[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] Re: LEED ID+C EA - Minimum Energy Performance - Type of chiller system 8





So from memory, and it has been quite some time now, the Central Heating and Cooling Water Plants serve the whole building. You can send that water any which way it needs to go. Just like you have one "HVAC" system per floor in the baseline, they are still all supplied by the same water plant.

The exception you claimed seems reasonable, but I guess I don't see the whole picture. The reason behind these exceptions is that you get lots of wasted energy when you spec the system to supply one air temperature for two different spaces with different needs (loads). For example, if you have one system serving server rooms and saunas, you would have to locally reheat all the air to the saunas as the central unit will be supplying cooled air for the servers. It gets even worse as the Outdoor air fraction my be set low for the servers and now you have to over ventilate the saunas to deliver the same fresh air at the reduced ODA fraction.
So in this case differing loads (heating, cooling, ODA, humidity) are also time of day dependant...hence all the exceptions that may apply.

Hope that helps,

Jean


Am 06.09.2017 6:33 nachm. schrieb "vg.terao@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>:
 

Hi Dante,

thank you for your answer.

Our retail is served by the mall HVAC system. We don't have to model the whole mall anyway. Just in the proposed case, we have calculated the cooling capacity using the method 1 (using a surface ratio).

If i follow your explanations, both tables are totaly independent from the real HVAC system, so I should use a power of 8 kW, which give me a single water-cooled screw chiller.

But I am afraid that the USGBC refuse these settings, because we would use performance of a small HVAC system, while the retail take advantage from the performance of important chillers capacities.

Moreover, the fact that the USGBC refused the exception claimed for our choice of the system 4, the use of system 8 should reflect the setups of the whole mall ?

Do you have any idea about that ?

Regards,
Vincent




__._,_.___

Posted by: Jean Marais <jeannieboef@xxxxxxxxx>


EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The EnergyPlus web site is found at:
http://www.energyplus.net/

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the &quot;search&quot; button.




Visit Your Group
Yahoo! Groups
PrivacyUnsubscribeTerms of Use

__,_._,___