Re: [EnergyPlus_Support] Re: Design Day V.S. Schedule

Thank you. I have questions about design day and sizing.

In energyplus, the system will be sized on design day, and shown in hvac sizing summary. It will take the solar information from weather file and use the weather temperature from whatever we input in SizingPeriod:DesignDay, is it right?

When I run the simulation for a full year, and looked at the report, Space Gain Component at cooling peak month, the maximum zone/sys sensible cooling rate [W] happened on July 10th, 07:15, not on my design day July 21th. Since I use school schedule, there is no occupancy on July 10th.

To size the unit, I want to get the maximum cooling load. I feel like if I change my design day to July 10th in sizing period, I may get a larger calculated design load, but, it's not true. When I change it, the cooling load in hvac sizing summary didn't increase.

The value listed in report of space gain components at cooling peak month, are they the maximum number during each month or they are the averaged number again? zone people total hat gain is zero in Jan, Feb, July, Nov, and Dec, which is totally different from my occupancy schedule, I have people in building during these months. How should I understand this report? Thanks a lot.

Qianmin

On Fri, Jul 15, 2011 at 7:46 AM, YuanLu Li <yli006@xxxxxxxxxxx> wrote:

Sorry, I did not sent you any attachments.

The file names meant to be examples to show the Ssz and Zsz.

You would have these files in your simulations runs.

However, I have resent the IDF which has the unused material and construction removed.
The report variable section is different from the skilight version.
======================
It is also not necessary to have completed long schedules with four or more sections.

For sizing, SummerDesignDay is for Cooling set point schedule. WinterDesignDay is for heatingDesignDay set point. All the schedules are for holidays and working days. Only you do want the DesignDays to be in some working days and in some holidays, then you need to list tem in a separated time period. Because, it is for sizing, it should be in the two worst case condition.

If you really wanted to enter a complicated and exact occupancy or usage conditions, you can set up a spread sheed and called it a unique schedule file, with a row for each hour of the year. Each column can be specified for use by rhe relevant schedule object. I am not suggesting that you should do this. However, it is an available EPlus option.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx

Date: Thu, 14 Jul 2011 17:07:51 -0700

Subject: Re: [EnergyPlus_Support] Re: Design Day V.S. Schedule

huh,,I didn't see any attachment.

On Thu, Jul 14, 2011 at 3:52 PM, YuanLu Li <yli006@xxxxxxxxxxx> wrote:

For sizing maximum, there are csv files with sz in the file name.

QMZ_DD_skylightSsz.csv   for system sizing.QMZ_DD_skylightZsz.csv   for zone sizing.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: zqianmin@xxxxxxxxx
Date: Thu, 14 Jul 2011 15:45:34 -0700

Subject: Re: [EnergyPlus_Support] Re: Design Day V.S. Schedule

Oh, got it! So this number is kind of useless to size the hvac system. I didn't realize they are averaged number before. What I want to look at are the number in .csv file. Thank you!
Qianmin

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