X-Message-Number: 2200
Date: Mon, 3 May 93 13:17:37 CDT
From: Brian Wowk <>
Subject: CRYONICS Cost Analysis
Robert Ettinger:
> At some point, depending on the answers to several other questions,
> the proposed not-so-cold room might be desirable just on the basis
> of reduced maintenance cost. In the short to intermediate term,
> however, such storage will be more expensive, not less. Cryonics
> Institute research should tell us, fairly soon, just how much more
> expensive it might be.
With all due respect, I do not believe that storage in
stratified LN2 vapor is a good model by which to judge the costs of
-130'C storage. As Professor Ettinger is aware, we have for some
weeks now been refining a design for a mechanically refrigerated Cold
Room (with LN2 backup capability) in this very forum. Although the
capacity of this system is large (100 patients), its economics are so
favorable that any cryonics organization suspending five or more
patients per year could justify building it.
I'm not really ready to do this, but I'm going to do it
anyway. What follows is a very preliminary analysis of Cold Room
costs as I see them.
Let me begin by saying that I've changed my mind about the
refrigeration system. Instead of two P-550 cryocoolers ($12,500 each)
running simultaneously, I now advocate purchasing two P-660
cryocoolers ($16,000 each) to each run at 50% duty cycle. A single
P-660 consuming 5.7kW should have enough muscle to hold the room at
-130'C, and the extra unit gives me a big margin for error in my heat
flow calculations. It also means we won't melt propanol ballast if
one unit fails.
Cold Room Costs (100 patient capacity)
--------------------------------------
Capital Costs:
Two Polycold P-660 Cryocoolers $32,000
Underground water cooling system $20,000
Heat Exchange Hardware
(including fans and defrost elements) $20,000
Foam Insulation $40,000
Interior Structure (wood and aluminum) $10,000
Ballast (400 20 gallon barrels $10,000
and 5000 liters of n-propanol)
Thermocouple Monitoring System $10,000
Fudge Factor (engineering consulting?) $8,000
-----------
$150,000
Annual Operating Costs:
6 kW of electricity at $0.08 per kilowatt hour $4,200
Custodial Labor $800 (?)
------
$5,000
Comments:
At the request of a foam supplier, I am preparing a moderately
detailed project description for their engineers to evaluate
and quote on. On a bulk purchase like this, I expect I'll end
up doing better than the $40,000 retail price above.
The costs of the "heat exchanage hardware" and water cooling
system are I believe high-end estimates for what a metal
working shop would charge to custom build designs I am working
on.
I am not including the costs of the concrete walls surrounding
the Cold Room since a vault needs to be built for whole body
patients anyway. I am not including floor space charges for
the same reason.
Labor costs are a big uncertainty in the above estimates. I
(in consultation with others) can supply a detailed design,
but it is unclear clear to me at this point who would do the
physical labor, who would oversee it, and how much this would
cost. I am very interested in hearing comments on this
subject. Could we, for example, hire a commercial engineering
firm as a general contractor? Would they have enough
expertise and attention to detail to worry about things like
how to install cryogenic foam properly?
Bigfoot Dewar Costs (4 patient capacity)
----------------------------------------
Capital Cost: $18,000 (according to CRFT "Blue Book")
Annual Operating Costs:
5100 liters of LN2 at $0.30 per liter $1,500 (approx)
Custodial Labor $500
-----
$2,000
Cold Room versus Bigfoot
------------------------
A total annual operating cost will be computed by adding
amortized capital costs to the operating costs shown above. Capital
costs will be amortized over 15 years by just dividing by 15.
Interest charges are being ignored since the Patient Care Fund is
currently invested in money market instruments that historically show
a zero real rate of return. The cryocooler costs are being amortized
over 15 years along with the rest of the capital expense since this
approximately equals the manufacturer's stated life expectancy for a
cryocooler running at a 50% duty cylce.
Cold Room Total Annual Operating Cost: $15,000
Bigfoot Total Annual Operating Cost: $3,200
The 100 patient Cold Room can thus be operated for the cost of
about of 5 Bigfoots. Since your 5th Bigfoot will come online when you
suspend your 17th patient, you only need to suspend 17 patients after
you build your Cold Room to break even with Bigfoot storage. Your
savings accrue dramatically after that point.
Consider the situation ten years from now when you have
100 patients in storage. Every year you could be paying:
Cold Room Total Annual Operating Cost: $15,000
or
25 x Bigfoot Total Annual Operating Cost: $80,000
Which storage system would you rather maintain for a hundred years?
It is by no means "premature" to build a Cold Room. With
Alcor less than 20 patients away from breakeven, the time to build a
Cold Room is NOW. Waiting another five or ten years will leave us
swimming in a sea of LOX-contaminated LN2 and red ink.
--- Brian Wowk
Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=2200