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Re: [EnergyPlus_Support] Re: Lots of Warnings

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Re: Lots of Warnings
From: "Michael J. Witte" <mjwitte@xxxxxxxx>
Date: Tue, 19 Jul 2005 16:50:29 -0500
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The return air node.

On 9 Jul 2005, at 20:58, Ali_Ajmi wrote:

> Mike what node is representing the outlet zone after its effected by the people
> presence.
> 
> Regarads
> Ali
> 
> "Michael J. Witte" <mjwitte@xxxxxxxx> wrote:
> There are two things which can change the humidity ratio in a zone: 
> infiltration and internal latent loads (assuming you are not using EMPD or MTF
> moisture capacitance modeling). Turn on report variables to see if there are any
> latent internal gains present (from PEOPLE or equipment) and to see if the
> infiltration flow rate is significant compared to the HVAC system flow rate.
> 
> Mike
> 
> 
> On 7 Jul 2005, at 16:39, Ali_Ajmi wrote:
> 
> > Thanks Mike, I am really appreciate your help even though you are in a
> > Holiday. Mike, I changed the VAV damper action to be reverse based on your
> > advice, the outputs now more reasonable, however, the humidity ratios are not
> > changing between inlet and outlet zones nodes!! Please, could you help me I am
> > really running out of time. Excel file for the nodes value is attached.
> > 
> > Regards
> > Ali
> > 
> > 
> > "Michael J. Witte" wrote:
> > The system appears to be operating as specified. From the Input Output 
> > Reference for SET POINT MANAGER:MIXED AIR:
> > 
> > "Consequently the mixed air temperature set point must take into account any
> > downstream system fan heat if it is to meet a desired system supply air
> > leaving temperature. The Mixed Air Set Point Manager accomplishes this by
> > referencing a supply air set point set by another set point manager (most
> > likely at the primary air system exit node). The supply fan inlet and exit
> > nodes are also inputs to the Mixed Air Set Point Manager. From this
> > information the Mixed Air Set Point Manager calculates the supply fan air
> > temperature rise, subtracts it from the reference set point temperature and
> > uses the result as the mixed air node set point temperature." 
> > 
> > VAV SYS 1 OUTLET NODE:System Node Temp[C](Each Call) is 18C when the main
> > heating coil is scheduled on. The temperature leaving the heating coil is
> > 17.04C and the fan heat raises the supply temperature to 18C. 
> > 
> > For the east and west zone, the reheat coils are running at or near full on,
> > and the VAV dampers are at minimum flow, so the resulting supply temperature
> > is very high. This indicates that the VAV damper heating action should be set
> > to REVERSE ACTION or these zones need baseboard heat to supplement the VAV
> > system.
> > 
> > Mike
> > 
> > 
> > On 1 Jul 2005, at 17:19, Ali_Ajmi wrote:
> > 
> > > I have changed the preheat set preheat design set temperature to 18 C still
> > > the out put data is look nonsense in the heating season, csv attached. Inlet
> > > temperature is very high 115 C VAV Sys 1 outlet node always less or equal
> > > 18C Could you help me sort out this problem. Please, could you also
> > > elaborate what does you mean in this paragraph 'The SET POINT MANAGER:MIXED
> > > AIR pushes this setpoint to the heating coil exit (less the fan heat delta),
> > > but the heating coil appears to be unable to meet the load at some times'
> > > 
> > > Regards
> > > Ali
> > > "Michael J. Witte" wrote:
> > > The SET POINT MANAGER:WARMEST object is setting the supply air temperature
> > > setpoint. It has an upper limit of 18C. So, if no zones require cooling, it
> > > will max out at 18C.
> > > 
> > > The SET POINT MANAGER:MIXED AIR pushes this setpoint to the heating coil
> > > exit (less the fan heat delta), but the heating coil appears to be unable to
> > > meet the load at some times. Try setting the "Preheat design set
> > > temperature" in the SYSTEM SIZING object to 18C.
> > > 
> > > Mike
> > > 
> > > p.s. I'm gone tomorrow for a 4-day weekend. If you have questions tomorrow,
> > > please send to the yahoo group or to energyplus-support@xxxxxxxx
> > > 
> > > 
> > > On 30 Jun 2005, at 22:22, Ali_Ajmi wrote:
> > > 
> > > > Thanks Mike yes I was confused between the node names. Mike I checked the
> > > > csv output file every things was reasonable in the cooling design day,
> > > > however, is not in the heating mode; for example: VAV Sys outlet Node:
> > > > System Node Temp[C] = 14.46 C VAV Sys outlet Node Setpoint Temp[C] = 18 C
> > > > Mixed Air temp = 4.89 C
> > > > 
> > > > Is the reason heating design setpoint temp. assigned to18 C?
> > > > 
> > > > Attached with a CSV of the file you send me for your quick reference.
> > > > 
> > > > Regards
> > > > Ali
> > > > 
> > > > "Michael J. Witte" wrote:
> > > > 
> > > > My csv output file does not look like that. Are you sure you are not
> > > > confusing several very similar node names. The only way that a given
> > > > keyname+reportvariable combination can appear more than once in a csv file
> > > > is if one is if the same thing is reported with and without schedule or at
> > > > a different reporting frequency.
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > On 29 Jun 2005, at 17:24, Ali_Ajmi wrote:
> > > > 
> > > > > Thanks Mike for sending me the file. Mike I have looked it and generate
> > > > > a run, the out put seems reasonable, however, I have some inexplicable
> > > > > out puts data. These are as follows: 1) Zone North in Node: System node
> > > > > Temp [C] has two values in two different columns in the out puts; 15 C
> > > > > and 35 C. 2) Zone North Node: System node setpoint Temp[C] has two
> > > > > values, -999 and 25 C.
> > > > > 
> > > > > Please could advice me what may the reasons.
> > > > > 
> > > > > Regards
> > > > > Ali
> > > > > 
> > > > > "Michael J. Witte" wrote:
> > > > > I passed it along to another team member but I haven't heard back. My
> > > > > file without return fan shows loads. See attached.
> > > > > 
> > > > > Mike
> > > > > 
> > > > > 
> > > > > On 23 Jun 2005, at 16:55, Ali_Ajmi wrote:
> > > > > 
> > > > > > "Michael J. Witte" wrote:
> > > > > > Not sure if there's a problem with the way the return fan is described
> > > > > > or if it's a programming problem.
> > > > > > 
> > > > > > Mike I deleted the return fan, every things went smooth. However, the
> > > > > > sensible heating/cooling of the zones were Zeros. Have you checked if
> > > > > > the progarm, E+, has problem with return fan? 
> > > > > > 
> > > > > > Thanks
> > > > > > Ali
> > > > > > 
> > > > > > 
> > > > > > Tried one more thing - deleted the return fan and the errors went
> > > > > > away. Not sure if there's a problem with the way the return fan is
> > > > > > described or if it's a programming problem.
> > > > > > 
> > > > > > Mike
> > > > > > 
> > > > > > 
> > > > > > ------- Forwarded message follows -------
> > > > > > From: Michael J. Witte 
> > > > > > To: ajmi70kw@xxxxxxxxxxx
> > > > > > Subject: Re: Lots of Warnings
> > > > > > Date sent: Thu, 9 Jun 2005 16:43:47 -0500
> > > > > > 
> > > > > > For some reason, the air loop components are fighting over whether
> > > > > > there is flow in the system at certain times, which is causing some
> > > > > > iterations to evalute the coil at a very low airflow rate which causes
> > > > > > the errors. I will have to ask someone else to look at this to figure
> > > > > > out if it's an input problem or not. Ultimately, I think the final
> > > > > > results are OK, just some of the early iterations are confused.
> > > > > > 
> > > > > > Mike
> > > > > > 
> > > > > > 
> > > > > > On 7 Jun 2005, at 10:56, Ali_Ajmi wrote:
> > > > > > 
> > > > > > > Dear Mike,
> > > > > > > I am still struggling to sort out my IDF file
> > > > > > > (VAVEnvlopBuild_fivZone1.idf). I have implemented your advices where
> > > > > > > I changed the set point manger to Warmest, however, when I tried to
> > > > > > > use the Coldest set point manger the file is crashed. Also I have
> > > > > > > changed the time step in average window to be 1.4. Then I imitate
> > > > > > > the 5ZoneAutoDXVAV.idf in the example files folder to be sure that
> > > > > > > both IDFs are almost similar. However, still i have lots of
> > > > > > > warnings, about 20,000. Please could have a look to the file
> > > > > > > (attached). Mike could you kindly treat this problem as urgent
> > > > > > > because I am ruining out of time to implement my PhD research
> > > > > > > experiments.
> > > > > > > 
> > > > > > > File will be uploaded at the submitals_problem folder. I am using
> > > > > > > now E+1.2.2. Regards Ali 
> > > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > ---------------------------------
> > > > > > > Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with
> > > > > > > voicemail
> > > > > > 
> > > > > > 
> > > > > > ------- End of forwarded message -------
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > ---------------------------------
> > > > > > Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with
> > > > > > voicemail
> > > > > 
> > > > > 
> > > > > 
> > > > > ========================================================
> > > > > Michael J. Witte, GARD Analytics, Inc.
> > > > > EnergyPlus Testing and Support 
> > > > > EnergyPlus-Support@xxxxxxxx
> > > > > 
> > > > > 
> > > > > 
> > > > > ---------------------------------
> > > > > Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with
> > > > > voicemail
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ---------------------------------
> > > > Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with
> > > > voicemail
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > ---------------------------------
> > > How much free photo storage do you get? Store your holiday snaps for FREE
> > > with Yahoo! Photos. Get Yahoo! Photos
> > > 
> > > [Non-text portions of this message have been removed]
> > > 
> > > 
> > > 
> > > The primary EnergyPlus web site is found at:
> > > http://www.energyplus.gov
> > > 
> > > The group web site is:
> > > http://groups.yahoo.com/group/EnergyPlus_Support/
> > > 
> > > Attachments are not allowed -- please post any files to the appropriate
> > > folder in the Files area of the Support Web Site.
> > > 
> > > Yahoo! Groups Links
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > 
> > 
> > 
> > ========================================================
> > Michael J. Witte, GARD Analytics, Inc.
> > EnergyPlus Testing and Support 
> > EnergyPlus-Support@xxxxxxxx
> > 
> > 
> > 
> > 
> > The primary EnergyPlus web site is found at:
> > http://www.energyplus.gov
> > 
> > The group web site is:
> > http://groups.yahoo.com/group/EnergyPlus_Support/
> > 
> > Attachments are not allowed -- please post any files to the appropriate folder
> > in the Files area of the Support Web Site.
> > 
> > Yahoo! Groups Links
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > ---------------------------------
> > Yahoo! Messenger NEW - crystal clear PC to PCcalling worldwide with voicemail
> > 
> > [Non-text portions of this message have been removed]
> > 
> > 
> > 
> > The primary EnergyPlus web site is found at:
> > http://www.energyplus.gov
> > 
> > The group web site is:
> > http://groups.yahoo.com/group/EnergyPlus_Support/
> > 
> > Attachments are not allowed -- please post any files to the appropriate folder
> > in the Files area of the Support Web Site.
> > 
> > Yahoo! Groups Links
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> 
> 
> ========================================================
> Michael J. Witte, GARD Analytics, Inc.
> EnergyPlus Testing and Support 
> EnergyPlus-Support@xxxxxxxx
> 
> 
> 
> 
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
> 
> The group web site is:
> http://groups.yahoo.com/group/EnergyPlus_Support/
> 
> Attachments are not allowed -- please post any files to the appropriate folder
> in the Files area of the Support Web Site.
> 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> ---------------------------------
> How much free photo storage do you get? Store your holiday snaps for FREE with
> Yahoo! Photos. Get Yahoo! Photos
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
> 
> The group web site is:
> http://groups.yahoo.com/group/EnergyPlus_Support/
> 
> Attachments are not allowed -- please post any files to the appropriate folder
> in the Files area of the Support Web Site.
> 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> 
> 






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References:
- Re: [EnergyPlus_Support] Re: Lots of Warnings
  - From: Michael J. Witte
- Re: [EnergyPlus_Support] Re: Lots of Warnings
  - From: Ali_Ajmi

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