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John<br>
At Cornell , we have just within the last year installed meters in about
5 zones. The cleanroom is basically two zones, and one zone for
each other floor and to one other major user. And we have a total
flow meter. We will soon begin charging by the meters, with the use
on each floor prorated out by floor to the users. So a room on the
third floor may pay more than a room on the 2nd floor, depending on use
of neighbors. Metering individual rooms is not practical.<br><br>
there are some difficulties however. Average flows are a ctually
pretty steady, even instantaneous flows dont vary much. But the level of
use in the zones is dramatically different so the meters have to be
drastically different sizes. Each meter only works well
over a limited range of flows, and the errors and
offsets are not small.....to the point where the errors and offsets
of the big flowmeters are larger than the flows of the little
meters. So the zone flows never add up to the total
flow....Typically off by 10%. Not to bad except that that 10%
respresents most of the flow to the rest of the
building. So , we get a ballpark reading of the
percentages to each zone, I would not call it an accurate
measurement. And 10% of 200K/yr is real money.
<br><br>
Good luck<br><br>
<br><br>
<br><br>
<x-sigsep><p></x-sigsep>
**************************************************************<br>
Dr. Lynn
Rathbun
<x-tab> </x-tab>Rathbun@cnf.cornell.edu<br>
NNIN Program
Manager<x-tab> </x-tab><x-tab>
</x-tab><x-tab>
</x-tab>(607)-254-4872<br>
CNF Laboratory
Manager
<br>
Duffield
Hall
(607)-255-8601 Fax<br>
Cornell
University
(607)-592-1549 Work Cell<br>
Ithaca, New York
14853<x-tab> </x-tab>
(607)-342-1880 Personal Cell<br><br>
<br><br>
<br>
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