[Equest-users] App G model VAV w unmet loads in heating

[Matthew Baron]

HI,
I have tried both your suggestions, seemed to help slightly... still very high unmet loads for heating. I have attached the .inp and .pd2 files for inspection.

Thanks,
Matthew J. Baron


Wendel, 140 John James Audubon Pkwy, Suite 201, Buffalo, NY 14228
p 716.688.0766   f 716.625.6825   e mbaron at wendelcompanies. com   w wendelcompanies. com

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-----Original Message-----
From: Daniel Knapp [mailto:danielk at arborus.ca] 
Sent: Tuesday, July 30, 2013 10:44 AM
To: Matthew Baron
Cc: 'equest-users at lists.onebuilding.org'
Subject: Re: [Equest-users] App G model VAV w unmet loads in heating

Hi Matthew,

I have run into this problem myself for buildings in cold climates.  The problem is that the reheat coils are sized to the reheat delta T (defaulting to 30ºF) which usually assumes a supply air temperature of 55ºF maybe resetting to 65ºF in heating mode.  However, in winter, the supply air temperature can dip quite a bit lower than this (down to 30ºF or lower) unless you have a central heating coil.  The DOE keyword is HEAT-SET-T and it's worth checking the .inp file to make sure this keyword is set.  In eQuest you need to set the "Hot Deck Max Leaving Temperature" (maybe to 65ºF) to activate HEAT-SET-T.  You might also try setting COOL-CONTROL = WARMEST to reset the supply air temperature upward as loads permit and increase the "Reheat Delta T" to 40ºF. 

If this doesn't work, send your .pd2 and .inp up the list and maybe someone can have a quick look at the file.

All the best,
Dan 

-
Daniel Knapp, PhD, P Phys, LEED® AP O+M
danielk at arborus.ca

Arborus Consulting
Energy Strategies for the Built Environment www.arborus.ca
76 Chamberlain Avenue
Ottawa, ON, K1S 1V9
Phone: (613) 234-7178 ext. 113
Fax: (613) 234-0740




On 2013-07-30, at 9:03 AM, Matthew Baron <mbaron at wendelcompanies.com> wrote:

> HI,
> I am working on several school models and they generally fall into the packaged vav with reheat category. The spaces are fine for cooling, but are way off for heating. When I look at the ss-p report the heating capacity for the units shown to be zero, when I look at the ss-a report it indicates the heating load. I have entered the hot deck temp, zone entering temp, a preheat coil. Any suggestions would be appreciated.
>  
> Thanks,
> Matthew J. Baron
> <image002.png>
> 
> Wendel, 140 John James Audubon Pkwy, Suite 201, Buffalo, NY 14228
> p 716.688.0766   f 716.625.6825   e mbaron at wendelcompanies. com   w wendelcompanies. com
> 
> ARCHITECTURE    ENGINEERING    PLANNING    ENERGY SERVICES    CONSTRUCTION MANAGEMENT
> 
> CONFIDENTIALITY NOTICE: This email transmission is confidential and is intended only for the person(s) named above. Its contents may also be protected by privilege, and all rights to privilege are expressly claimed and not waived.  If you have received this email in error, please call us immediately and destroy the entire email. If this email is not intended for you, any reading, distribution, copying or disclosure of this email is strictly prohibited.
> 
> Please consider the environment before printing this email.
>  
> <ss-p.pdf><ss-a.pdf>_______________________________________________
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