What I think is meant is that it's going to take a long time for the interrior of a home to heat up when the sun is beating down on it thru an adboe wall. After the sun sets and the outside temperature drops, the adobe wall will then continue to transfer heat to the interior for several hours due to the time lag effect. Thus a well-planned adobe wall of the appropriate thickness is very effective at controlling inside temperature through the wide daily fluctuations typical of desert climates (ie it wont get as hot or as cold inside as it does outside). As far as that goes, I think I've heard the same "insulation" story when visiting Scotty's Castle in Death Valley. Scotty went one step further by having a cascading waterfall as a feature in one of the interrior walls. --- On Mon, 12/27/10, Kim <kimharch@cut.net> wrote: From: Kim <kimharch@cut.net> Subject: [Utah-astronomy] Straight Dope To: "'Utah Astronomy'" <utah-astronomy@mailman.xmission.com> Date: Monday, December 27, 2010, 11:48 AM For anyone who reads the Salt Lake City Weekly you may have already heard of Cecil Adams and his column, The Straight Dope. For fun this morning I perused his website by the same name. I found this gem from 1986: http://www.straightdope.com/columns/read/417/is-the-great-wall-of-china-the-.... This reminds me of one of my favorite LDS myths (unrelated/off-topic, so don’t anyone get offended, please). As a child I was told how brilliant Brigham Young had been to tell the Utah settlers to build with adobe. It was cheap, and according to LDS myth, “a great insulator.” (This is still being perpetrated by the Blessed Sisters of Temple Square in their tours at Brigham Young’s SLC residence, the Beehive House. Go take a tour if you doubt it. You’ll hear other LDS myths, too.) For anyone who cares, and for the record, adobe is NOT an insulating material at all. It would take a 50-inch-thick adobe wall to approximate the insulation value of a typical 2x6 exterior wall in modern construction. Adobe’s favorable properties as a building material come largely from its thermal mass. I won’t bore everyone with details, but if you’re interested, here’s a good discussion of the thermal properties of adobe: http://www.quentinwilson.com/adobe-as-mass/. FWIW, I live in a house partially built of adobe and my pioneer ancestors built houses of adobe. I am proud of my LDS heritage, even when myths are told about them. Merry belated Christmas to everyone, and Happy New Year. Kim _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com