[Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY

Tue Oct 13 12:58:12 PDT 2015

There are so many differences between what's reported in the LS-D and SS-D that I would 
not use this method for anything more than an extremely crude look at the load 
attributable to OA.  In Loads,  all the heat flows are calculated at the reference 
temperature (TLOADS) and counted as Cooling if the net space load that hour is positive or 
Heating if it's negative.  In Systems, these loads are corrected to the actual zone 
temperature and the load from OA and interzone heat transfer added, while solving for the 
zone temperature. If the zone temperature is outside the thermostat deadband, a deficit 
would be considered a heating load and an excess as a cooling  load on the HVAC system.

There's a much better way to get the OA load, but it would take some work, either with a 
User-Function, which unfortunately is not available in DOE-2.2 (although I've heard that 
Expressions could do much the same thing...), or by post-processing hourly outputs. Print 
out an Hourly Report with the following parameters: Outdoor Air Temp (To), Room Air 
Temperature (Trm), Outside Air CFM, and the Zone Load.  Then, use Excel or awk ( my 
favorite :-) :-) ) to calculate the load due to the OA as (Trm-To)*CFM*Cp of air .  This 
can then be compared to the Zone Load, but you'll notice some anomalies  such as during 
the swing season when the OA Load is actually "free cooling".   You'll then have to decide 
how to attribute the OA heat flows to the HVAC loads, which can be tricky.

Various people, including me, Dan Fisher, Jason Glazer, etc., have wandered into this area 
of deriving component loads, and have found that it ultimately raises philosophical 
questions.  :-) :-)

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 205A
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
http://weather.whiteboxtechnologies.com for simulation-ready weather data
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"

On 10/13/2015 9:02 AM, Keith Swartz wrote:
>
> Good point, David. The system report adds more than just ventilation load to the space load.
>
> Keith Swartz, PE | Senior Energy Engineer
>
> *Seventhwave*| *Madison.Chicago.Minneapolis***
>
> 608.210.7123 seventhwave.org
>
> *From:* David Eldridge [mailto:DEldridge at grummanbutkus.com]
> *Sent:* Tuesday, October 13, 2015 10:47 AM
> *To:* Keith Swartz <KSwartz at seventhwave.org>; Mark.Hallman at rwdi.com
> *Subject:* RE: [Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY
>
> I’m not sure if that will exactly give the ventilation loads – the “L” reports are the 
> building space loads, but the “S” reports will include other system effects such as fan 
> heat, reheat, heat gain to the return air, so that the difference might not exactly be a 
> ventilation load, and might be pretty far from an OA-only load.
>
> If there is a preheat coil, you can set up a report to trend that coil’s load if you are 
> after the heating loads. You could trend the cooling coil load as well, but this is a 
> function of economizer operation and outside air temperature as well.
>
> David
>
> __
>
> David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
>
> *Grumman/Butkus Associates*
>
> __
>
> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of 
> *Keith Swartz
> *Sent:* Monday, October 12, 2015 8:55 AM
> *To:* equest-users at lists.onebuilding.org <mailto:equest-users at lists.onebuilding.org>
> *Subject:* Re: [Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY
>
> Mark,
>
> Look at the differences between values in reports LS-D and SS-D. SS-D includes 
> ventilation. LS-D does not. (The first letter “S” stands for “system.” “L” is for 
> “load,” the load in the space.)
>
> Keith Swartz, PE | Senior Energy Engineer
>
> *Seventhwave*| *Madison.Chicago.Minneapolis***
>
> 608.210.7123 seventhwave.org
>
> *From:* Shaun Martin [mailto:smartin at shaunmartinconsulting.com]
> *Sent:* Friday, October 09, 2015 12:13 PM
> *To:* 'Mark Hallman' <Mark.Hallman at rwdi.com <mailto:Mark.Hallman at rwdi.com>>; 'Bishop, 
> Bill' <bbishop at pathfinder-ea.com <mailto:bbishop at pathfinder-ea.com>>; 
> equest-users at lists.onebuilding.org <mailto:equest-users at lists.onebuilding.org>
> *Subject:* Re: [Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY
>
> Hi Mark,
>
> You can use hourly reports to pull out the outside air volume (variable PO) plus the 
> supply and return volumes and temperatures. Then off to a spreadsheet.
>
> Or, if you’re feeling ambitious, you could write an input function (see Topics).
>
> Shaun
>
> Shaun Martin LEED-AP, BEMP
>
> Principal
>
> Shaun Martin Consulting
>
> #90 – 425 Carrall Street
>
> Vancouver, BC V6B 6E3
>
> p. 604-789-1095
>
> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of 
> *Mark Hallman
> *Sent:* Wednesday, October 7, 2015 7:59 PM
> *To:* 'Bishop, Bill' <bbishop at pathfinder-ea.com <mailto:bbishop at pathfinder-ea.com>>; 
> 'equest-users at lists.onebuilding.org' <equest-users at lists.onebuilding.org 
> <mailto:equest-users at lists.onebuilding.org>>
> *Subject:* Re: [Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY
>
> Thanks Bill, nice tip. Any way of parsing it out without running two simulations?
>
> Tx!
> Mark.
>
> *mark hallman*
>
> p.eng. leed ap bd&c
>
> project engineer
>
> mdh at rwdi.com <mailto:mdh at rwdi.com>
>
> 519 823 1311 x2494
>
> RWDI:  the science of buildings, structures & the environment.  See what we do HERE 
> <http://www.rwdi.com/#%21services3/c1h0m>.
>
> *From:*Bishop, Bill [mailto:bbishop at pathfinder-ea.com]
> *Sent:* Wednesday, October 07, 2015 11:12
> *To:* Mark Hallman; 'equest-users at lists.onebuilding.org'
> *Subject:* RE: % LOAD ATTRIBUTED TO OA DELIVERY
>
> One way would be to create a MIN-AIR-SCH with all hourly values set to 0 (or 0.001 to 
> activate economizer), apply it to all SYSTEMs and use the difference in the outputs.
>
> Regards,
>
> ~Bill
>
> *William Bishop, PE, BEMP, BEAP, CEM, LEED AP **|**Pathfinder Engineers & Architects LLP*
>
> *Senior Energy Engineer*
>
> 	
>
> cid:image001.jpg at 01D104F5.971C54D0 cid:image002.jpg at 01D104F5.971C54D0
>
> 134 South Fitzhugh StreetRochester, NY 14608
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> */T: (585) 698-1956/*F: (585) 325-6005
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> bbishop at pathfinder-ea.com <mailto:wbishop at pathfinder-ea.com>www.pathfinder-ea.com 
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> http://png-5.findicons.com/files/icons/977/rrze/720/globe.pngCarbon Fee and Dividend - 
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> *From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of 
> *Mark Hallman
> *Sent:* Wednesday, October 07, 2015 10:59 AM
> *To:* 'equest-users at lists.onebuilding.org' <equest-users at lists.onebuilding.org 
> <mailto:equest-users at lists.onebuilding.org>>
> *Subject:* [Equest-users] % LOAD ATTRIBUTED TO OA DELIVERY
>
> Hi there,
>
> Is there a way to accurately parse out from the eQUEST output file the percentage of the 
> cooling and heating load that is attributed to OA delivery?   Any advice would be 
> appreciated.
>
> Thanks in advance!
> Mark Hallman.
>
> *mark hallman*
>
> p.eng. leed ap bd&c
>
> project engineer
>
> mdh at rwdi.com <mailto:mdh at rwdi.com>
>
> 519 823 1311 x2494
>
> RWDI:  the science of buildings, structures & the environment.  See what we do HERE 
> <http://www.rwdi.com/#%21services3/c1h0m>.
>
>
>
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