaning the air of a building. This vertical garden used 4 layers of felt and is made of polyester so it doesn’t rot or break down over time.
