Variable Air Volume HVAC Systems
“How can we make a more optimal HVAC system?”
While Constant Air Volume HVAC Systems are affordable, they are not the most optimal solution. They don’t have the most precise temperature control, their fans can be noisy, and they can consume a large amount of energy. So how can we use our engineering mindset to solve this problem? Well, what if we were to have our air temperature be constant instead of our air supply? This would allow us to change the air temperature at a specified rate, allowing us to save money, energy, noise, and wear. This system is known as a Variable Air Volume HVAC System and is used in building systems all over the world.
Constant Air Volume HVAC Systems
“How can we make an affordable HVAC system?”
Most buildings are heated and cooled by a supply of air from an HVAC system. But many times, we are under financial constraints. So how can we make a simple and affordable HVAC air supply system? Well, what if we were to just fill the room with a constant supply of air while varying the temperature to meet our needs. Since we don’t have to monitor the air volume entering the system, we won’t have to build an extra control system, while still achieving our temperature setpoints. These systems are called Constant Air Volume HVAC Systems and are often used in smaller building areas.
“What happens to electronics when they wear out?”
Electronics are embedded into the fabric of everyday life. Whether it be in the computers we work with, the batteries to run our cars or the smartphones that we use to communicate with our friends. However, after a while, these items will become worn down by continual use and must be discarded. So how exactly does the waste process for electronics work?
Before we begin any process, we must recognize that electronics have toxic chemicals. These chemicals make it particularly difficult for dealing with electronic waste in any normal sort of fashion since improper disposal in a landfill can wreck hazards on the local environment. Since electronic waste fits into its own special category, such material has been labeled as E-waste.
To properly get rid of E-waste, individuals must bring it to a special E-waste processing facility. These units can intake all discarded electronics such as monitors, cell phones, radios, televisions, and computers and recycle all useable parts. E-waste facilities are a great way to deal with hazardous electronic waste.
“How can we measure the difference between a control signal and a half phase shift?”
When working with electronic amplifiers, the phase of an input signal might be shifted, which might introduce instability. And if this phase shift is greater than 180 degrees, then the system will be unstable. To standardize all measurements, electronics researchers have introduced the concept of a phase margin, or how far off from a 180-degree phase shift this new phase is. The phase margin can be calculated with the simple equation P_margin = |180-phase|.
“What is the margin of stability for a gain Bode Plot?”
One of the most useful features of a Bode Plot is the ability to find the stability of a system. One way to do that is to find the frequency at which the phase shift becomes 180 degrees, get the amplitude of the gain at the point, and then make a gain margin extending out to both sides equal to the magnitude of 1/|Amplitude value|, such that anything within that range will be stable.
“What are steady oscillations called?”
Many physical systems exhibit oscillating behavior. However, the natures of these oscillations can be different from one another. And in the most ideal oscillations, the amplitude is constant and unchanging. These oscillations are known as undamped oscillations and are rarely found outside equations and simulations.
“How can we make an energy efficient and evenly spaced heating system?”
Most traditional space heating systems push heated gas through air ducts to warm the surrounding area. However, this system is energy inefficient and creates an unevenly heated area. So how can we use our engineering mindset to solve this problem? Well, what if instead of shoving a fluid over the ground, we actually run it underground, through the tiling of the building? And instead of using a gas, we use a boiler to cycle out heated water and cycle in cooled water? This system would allow for evenly distributed heating through the tiles, as well as use less energy to heat the fluid. This system is known as hydronic heating and is rapidly gaining popularity throughout the world.
“What happens when a system’s oscillations actually destroy it?”
Mechanical systems have a tendency to oscillate until stability when their bodies are deformed. However, sometimes the oscillations are so powerful that they actually end up destroying the system itself! This phenomenon is known as a resonance disaster, and a most unfortunate example is the Tacoma Narrows Bridge when high-speed winds actually caused a bridge in the American State of Washington to shake into rupture.
The State Postulate
“What is the minimum amount of properties do we need to specify a thermodynamic system?”
In Thermodynamics, systems need to be specified by properties. But what is the minimum amount of properties do we need to specify a thermodynamic system? Well, after many hard years of research, Thermodynamicists have developed something known as the state postulate. With the State Postulate only two independent intrinsic variables are needed to specify a system. Once we have these variables, everything else can be derived through relationships.