World’s Largest Thermal Energy Storage Starts Up
The biggest impediment in using renewable energy (solar and wind) is that it is intermittent. That is, the wind doesn’t blow all the time and solar energy depends on the time of day and weather. Energy storage is a key way these renewable energy sources can be made more useful. A 14.9 million gallon tank in Germany will […]
Páternoster: The Continuously Moving Elevator
Instead of carrying things up inclines or stairs, a variety of methods have been invented to move people and things vertically – an interesting example is the páternoster. The páternoster is a continuously running elevator that was first developed in the late 19th century, and there are still a number of surviving examples like this one […]
Paper a Roof to Save Cooling Energy
Northeastern University researchers have developed a new “paper” that, when applied to roofs, can dramatically reduce cooling loads. The paper is made of hydroxyapatite materials spun into fibers and made into a paper. Its white color reflects the majority of the direct rays from the sun. In addition, heat from inside the structure is radiated […]
DTC Is Going To Be at AHR Expo 2023
The DTC Team is heading to Atlanta in February, and we hope to see you there at our AHR Expo Booth (BC1613). We’ll be giving away free courses, and offering a 20% show discount on all our courses. So drop by, meet Dr. Tom, learn firsthand what makes our Mechanical PE Exam Review courses so […]
“DTC Is Worth Its Weight in Gold!”
At Dr. Tom’s Classroom, we have worked hard to make our courses the absolute best preparation for the Mechanical PE Exams. We strive keep our courses as affordable as possible. We know that purchasing a PE Exam prep course is major investment, and we want make sure that your investment pays off with a passing […]
Not a Cold Day on the Sand
The Finns have taken sand and turned it into an energy storage battery. Using insulated holding tanks that are 4 meters in diameter by 7 meters high filled with hundreds of tons of sand, the unit can store 8 MW-hours of heat, when the sand is heated to 500-600°C. The heat is used to keep […]
FEATURED TESTIMONIAL – I took the HVAC & Refrigeration exam and I PASSED!!!!
“I took the HVAC & Refrigeration exam and I PASSED!!!! Your step-by-step course really did make all the difference! This was my third attempt at taking this thing. The first time I took an in-person study course, a lot of theory, not great with the problem practice. The second time I tried to study on […]
Keeping a Smile on the Mona Lisa in Summer’s Heat
The Louvre Museum and all of Paris have experienced one of the hottest summers in memory. Yet, what’s keeping the Mona Lisa and the millions of visitors cool and comfortable is not immediately obvious. A joint venture company named Fraicheur de Paris [literally – “freshness of Paris”] and jointly owned by EDF (France’s largest energy […]
A Battery That Never Goes Dead
The most troublesome problem with wind or solar power systems is the weather. For the energy these systems create there needs to be a way to store the excess energy and then be able to deliver that excess energy precisely when it is needed. One innovative way to store this energy is to use what […]
With DTC – Pay Up Front and Save $100
Everyone loves a bargain, and with our Pay Up Front option, you can save $100. At DTC, we realize that buying a PE Exam prep course is a major commitment in both in time and money, and we work to make sure our courses are the best and the most affordable. “The course was worth […]
