[Equest-users] Heat Rejection consumption is so small!!

[Pasha Korber-Gonzalez]

Hi Omar,

here are my thoughts based on your questions and info.

First, when I read the condenser/heat rejection baseline requirements from
90.1-2007 I interpret that it is not indicating two separate condenser
loops, it is stating "individual condenser loop pumps per chiller", there
for you would still have one condenser circulation loop serving both
chillers and one cooling tower.

Next, if you have heard from designers with experience in the Lebanon
climate characteristics that your heat rejection energy should be upwards of
10% then you could/should trust thier given experience.  However; you need
to ask them what is this 10% relative too?   Are they implying that 10% of
the whole building end use energy should be around 10% for the Lebanon
climate?   (my opinion:  I doubt it.)   Are they implying that 10% of the
Chilled Water System end use energy (i.e. CHW-chiller, CHW-pumps,
CHW-condenser water systems including pumps & tower, etc?)   (my opinion:  I
would guess that this 10% value is relative to HVAC system(s) end use
energy, not *whole building* end use energy.  Or is that 10% relative only
to the chilled water-side of the systems (extracted from the total HVAC
energy which would include heating energy.)

Last,  if you would like to attach your .pd2 & .inp file myself, or maybe
others might be available to peruse your project file and give you some
indication if your end use heat rejection energy is falling within a
reasonable whole building energy range.

p.s.  if you are using a unique (non-eQuest) Lebanon climate weather file,
please attach that too so that I can run your file on my computer.

pkg

On Thu, Jul 15, 2010 at 4:54 AM, Omar Katanani <omar at ecoconsulting.net>wrote:

>
>
> Dear all,
>
>
>
> What are typical values for heat rejection, if my Space Cooling constitutes
> 25% of my school consumption? All I’m getting is 1% or so!
>
>
>
> I left eQUEST to autosize the capacity of the tower, and I entered many
> default values into the inputs of the Open Tower and the Condenser Loop.
> I’ve heard that Heat Rejection in such climates such as Lebanon should
> reach at least 10%.
>
>
>
> One more thing, when modeling the baseline case according to ASHRAE 90.1, I
> read that I should model a condenser water loop for each chiller. So if I
> have 2 chillers, will I need 2 Open Towers?
>
>
>
> Many thanks,
>
> Omar
>
> ___________________________
>
> Omar Katanani
> Sustainable Design Engineer
>
> Email: omar at ecoconsulting.net
>
>
>
> EcoConsulting (Lebanon)
>
> Nahas Building, 4th floor
>
> 4 St-Maron Street / Georges Haddad Avenue
>
> Postal Code: 2028 5806 SAIFI
>
> Beirut, Lebanon
>
> Tel:          +961 (0) 1 971 255
> Mobile:    +961 (0) 3 045 045
>
>
>
> EcoConsulting (UK) Ltd
> 28 Marshalsea Road
> London, SE1 1HF
> Tel:  +44 (0) 207 939 0989
> Fax:  +44 (0) 207 939 0981
>
> Website: www.ecoconsulting.net
>
>
>
>
>
>
>
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