FREE HVAC PE EXAM STUDY RESOURCES!

1: NCEES Tricks

The common ways NCEES will test you will be:

1.0.1 Try and throw you off by including extraneous and unnecessary information in the problem.  

This can cause you to have analysis paralysis because you are overwhelmed with information.  It can also make you second guess yourself. You start to wonder if you should be using this information that doesn’t seem to be needed for the solution you are formulating.

1.0.2 Asking for the answer in an obscure set of units and including numerically confusing answer options.  

What does that mean?  Oftentimes, they will ask for your answer in a different set of units than is common practice, or different units than what the given information would naturally result in.  Plus they’ll give that numerical value that you furiously punched out on your calculator as one of the answers, but will be in the wrong units.  The problem statement will ask for a different set of units.  A simple conversion calculation will give you the answer they are asking for.  It’s a shame to do all that work on the problem and not get credit for it because you didn’t pay attention to the units they were asking for.

1.0.3 Not giving you the exact numerical value as an answer possibility.  

For example, if the answer is 215 gpm, the closest answer on the problem may be 210 gpm.  The other answer choices should be far enough away from that value so that you can be reasonably confident that you have the right answer.  Sometimes the number may be closer such as 3.14 versus 3.48.  If you are unsure, double check your solution for mathematical mistakes and that you are using all the significant digits they give you.  Then choose the numerically closest value.  Be care to pay attention for things such as calculating pipe or duct size.  If you calculate proper duct size to be 8.18 inches diameter duct, you’ll want to use 8” duct, etc.

The best way to avoid these problems (or any other pitfalls that they may throw at you) is to follow my tried and true process for solving these problems.  This process will focus your mind and guide your efforts so that you won’t make these simple mistakes that cost you points on the test.  Learn this process early on and use it as you progress through your studying.  It will become second nature to you and will be something your mind implements almost instantaneously.

Let’s look in more detail at the best way to approach a problem on the PE exam.

2: Process for Tackling Problems

2.0.1 Read the entire problem statement.

The first step is critically important.  Read the entire problem statement!  Most people tend to rush in and start working on a solution.  Have you heard the expression “An ounce of prevention is worth a pound of cure?”  Well it certainly applies here.  Take a few seconds to read the problem statement so that you don’t waste your time going down the wrong path and wasting alot of time.  Spare a few seconds at the beginning for possibly minutes of precious test time later. When you’re reading, look at the information they give you and the units they give it in.  Look at the diagrams that are included, if any.  The goal is to see what all is included for you to work with.

2.0.2 Identify the heart of the question.

Look for exactly what they are looking for.  They may spend several sentence setting up a scenario and giving you tons of data. Then they will ask you for something very simple that has nothing to do with all that data they gave, or something easy that could be solved with the first thing they mentioned in the problem statement.  This is a critical step that is really at the heart of this process. Without nailing this down, you are spinning your wheels and wasting precious time.

2.0.3 Note the units they are asking for.

Part of identifying the heart of the question is actively noting the units that they are asking for.  They may give you all the data in one type of unit and then ask for the answer in another, just to check if you are paying attention. It’s an easy correct answer if you pay attention, or an easy mistake if you don’t.

2.0.4 Look at the solutions and their units.

It’s also important to look at the solutions and what units they are given in.  If they ask for the answer in feet and one of the answers is in inches, you can automatically cross that one out as a possibility.  Paying attention and getting in the habit of following these steps will help you identify these easy opportunities to narrow your choices.

2.0.5  Solve the problem.

Now that you know exactly what they are asking, and what units they are asking for, you have a targeted focus for developing a solution to the problem.  This focus will allow you to find equations and processes that are directly related to what they are asking.  You will also know exactly what you are searching for in your reference material.  Use the equations available to you and work towards finding a solution that is given in the answer choices.  If you tabbed your reference material properly (Link to BP 14 – Everything You Need to Know About the MERM) Since you paid attention to the units they asked for you’ll know immediately if any of the answers are disqualified because they are in different units than what the problem statement asked for.

2.0.6 Check your answer.

Once you have an answer and it’s in the right units, take a step back and do a quick check to make sure the answer makes sense logically.  Use your experience and common sense to make sure that the answer and the units make sense physically.  For example, if (include example about units being in feet and not logical and should be in inches.  Also include example of – sign versus + sign right direction).  Double check to make sure your answer is in the right units.  

Many times they will give numerical values as answers that are numbers you will obtain during intermediate steps of the solution.  They try to trick you by getting you to see that number as one of the answer possibilities and to select it and move on.  Don’t rush through your solution and fall for that trick!

3: Example Using The Process

Let’s put our knowledge of the best way to approach a problem on the PE exam into practice by looking at a couple of examples. These examples come directly from NCEES and were included on one of their practice tests.

3. 1 Example 1 – Extraneous Information

After reading the entire problem statement, you’ll see that the heart of the question is asking about how much cooling is required to take frozen chicken at 27 deg down to -10 deg.  The want the answer in BTU.

Example 1 problem statement

Since you know exactly what they are asking for and the units they want it in, you can find the right equation to obtain that answer.  

The heat transfer equation will yield the correct answer.  

You’ll see that to find the heat transfer in BTU, you’ll need the mass of the chicken, the specific heat of the chicken (below freezing since it’s at 27 deg to start with) and the temperature difference.

Example 1 problem solution

Notice how you didn’t need most of the information they gave you.  Who cares about the latent heat of fusion or the thermal conductivity?  You can feel confident that this information can be discarded if you are careful to note what they are asking for and in what units they want the answer.

Let’s look at another example.

3.2 Example 2 – Asking for Answer in Different Units

After reading the entire problem statement, you’ll see that they are asking for the operating head of the pump and they want the answer in feet.

Example problem 2 statement

The Bernoulli equation will give us the head required.

Example problem 2 solution

Once you set up the Bernoulli equation and solve for some factors using the pipe data they gave you, you’ll come up with an answer, 169 ft.

If you see 169 as an answer possibility and mark it and move on, you’ll miss the question.  That’s because we haven’t given the EXACT answer they asked for.  They want the operating head of the pump.  We’ll have to subtract the pressure at the inlet, after converting it from psi to ft.

This additional step yields the operating head of the pump to be 126 ft.  The nearest answer on the list is 124 ft, which is the correct answer.

Notice you didn’t need to know the temperature of the water (90 deg).  Get comfortable not using all the information given and leaving some of it on the table.

3.3 Writing Out The Solution

It’s critical to write out the solution to problems by hand.  You need that mind muscle connection between your hand and your brain.  Writing out the solution makes your brain think through each step of the process and you develop a better understanding of the material.  You can even keep a notebook of problems and solutions that you can reference on the test.

It is great to look at solutions as you are studying, but don’t rely on that alone.  You must write them out at some point for complete understanding.

4: The Best Way to Approach a Problem on the PE Exam – Bottom Line

The makers of the PE exam will test you on more than just your knowledge of the subject matter and ability to get to an answer.  They like to trip you up by including extraneous information to make you second guess yourself.  They will also ask you for the answer in different units than what you would expect.

Following the process outlined above will help you eliminate simple mistakes.  These simple mistakes cost you points and precious time on the exam.  

Learn the best way to approach a problem on the PE exam early on. Use it on every problem during the course of your studying.  It will become second nature to you after time.