[Equest-users] How to get accurate building load component using eQUEST
Joe Huang via Equest-users
equest-users at lists.onebuilding.org
Sun Nov 20 22:30:10 PST 2016
Yongqing is correct. This kind of information is not available in any of the hourly
reports, but it can be calculated although depending on the complexity of the building it
might almost feel like you're writing a small loads calculation program :-)
I worked with a Research Associate (Ellen Franconi, now at the Rocky Mountain Institute)
to do this using FUNCTIONs in DOE-2.1E, but since FUNCTIONS are not invoked in
DOE-2.2/eQUEST, you'd have to write out hourly reports for the LOADS loads for each
exterior surface and then adjust the loads for the difference between the constant LOADS
temperature and the actual zone temperature in SYSTEMS using a simple UA delta T
correction, i.e., Loads Correction = (UA of surface)*(Tsystem - Tloads). You can get the
U-value and area of each surface from the LDS verification report. For infiltration,
instead of a UA use the air volume times its specific heat. Once you've done all this,
you will have the actual heat flows to the building, but these will not correspond to the
SYSTEM Loads because of the temperature deadband. After trying various approaches, Ellen
and I found the best to be aggregating the heat flows when the system is off, and then
dumping it to either heating or cooling depending on the system mode when it starts up
again. Don't expect complete correspondence with the System Load, but generally we were
getting within 5-10%.
This paper_(the first report) describes th_e FUNCTION-based method that Ellen and I
used.__ <cid:part1.EE65E257.20A3318C at whiteboxtechnologies.com>
__Joe__<cid:part1.EE65E257.20A3318C at whiteboxtechnologies.com>
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 11/18/2016 8:14 AM, zhaoyongqing1987 via Equest-users wrote:
> No hourly report can provide these information!
>
> On 11/18/2016 23:48, Shaun Martin <mailto:smartin at shaunmartinconsulting.com> wrote:
>
> Hi,
>
> You'll have to use hourly reports to get at that data. The procedure is fairly well
> laid out in the doe2 manuals and it's under the project tab on the equest screen.
>
> Shaun
>
>
> On Nov 17, 2016 11:58 PM, zhaoyongqing1987 via Equest-users
> <equest-users at lists.onebuilding.org <mailto:equest-users at lists.onebuilding.org>> wrote:
>
>
> Hi,Saurabh
>
> Sorry,maybe I don't make my question clear.
>
> the procedure of the building loads's calculation in eQUEST is shown as following:
>
> 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.(posted by Joe huang)
>
> *And monthly building load components(such as building load from roof,building
> load from wall and building load from window conduction etc.) are listed in LS-F
> report. But all these results in LS-F report are calculated based on the
> reference temperature(TLOADS),which is a fixed value assumed by user,not the
> actual zone temperature.My question is how to get the building components that
> are calculated based on actual zone temperature!*
> *
> *
> *Yongqing*
>
> At 2016-11-18 15:15:42, "Saurabh Kumar Srivastava" <SASV at cowi.com
> <mailto:SASV at cowi.com>> wrote:
>
> Hi Yongqing,
>
> I believe what you're looking for is:
> If you have a room which is conditioned, you would like to know the building
> energy consumption without specifying the Room set-point temperature?
>
> To calculate the Energy consumption a Delta T(temp) value would be required
> by eQuest, so it uses 1 temp from the weather file and other is the set
> point you have defined in the zone.
> Until now I guessit not possible to model Free Cooling/Passive cooling for
> Rooms in a building, where in you let the room achieve various temperature
> when unconditioned and calculate fan power etc. etc.
>
> But the crude way out of all this is you can input various Set point
> temperatures for a room in a given range say from 20°C to 30°C and take a
> median values obtained post simulation and evaluate the building load component.
>
> The software does give hourly outputs for a fixed room set point temperate
> in Report SS-G. Scroll down in the .sim file to see additional hourly data
> for a zone.
>
> Feel free to ask, if any more doubt
>
> Best Regards
>
> *Saurabh
>
> *
>
> *From:*Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
> <mailto:equest-users-bounces at lists.onebuilding.org>] *On Behalf Of
> *zhaoyongqing1987 via Equest-users
> *Sent:* Friday, November 18, 2016 11:22 AM
> *To:* equest-users <equest-users at lists.onebuilding.org
> <mailto:equest-users at lists.onebuilding.org>>
> *Subject:* [Equest-users] How to get accurate building load component using
> eQUEST
>
> Dear eQUEST user,
>
> In eQUEST,LS-F is the building load component report,but the load in this
> report is calculated based on fixed indoor temperature.
>
> And it is not precise.My question is if there is anyway to get the accurate
> building load component,which is calculated based on
>
> hourly changed indoor temperature.
>
> Yongqing
>
>
>
>
>
>
>
>
>
>
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