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mechanical engineering

Flowing Water at 22 Degrees Fahrenheit

Flowing Water at 22 Degrees Fahrenheit

By Energy Rant No Comments
As undergraduate mechanical engineering students, we took materials science courses and studied phase diagrams like the one below from “Metallurgy for Dummies.” Does that appear to be dummy-grade to you? It gave me a chuckle. A phase diagram for water (below) is decidedly simpler. The above diagram shows only liquid and solid phases of carbon steel, while the water diagram shows its three phases, solid (ice), liquid, and vapor (steam). The author writes, “Freezing Point: At a temperature of 0 °C and a pressure of 1.00 atm, this is the point at which water (liquid) freezes into ice (a solid).”…
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Dig Some Wind – Blown Away by Inversions

By Energy Rant 2 Comments
As children, some engineers liked to take things apart to see how they worked – and maybe even put them back together. That was too much work for me, but I was curious. I would intently watch my Mom as she accelerated the 1970s Ford Galaxy 500 down the road. What was she doing to make it shift gears? I had to know! Of course, it was an automatic transmission. Today, I see some scientific claims, and I can’t help myself but to dig in and find the big lie, er, the big why. This week’s adventure started two months…
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Four Shades of Electrical Demand – A Riveting Cliffhanger

By Energy Rant One Comment
Last week I related electrical demand in kW with electrical energy in kWh. Energy is the area (power times time) under the kW curve. Without cheating, I’ll do an example. Elementary Calculus In energy-nerd world, a curve is a line of any form, including a straight line. Consider the simple ax + b curve on the right, where a is the slope and b is the y-intercept.  The equation is y = 2x +4. C’mon you had this in elementary school. Challenge yourself!If I want the energy consumed from hour two to hour ten, I simply take the integral of…
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Governors Crush Shaheen-Portman

By Energy Efficiency, Energy Rant, Government 5 Comments
This week’s post is brought to you by the National Resources Defense Council.  Yes indeed; states are leading the way in energy efficiency and  considering the bumbling federal government that can’t get anything done or come close to living within its means,  supporters of Shaheen-Portman in our industry should think long and hard or short and easy about what they wish for. Most states have a genuine interest in the well being of their citizens across the entire state.  They balance their budgets, sometimes by force (law), and this is also the expectation of state governments and citizens alike.  Expectations…
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Duct Leakage Chaff

By Energy Efficiency, Energy Rant 3 Comments
Due to duct leakage, only 57% of heat generated in a home furnace is delivered to conditioned spaces.  OMG!  Run for your lives.  Big deal. I have overheard conversations at conferences and other networking gigs that include statements like, “We are so focused on envelope tightness, insulation, energy-saving windows, and efficient appliances, but meanwhile we are wasting almost half the heat produced in an energy efficient furnace.”  Not so fast. In mechanical engineering, we have the first and second laws of thermodynamics.  The first law is like a change machine – conservation of money.  Put a piece of cotton-infused paper…
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Hannibal, Max and Me

By Energy Efficiency, Energy Rant, Retrocommissioning (RCx) No Comments
I hate electricity.  I love what it allows me to do but I just don’t understand it.  I sat through an in-house safety training session on arc flash, which I actually understood – there is a huge burst of energy through a “fault” that melts and actually vaporizes the copper conductor, which expands 7,000 times at Mach 2 and 1 million degrees F (made up numbers but the premise is correct).  It’s one heck of an explosion.  During a break I was asking our electrical engineers what the difference between a neutral and ground was, the flow of electrons, the…
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