What I do at work:

Whenever people ask me exactly what I do at work, I find it very hard to describe. I usually give them a vague reply like “I design the mechanical systems in buildings”. Although, I know that this doesn’t really mean much to most people. So I thought I’d write a blog post where I try to actually explain what I do at work.

The mechanical systems that I design are the heating, ventilation, air conditioning and plumbing systems within buildings. This might sound straightforward but there are a lot of different variables involved.

The first thing that needs to be determined is which type of systems will be used and how heating and cooling will be provided. Most commonly, an air handling unit is used to heat and cool air which is then blown into the space that you are trying to heat or cool.

There are a few different options for how heating and cooling will be provided. Here are some examples of how the air can be heated within the air handler:

-Hot Water Coils: Hot water runs through metal coils and a fan blows the air over the coils so that the heat will transfer from the hot water to the air.
-Electric heat: Air is heated by being blown over electric heating coils.
-Gas heat: Gas is burned within the units to heat the air.

Every system has pros and cons. For example, hot water coils are very efficient but require a lot of space because a boiler is required to heat the hot water (and pumps to circulate the hot water).

Once you’ve figured out how you are going to provide heating and cooling, you need to figure out how you are going to keep all of the spaces that the air handler services comfortable at the same time. The air handler will service many different spaces and they won’t always need the same amount of heating and cooling. Here are a couple different options for that:

-Control Air Volume (CAV) Systems with terminal re-heat: Use your air handler to heat the air to the lowest temperature required by any of the spaces you are controlling. Then use a small re-heat unit in each space to increase the temperature for just that space to whatever it requires. (Now you have to go back and determine how you will provide this heat - hot water or electric?).
-Variable Air Volume (VAV) Systems: Use your air handler to heat the air to be really hot (or really cold) but control the amount of air which flows into each room. If a room is already a good temperature, don’t supply it with air. If a room is really cold, provide it will lots of air. Etc...

Each of these systems has their own pros and cons. A CAV system is great if your rooms will usually all need the same amount of heating and cooling but a VAV system is better if there is lots of variation between the rooms.

Next, you need to determine how much heating and cooling each space will likely require. This is done by determining where you will loose heat and where you will gain heat. For example, windows will make the space loose heat and people will make the space gain heat. This is important so that you can determine how much airflow each room will need and how large your air handling unit must be.

Once you’ve decided all of that, you need to determine how you will get the air to the space (i.e. with ductwork). This requires lots of coordination with the architect and structural engineer to make sure that ducts will fit within the ceiling space.

Once you’ve brought the air into each room, you need to select diffusers appropriate for the space. When selecting diffusers, it is important to consider noise and speed. You don’t want your diffusers to be sending out so much air that they make a whistling noise or that people feel drafts of hot (or cold) air blowing on them.

Ultimately, what I love about my job is that every day is different because every building is different. This means that I am constantly learning and everyday provides a new challenge.

The classes that most strongly relate to what I do at work are heat transfer and fluid mechanics.

It's Just Rocket Science!

In high school physics class, students learn how to calculate the speed and acceleration caused by forces acting on an object and the forces that occur when objects interact with one another. But what happens when you have a constant stream of fluid on an object? How can you calculate and analyze the force applied by a fluid?

The answer is through the study of Fluid Mechanics. It was my favourite course last term. I think it is really cool to be able to analyze the pressure and forces that a fluid will exert on an object and it is useful for so many different applications!

Fluid mechanics is used in the design of the following:

-Rocket Science – It is a knowledge of fluid mechanics that allows engineers to design rockets. They need to determine how much gas must be produced through combustion to propel the rocket at the acceleration that it needs.

-Aerodynamics of cars – The shape of a car can drastically change its performance. Cars are designed to allow the air to flow smoothly across them without creating too much drag (which really slows cars down). A car without much drag is much more fuel efficient – so this is pretty important!

- Environmental water systems such as dams – A dam has to be built to be strong enough to support the weight of the water it holds, so it is really important to be able to calculate how much force the water will exert on the dam

-Air planes – What makes a plane fly? Fluid Mechanics! The shape of planes’ wings are designed so that when the air passes around them, more force is exerted on the bottom of the wing and this pushes the whole plane upwards. Without a knowledge of fluid mechanics we definitely wouldn’t have the amazing huge planes that we have today.

As you can see, fluid mechanics has a lot of important applications, which makes it pretty interesting. Plus, it's pretty cool to be able to say that you really are studying rocket science!

Design Symposium

Well, I was intending on finding some pictures and getting permissions to post them from the people in them and the people who took them. However, as this draught has just turned one week old, I'll post it now, and come back and edit with pictures later.

One of the things that everyone in engineering at Waterloo has to do is a fourth year project. This varies from department to department, but what MME (Mechanical and Mechatronics Engineering) students do is to tackle a design project. There's two courses to this - ME 481 in the 4A term, where we have to design something, and then come up with enough detailed drawings, component lists, etc that we could give our final report to someone who knew nothing else about the project, and get it made exactly right. The second course is ME 482, in 4B. For Mechanical students this is optional, but for those of us in Mechatronics it's mandatory. This is where you build the project, and discover all the places where you left out information in the design phase.

On Monday, all the Mechatronics students had the penultimate part of our course. We took our finished projects and went to the great hall in the student life centre to set up our symposium. For four hours, we took questions from visitors to campus - lots of parents came, younger engineering students- especially the third year mechatronics students who have to do this next year, and other students who to figure out why the chairs that normally sit in the great hall had been moved.

My project was an automated window. Basically the relevant parts are that it will open and close itself, based on how warm it feels inside and outside. There's a couple of manual overrides, and a few other constraints on how it works, but those weren't why we made it. Basically we wanted to make something that would encourage green technology, things like opening the windows instead of turning on the A/C.

My partner and I were kept talking all afternoon, explaining to people what the project was. There were a surprisingly large number of people.

Mechatronics - Nut Sorter Project

One of the exciting things that I have done in Mechatronics so far is this Nut Sorter Project.

The idea is to design a Mechatronics system that can sort nut of different sizes and types. It should also be able to detect coins in the process and reject them. There were size constrains as to how big the sorter can be and we also had a budget that we had to work within.

At the start of the term we were given a kit that contained some sensors, stepper and DC motors and some basic electronics components. At the end of the term a competition was held to evaluate the sorter based on speed, accuracy and design.

Here is the picture of the nut sorter that our group had designed. This sorter works based on the shadow a nut casts. Depending on the size of the shadow, the nut is dispensed into the respective bin.

Attached are two of the videos that shows how the sorter works





Enjoy the videos. You can look at other nut sorter projects on Youtube.

Co-op Experiences as a Mechatronics Undergrad

Mechatronics Engineering is a combination of Mechanical and Electrical Engineering which has given me very broad opportunities. Through my work terms I have gained experience working on sheet metal enclosures for high voltage switches, working at a high tech company that makes software and working for a building design consulting company.

My favorite work experiences have been doing building design consulting. Through my work terms in building design, I have worked on the renovation of the UW Dana Porter Library and on the design of the new Waterloo Regional History Museum. Both projects were full of learning opportunities and it was amazing to work on buildings that are so important to the community that I live in.

Through this position, I did both Mechanical and Electrical building design. Mechanical building design includes: heating, ventilation and air conditioning systems, sizing air flows, ducts and pipes and ensuring temperature and humidity requirements can be met and maintained all year round. Electrical building design includes: service load calculations, lighting calculations and ensuring user requirements for lighting and power were satisfied.

One of the most important parts of design is ensuring that the design is actually possible in the real world. This means that a lot of time is spent coordinating with all of the other engineers and architects involved in the building design process to make sure that everything will fit and work together seamlessly.

In addition to doing design work, I was also given opportunities to interact with clients and partnering firms. People skills are a very important part of my job as an engineer because it is important to be able to explain technical results and findings to clients in a way that they will understand. Organizational skills are also essential to my work because I always have many deadlines and milestones that I need to keep track of, as well as, long lists of things which must be designed, verified or confirmed.

The Waterloo Regional History Museum

One of the most exciting aspects of my work in building design has been the opportunity to work on environmentally friendly buildings. The museum that I worked on has been designed to be very environmentally friendly. A couple of the things that are being incorporated into the museum include rainwater collection, and energy recovery systems.