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34
<br />Systems Eliminated
<br />Several systems were eliminated from further consideration. Because of higher energy and
<br />maintenance costs, and the inability to meet necessary indoor air quality standards, the
<br />PTAC and DX systems were eliminated from consideration. The WSHP and unit
<br />ventilator/fan coil systems were eliminated ,due to their inability to adequately satisfy all
<br />indoor air quality requirements, particularly in small, compartmentalized rooms. Thus, our "
<br />~shortlist" of considered systems was reduced to the multi-zone and variable volume systems
<br />for each building.
<br />Recommendations
<br />Whiffed Building
<br />For the existing building construction and use, we calculated a maximum cooling load
<br />requirement of approximately 200 tons (Tons is a unit of measurement for determining
<br />cooling capacity. One ton equals 12,000 Btuh). For either amulti-zone or VAV system, the
<br />cooling source will be an air-cooled chiller; the air-cooled chiller will provide chilled water at a
<br />similar overall system efficiency as awater-cooled. system, while reducing component
<br />numbers and- maintenance ,cast. With natural gas readily available, the heating source will
<br />be two (2) natural gas-fired hot water boilers.
<br />A comparison of the two proposed systems is as follows:
<br />.System ° r~PGbahle : ; Energy imple l~niform -. , :Median `-
<br />,, pesCriptiOn Construction~:~ Costs Payback, Annual Cost ' Useful
<br />
<br />,;
<br />,..' '
<br />Cost ($)
<br />($)/year.
<br />years
<br />; ($) ' S stem.L~fe.
<br />y
<br />k
<br />4
<br />i:~
<br />~fy?`! /.~.,
<br />~~.lal wl
<br />Multi-zone, Air-
<br />cooled chiller
<br />and natural gas $1,204,900 $60,900 N/A $105,800 20
<br />boiler
<br />1lA ,,;per cr5~fe~ ' ~. s s- ~' S t j f ~ ~ ~ ~ , "
<br />:ch~~l~1~.andl+y~{~Y"Y1
<br />`
<br />a
<br />ural#
<br />~ •.~ 1'~;.~ r' ",'ii
<br />..
<br />~4 ~~.i i ~. '
<br />'
<br />, •: ,4
<br />,
<br />~ jl. ;.~~4 ~1. ~~~i
<br />;G:; ,~tr~~~~~ 4
<br />;' r ~ ' jai
<br />~~ ~ ~ .x ''~,,,~
<br />r, . ;L
<br />~
<br />~ ~
<br />n
<br />t
<br />gas
<br />~„r., ~ ~
<br />,~
<br />' ~
<br />~ r .
<br />~' ;$;11;`309,200 ~
<br />,
<br />r ;
<br />.~:
<br />~... y ~r~ .8r~":
<br />~ r ~~'~9r3~ ~ ~
<br />~ ~,
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<br />.
<br />r
<br />boiler ,. ~:~ ~ , • ,-
<br />,,~ ;
<br />~'Recommer?dedY$ sta , .p~ ~ - ~,
<br />We recommend the insfallation of a variable ar'r volume system with terminal reheat for
<br />the Whined Building based an uniform annual cost. Coaling source will be an air
<br />cooled water chiller to replace the exisfing water-cooled unit.
<br />(34)
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