Background Research

Greenhouse Ventilation Systems

Small-scale Greenhouse
(Google Image)

Large Scale Green house
(Google Image)

Green House has been widely renowned and highly-used over this past few years especially in botanical fields. Green house is defined as a building structure, primarily of glass, in which plants that need shelter from cold weather are grown. These plants are generally kept under controlled conditions in order for them to thrive and grow.Temperature and humidity can be controlled for the cultivation or protection of plants. 

Greenhouse  Simple Air ventilation
(Google Image)

In relation to our Thermally Responsive Muscle Fiber project which is merely on the innovation of the green house’s windows, some of the specifications about green house has been determined to help generates a better idea and concept on our project. We found that the main part of greenhouse that we should be focusing on is its ventilation systems.

There are four parts of ventilation imperative functions :-

Temperature Control

Greenhouses trap solar radiation thereby raising the temperature in the environment (the greenhouse effect). If this heat is not removed from the environment it can cause undesirable conditions for plant growth or worse. Ventilation systems, whether natural (passive) or mechanical (powered), serve the basic function of the removal of excess heat.

Humidity Control

Like heat, high concentrations of humidity can become trapped in a greenhouse’s environment. Although some varieties of plants thrive in high humidity conditions, most plants are hindered by the pathogens associated with high humidity levels. Just about every mold, fungus, and mildew thrive in high humidity conditions. Plants transpire moisture that, if not removed, can build up in a greenhouse, raising the humidity levels. It is also very common for the environment within a greenhouse to be affected by the dew point which causes condensation and excess humidity.

CO2 / Oxygen Replacement

Just as humans would run out of oxygen in a poorly ventilated and enclosed area, plants “breath” CO2 which needs to be replenished in any greenhouse that is not supplementing it artificially. Fresh air drawn into a greenhouse carries with it two important gases needed by plants to carry out some of their most basic functions. During photosynthesis, plants use CO2 which they acquire directly from the air. When CO2 levels decrease the rate of photosynthesis and all other plant functions associated with photosynthesis decrease accordingly. Maintaining an adequate level of fresh air intake guarantees sufficient CO2 levels for plant growth.

Air Circulation

Air circulation, or air movement, within a greenhouse serves many purposes. Proper air circulation Grow Vent creates uniformity in temperature, humidity, CO2, and oxygen within the environment. Plants respond better to environmental consistency and proper air circulation ensures each plant within the greenhouse receives the same atmospheric conditions. Air movement is also our way to simulate the wind in an enclosed environment. Wind strengthens the cell walls of a plant’s stem and directly influences the architectural integrity of plant growth. For many plants wind (or the simulation of) serves an even more integral purpose: pollination. Many vegetable and ornamental plants are pollinated via the wind. Air movement within a greenhouse could be the determining factor as to whether a plant is pollinated and able to complete its reproductive cycle.

Thus, our project of thermally response muscle fiber shall achieve most parts of these greenhouse requirements and will somehow be beneficial in the future. 



Fishing Line Categories 

One of the components for the thermally muscle fiber is fishing line.  Yes, it is typical materials that can be found in our "Walmart" yet it characteristics make it suitable component for the muscle fiber.  Its well-known strength is major characteristics that we take count on.  In order to get the window for the greenhouse works in controlled condition, the strength of the fishing line is important.

There are many types of fishing lines in store. Hence, we have to research the characteristics for each of the fishing lines and pick the best to suit well in our project. Below are the following fishing lines and their characteristics :-


Monofilament Fishing Line

This type of fishing line is the most familiar and widely used.  The beneficial advantage for the single-strand nylon line is it is easy to tie knot and has extremely good knot strength.  Other than that, it has a significant amount of stretch which is 25%.   This can be advantageous to our window which can be used as shock absorption.   Although it has great strength, it actually can absorbs a good amount of pressure.

Copolymer and Hybrid Fishing Line

This kind of fishing line consist of two polymers or non-polymer which combine to create inner and outer layer of the fishing lines. The manufactured lines have less memory-shape retention.  The lines have a better knot strength but can be trickier to tie well-holding knots. The idea of the copolymer lines are being replaced by new hybrid lines.  These lines are actually combination of two dissimilar materials like fluorocarbon and nylon to create better lines with the best characteristics in a single strand.  



Sewing Thread Categories

A great fishing line must be combined with a great sewing thread to generate great muscle fibers. Surprisingly, there are many types of sewing thread. Knowing which thread to choose for this project is the key part of a successful outcome. Therefore, we count on the tensile strength, the durability and the elasticity for the selection of the best sewing thread.

Below are the following sewing threads that strike our taste and their properties :-

Nylon Thread

Nylon is a polyamide fiber, derived from a diamine and dicarboxylic acid. It is one of the most widely used synthetic threads in the world. Its high strength-to-thickness ratio, abrasion resistance, ease of sewing and relatively low cost are the key reasons for this success. The bottom-line is that nylon seems last "forever".  A middleweight nylon thread has a tensile strength of about 15 lb. At that strength there are very few people who can break it just by pulling. Kevlar is the exception with a 35 lb tensile strength. But is costs $130/lb compared $20/lb for nylon. Nylon thread stands up heat but not fire retardant. It yellows at 300°F sticks at 445°F and melts at 500°F. Nylon thread has excellent resistance at mildew, aging and abrasion. Nylon thread stretches about 25%. This means that 12 inches of Nylon will stretch to 15 inches over time. This is usually good because it lets your seems adjust to movement and changes in temperature.

Polyester Thread

Polyester is a category of polymers which contain the ester functional group in their main chain. Polyester thread looks, feels and performs like Nylon thread. But, there is one important difference - Polyester thread has superior resistance to UV sunlight, mildew and abrasion. But, there may be some loss of strength with prolonged sunlight exposure. It sticks at 440°F and melts at 483°F.