X-Message-Number: 1951 Date: Sat, 13 Mar 93 13:43:00 CST From: Brian Wowk <> Subject: CRYONICS Cold Storage Charles Platt: > Seems to me there is one little practical factor which you > omitted from your otherwise very elegant formula re heat > insulation: the cost per square foot per year of floor space. > Here in New York City, we consider $10 per > square foot per year to be low cost for commercial space. 10$ per square foot per year? We better not store patients in New York! The Cost of Cryonics appendix in Alcor's blue book budgets $0.45 (45 cents) per square foot per year. > My math/physics is so ancient and unused, I'm unqualified to > comment on the more technical aspects. It does seem to me, > though, that Ralph Merkle has a point, which can be > summarized as follows: > 1. We DO NOT yet know how to freeze someone without causing > damage on the cellular level. > 2. Therefore nanotechnology will DEFINITELY be required to > revive any patients frozen with current techniques. > 3. Nanotechnology would have an easier job fixing big > fractures than little cells. > 4. Therefore we should devote limited resources to devising > better ways of protecting cells before even thinking about > different preservation systems which may eliminate cracking > but will take time and money to devise and build. > Am I missing something obvious, here? Yes, the possibility that -130'C storage in the room that Mike is proposing might be *cheaper* and *safer* than dewar storage. Alcor's most efficient storage system is currently the Bigfoot dewar. A Bigfoot dewar costs $18,000 and stores 4 patients, boiling off 13 liters of LN2 a day (3 liters per patient). If the vacuum ever fails in one of these beasts, you must immediately transfer 4 patients elsewhere (by no means a simple task). For the capital cost of just two Bigfoots (including a $10,000 allowance for cryosuits) we could build a 200 square foot room able to store 20 patients at -130'C. With two meters of foam insulation, the room would bioloff 70 liters of LN2 a day (3 liters per patient-- same as the Bigfoot). Even if the capital cost is twice as high as I estimate (which it may be if we include R&D as part of the capital cost of the first unit) we will still have a system able to storage patients more cost effectively than Bigfoots. In fact, Alcor is currently storing many patients in dewars which are *less efficient* than Bigfoots. As to my recommendations for outrageously thick insulation, they were based on an LN2 cost of 10 cents per liter. Alcor's blue book actually quotes 25 cents per liter. If this figure is closer to the mark, then as much as 3 meters (!!!) of insulation is indicated (which I knew even fewer people would take seriously). --- Brian Wowk Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1951