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Posted by kool on July 14, 2007, 12:39 am
>
>> wrote:
>>
>> >
>> >> wrote:
>> >>
>> >>> I have been asked to arrange a quote to cool only an existing
>> >>> building
>> >>>(arena with bowl type seating) for summer use as now the conditions
>> >>>are
>> >>>unbearable during events.
>> >>>
>> >>>I am thinking that 4 BIG units might be the way to go,one in each
> corner,
>> >>>probably splits.
>> >>>
>> >>>I can't seem to find a design condition chart from ashrae or anyone
> else
>> >>>on
>> >>>google. It is a fairly moderate year round climate here, from memory I
>> >>>think
>> >>>we're talking around 80f summer but it hit the mid 90's two days
> ago.Just
>> >>>the people load would be 125 tons and 45,000 cfm o/air required..As
> this
>> >>>will be a major financial investment, I need to do it right the first
> time
>> >>>and any input on design considerations would be appreciated. Thanks.
>> >>>
>> >>>Victoria B.C.
>> >>>
>> >>> Indoor Conditions;24 C/75 F @ 50% RH
>> >>>
>> >>>Design Conditions; ?
>> >>>
>> >>> Occupancy load; 3000x500=1,500,000 btu
>> >>>
>> >>> Square footage;280'x165'= 46,200
>> >>>
>> >>> Cubic footage; 280'x165'= 46,200x48=2,217,600
>> >>>
>> >>
>> >> Based on the information given ;
>> >>
>> >> You've never done this kind of job before
>> >
>> >right
>> >
>> >> You don't feel at all confident now
>> >
>> >wrong
>> >
>> >> You don't know how to provide complete information
>> >
>> >wrong
>> >>
>> >> Therefore, you don't understand what to look for in this
>> >> specialized kind of application.
>> >
>> >wrong
>> >
>> > You haven't mentioned solar load,
>> >
>> >true (although most events are in the evenings)
>>
>> There's some of the incomplete information I mentioned. Plus
>> building load other than occupancy gain, IOW standard load calcs.
>>
>> >
>> >> pre-cooling, indoor design temps ( which at not going to be 'standard
>> >> indoor design' like for a house )
>> >
>> >75F @50%RH (see original post)
>>
>> That is a VERY aggressive ( cold ) target for public events
>> where people are coming in from the warmer outside. IMO.
>>
>> Pre-cooling will be a LARGE factor in your design, if you do
>> it right. Off the top of my head, you should be able to plan on maybe
>> 10 degree rise during events, which means you can pre-cool to 70,
>> expect it to rise to 80 during a 4 hour event, which means you can do
>> the pre-cooling in 4- 8 + unoccupied hours, which means your max size
>> is much smaller.
>>
>> >
>> >other internal loads ( lights, which
>> >> are massive, concessionary equipment ) etc, outdoor air requirement (
>> >> which is a MASSIVE part of your load )
>> >
>> >45,000cfm (see original post again)
>>
>> OK, you did say that.
>>
>> >Hell, I've only spent 15 minutes on this so far.
>>
>> Hell, so have I :-)
>>
>> >
>> >, smoke / fire dampers and
>> >> control, etc etc etc
>> >
>> >Of course, all equipment will be compliant to all codes as this is a
> public
>> >building
>>
>> My point being, smoke exhaust CFM specs will be a guiding
>> factor in fan selection, as well as SOO.
>>
>> >>
>> >> Which add up to :
>> >>
>> >> You lack the knowledge to handle this job by yourself, and you
>> >> need to tell your boss you need more experienced help.
>> >
>> >Paul, I only asked if there are design condition tables available on the
>> >net. This is all very preliminary.I also asked for any input as I will
>> >be
>> >soliciting quotes but we need to tell contracters what we would like
>> >them
> to
>>
>>
>> Well, I don't know what kind of 'design condition tables'
>> someone in the field would need.
>>
>> The BIN tables for your location can be found anywhere, you
>> indoor design target is a decision to be made, and eveything else will
>> be specific to your structure. You're ~ 24 winter design, 75 summer
>> design there.
>>
>>
> http://www.bcpassport.com/vancouver-vital-information/vancouver-climate-temp
> urature.aspx
>>
>> Actually, it looks like you could just open a window :-)
>>
>> Seriously, though look intently at massive use of OA, instead
>> of purely contained conditioned air, in that location. It looks like
>> you could largely get by with a LOT less mechanical than you would
>> need elsewhere if you keep your exchanges up.
>>
>> >quote on. As far as input from you, I have read your resume and I know
> you
>> >can do better than that if you want to.
>>
>> Yeh, and I could get paid more, too :-)
>>
>>
>
> + 85 deg evenings are actually pretty rare, evening sea air at Victoria.
>
> Try and keep the structure quite dry beforehand...later bring in fresh air
> and only in the worst case actually do refrigerate it.
>
> In that case mitigate with fresh or seawater exchange--Ideal bufer maybe
> an
> olympic sized pool.
>
I like the way you think, outside the box. Maybe an ammonia to brine to
glycol heat exchange with chilled glycol loop at 42 degrees would do the
job.We already have 3 pools but being on 108 acres, this building is a long
way from the pools.
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