Proposal
Do plants affect thermal comfort of ambient air?
Design Proposal
In hopes of expanding a 'simple technology' used to mitigate heat, plants, I am exploring the incorporation of a vegetative filter between an interior space and its exterior environment.
In my background research and literature review, similar experiments and data collections have been conducted to explore ways that plans mitigate heat as it occurs in various settings: tree covering to address the heat island effect in urban environments, introducing plants to improve thermal comfort and air quality for occupants inside an interior space, and vernacular building construction methods such as a lifted, thatched roof in humid sub-tropical climates like Malawi.
I am focusing on and expanding upon the research around the effects plants have on thermal comfort. By measuring dew point and absolute humidity, I will monitor the effects the plants have on thermal comfort of the space. Evapotranspiration is "the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants"... "the process by which plants absorb water through their roots and release it as vapor through their leaves. Both of these liquid-to-gas processes use heat from the surroundings and thus cool the air." (https://coolcalifornia.arb.ca.gov/how-cool-vegetation-works#:~:text=Evapotranpiration,and%20thus%20cool%20the%20air.)
I hypothesize that the addition of my 'planted filter' will cause transpiration from the plants, subsequently making the air temperature feel cooler, as long as the temperature remains within a comfortable range.
Please see diagram below outlining this experiment.
In my background research and literature review, similar experiments and data collections have been conducted to explore ways that plans mitigate heat as it occurs in various settings: tree covering to address the heat island effect in urban environments, introducing plants to improve thermal comfort and air quality for occupants inside an interior space, and vernacular building construction methods such as a lifted, thatched roof in humid sub-tropical climates like Malawi.
I am focusing on and expanding upon the research around the effects plants have on thermal comfort. By measuring dew point and absolute humidity, I will monitor the effects the plants have on thermal comfort of the space. Evapotranspiration is "the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants"... "the process by which plants absorb water through their roots and release it as vapor through their leaves. Both of these liquid-to-gas processes use heat from the surroundings and thus cool the air." (https://coolcalifornia.arb.ca.gov/how-cool-vegetation-works#:~:text=Evapotranpiration,and%20thus%20cool%20the%20air.)
I hypothesize that the addition of my 'planted filter' will cause transpiration from the plants, subsequently making the air temperature feel cooler, as long as the temperature remains within a comfortable range.
Please see diagram below outlining this experiment.
Mockup
Lessons Learned:
1. Box with wind velocity sensor (green multi-use sensor from class) inside of it. Started out with just an intake hole where I supplied air into the box using a handheld fan. The measurement read as X. Then, I added a hole to the opposite side of the box, across and off-center from the intake hole, to serve as an outlet for the air to escape from. By adding this outlet to the box, the wind velocity increased to X. This prototype informed me that it will be best if I can have a way for air to escape from 'space 2' and will aid in the movement of the air from space one/through the vegetative filter.
1. Box with wind velocity sensor (green multi-use sensor from class) inside of it. Started out with just an intake hole where I supplied air into the box using a handheld fan. The measurement read as X. Then, I added a hole to the opposite side of the box, across and off-center from the intake hole, to serve as an outlet for the air to escape from. By adding this outlet to the box, the wind velocity increased to X. This prototype informed me that it will be best if I can have a way for air to escape from 'space 2' and will aid in the movement of the air from space one/through the vegetative filter.
2. Two Spaces with Vegetative Filter Between Them
Use fans to circulate air into the experiment (Space 1). Measure the relative humidity (RH) and temperature of the air within Space 1. As the fan forces air from Space 1 through the experiment 'vegetative filter' (an assembly of wood and a layer of Fescue grass exposed such that 50% of the surface area becomes the only way air can pass into Space 2, forced to filter through the grass). Measure relative humidity and temperature on the far side of the assembly (Space 2).
REPEAT with 25% and 75% (if time permits).
'vegetative filter': a layer of wood structure with 50% of the experiment surface area removed to allow air to pass at a controlled rate and lined with metal mesh on either side of a frame containing a 9x11" rectangle of Fescue grass sod.
Use fans to circulate air into the experiment (Space 1). Measure the relative humidity (RH) and temperature of the air within Space 1. As the fan forces air from Space 1 through the experiment 'vegetative filter' (an assembly of wood and a layer of Fescue grass exposed such that 50% of the surface area becomes the only way air can pass into Space 2, forced to filter through the grass). Measure relative humidity and temperature on the far side of the assembly (Space 2).
REPEAT with 25% and 75% (if time permits).
'vegetative filter': a layer of wood structure with 50% of the experiment surface area removed to allow air to pass at a controlled rate and lined with metal mesh on either side of a frame containing a 9x11" rectangle of Fescue grass sod.