Last week in Thermal Storage for Grid-Interactive Efficient Buildings (GEBs), I introduced the importance of phase changes from solid to liquid to vapor, and the reverse, to our modern world. Benefits include heating, cooling, and refrigeration for all types of uses, including space conditioning, food storage and transportation, healthcare, manufacturing, and of course, thermal storage. The simplest everyday thermal storage material is ice. Grocery and convenience companies have enormous ice-making facilities for guess what: thermal storage and your lowly Igloo or swanky Yeti coolers. I have a Coleman Lil Oscar cooler that I’ve used since Ha School. Now that is…
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Aside from efficiency being a core component of my thermos-fluids courses in engineering school, phase changes were also captivating to me. Phase changes from solid (ice) to liquid (water) to vapor (steam) have been used for hundreds of years, and more recently, the last 150 years, give or take, to generate electricity, refrigerate, freeze and keep us cool in the summer heat. Like water, practically anything will freeze, melt or vaporize. Take copper, please. It is widely used to conduct electricity in homes and buildings. It too melts and vaporizes. When it vaporizes, you don’t want to be near it…
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Last week Wisconsin’s Governor Walker pronounced drought emergencies for 40-plus counties in the land of cheese. I’m not sure what that means other than the obvious fact that it is dry and it’s been hotter than bejeezus for quite some time, with the peak being the week of Independence Day. A “blocking” high pressure system was parked in the middle of the country. High pressure systems result in sinking air, the opposite of low pressure systems where surface air rises to cold altitudes causing clouds and rain. Sinking air results in no clouds and heat of compression. Heat of compression…
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We interrupt this rant for this special announcement. Our cold spring in the northern plains is wreaking havoc in the form of tornadoes in the southern and middle parts of the country. I think the weather phenomena had a lot to do with my interest in mechanical engineering. Growing up on the farm in the flatlands, I had seen a great many black clouds approaching on the horizon. As they drew closer, they would either brighten to a lighter gray and rain, or they get ugly. If the approach is led by a dark band of clouds followed by blue-green…
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