8-5-2024: The HVAC&R Weekly Edition: Issue #8
They were a nomadic tribe, triangulating their way across the Great Plains of the Midwest. Governed by The Law of Sines and Cosines, they were lost, they were nerds, they were the "Fugawe" Indians.
Now, if my High School math teacher had introduced Trigonometry to me using that as on opening line, I would have probably faired a whole lot better. If you were anything like me Algebra and Trigonometry were not my favorite subjects. I just could not see the need to know the height of a Saguaro cacti based on the angle of the sun and its casting shadow, or which runaway train was going to crash into Union Station first.
Little did I know, years later I would be using these same math skills to avoid obstacles in crowded mechanical rooms. And that I would be calculating how many gallons of a 20% Glycol Solution I would have to drain from a 2,500 gallon system, and replace that amount with 100% glycol to achieve a 40% Glycol mix.**
By now you’ve probably surmised that we are not going to be sizing refrigerant piping in this next Series, maybe next time. I thought it might be nice to share some techniques that might allow you to avoid those obstacles and challenges you may encounter in a crowded mechanical room on your next Chiller replacement project. Of course it can be applied to any piping challenge you may came across. I assume some of you are working for Service Contractors that have Project Teams, and I feel some of these techniques may be helpful. These are generally for weld type piping connections.
I want to establish some very basic ground rules regarding triangles whether they’re acute, obtuse, or 90° right triangles. I only mention acute triangles where all angles are less than 90°and obtuse triangles which have one angle greater than 90°because some of the rules apply to them as well as right triangles. Today our primary focus will be on 90° right triangles.
Here are the more important rules.
All interior angles of any triangle will total 180°
With 90° right triangles the two acute angles will equal 90°
With 90° right triangles subtracting one acute angle from 90° will equal the remaining acute angle.
The longest side of a 90° right triangle is always opposite the 90 angle. It is referred to as the hypotenuse.
The smallest angle in a 90° right triangle is always opposite the shortest leg of the triangle.
The largest acute angle in a 90° degree triangle is always opposite the longest leg of the triangle excluding the hypotenuse.
Pretty simple rules to follow and likely ones that you were familiar with.
AN EXAMPLE OF THE 6 RULES FOR 90° RIGHT TRIANGLES
AN EXAMPLE OF THE 6 RULES FOR 90° RIGHT TRIANGLES
Please join me to become an honorary member of the Fugawes’ as we look at Basic Right Triangle Trigonometry and explore how it can be applied to some specialized piping offset formulas in the upcoming Issues.
I would appreciate your feed back so please leave a comment, or if you have any questions please feel free to reach out. If you know someone that may find this kind of information helpful please feel free to share.
Be safe and have a good week.
P.S. **You need to drain 625 gallons of the 20% solution and replace it with 100% glycol.
But what does Fugawe mean?