[Equest-users] VRF/VRV PowerPoint on Modeling

Paul Diglio paul.diglio at sbcglobal.net
Sat Jan 22 17:03:18 PST 2011


Gregory:

Yes, I have encountered the scenario you mentioned in item 3 below. It seems on 
occasion, eQuest is reporting VRV heating energy as cooling.  I had a model 
where I created multiple hourly report blocks to verify that the spaces were not 
above set-point in the winter when the simulation file was reporting heat pump 
cooling energy use, which actually was heat pump heating energy use.

Might be the problem is that we are modeling the VRV system as PVVT systems, 
which they are not.

I have created custom curves for the Daikin VRV system, and it reduced energy 
usage about 3% below the standard eQuest heat pump curves.  This is in addition 
to the spreadsheet analysis of the simulation heat-cool energy as outlined in 
the BSUG slide presentation of April 15, 2009.

Paul Diglio






________________________________
From: Gregory Raffio <graffio at gosustainableenergy.com>
To: Carol Gardner <cmg750 at gmail.com>
Cc: Paul Diglio <paul.diglio at sbcglobal.net>; equest-users at lists.onebuilding.org
Sent: Sat, January 22, 2011 6:51:34 PM
Subject: Re: [Equest-users] VRF/VRV PowerPoint on Modeling

Sorry, Carol, but I think we're on different pages. That's fine, its really easy 
for Q&A to misfire via e-mail. Its very likely that my original question set was 
a bit too scattered.

Let me try to simplify 
	* Using the hourly report methodology from the presentation, we obtained the 
electricity use for space cooling and space heating for the entire building, and 
each individual system.
	* eQuest outputs many standard reports such as "Monthly Energy Use Consumption 
by Enduse", "Annual Peak Demand by Enduse", "Monthly Utility Bills - All Rates", 
etc. 
	* These reports reflect the information shown in the BEPU and other common 
eQuest reports from the detailed results. 
	* For example, the BEPU report and the "Monthly Energy Use Consumption by 
Enduse" report have the same #'s for space heating and space cooling 
electricity, as we would expect
	* These standard eQuest output reports reported VERY DIFFERENT numbers for 
space cooling and space heating compared to the numbers derived from the hourly 
reports.
I'm really just putting feelers out there to determine if:
	1. If anyone has encountered such a mis-match before (regardless of system 
type, just a general "hey modelers, has anyone seen this before"_
	2. If anyone has ever followed the hourly report methodology from the 
presentation and done the double-check that we did and had agreement between 
eQuest's reports and their excel calculations
	3. If anyone has run across heat pump heating and cooling energy being reported 
oddly (such as all its energy use being reported as cooling when there is 
obviously roughly a 50%-50% split)
On Sat, Jan 22, 2011 at 1:08 PM, Carol Gardner <cmg750 at gmail.com> wrote:

Hi Gregory,
>
>It's hard to comment without seeing your .inp and .pd2 input files and without 
>knowing exactly what reports you are looking at, e.g. SS-A, SV-A, BEPS, etc. My 
>first thought, however, was to wonder if you are looking at a system report that 
>doesn't include the ventilation load. Some eQUEST reports do and some do not. It 
>would require investigation to determine whether that is the case and since, 
>again, I don't know what exactly you're looking at, I'm not up for it. You might 
>check the documentation about what's in reports, look on the DOE2 website or 
>Google it, to see for yourself.
>
>That's a start anyway.
>
>Carol
>
>
>
>On Fri, Jan 21, 2011 at 3:34 PM, Gregory Raffio 
><graffio at gosustainableenergy.com> wrote:
>
>Paul and the rest of the user group,
>>
>>
>>The attached presentation was a great tool to both confirm and improve our 
>>approach for modeling VRF.  I do have a follow-up question/problem that arose 
>>during the excel work (Slides 33 and 34 of the presentation). 
>>
>>
>>Question: Has anyone ever followed this approach and found out that the results 
>>from the hourly report are significantly different than the "monthly and annual 
>>energy consumption by enduse" reports that eQuest generates?
>>
>>
>>Step-by-step explanation of my process:
>>I created an hourly report exactly as in the presentation with the electric 
>>input to both heat and cool for every system in the facility along with an 
>>hourly report for the building as a whole. When I add up the heating energy and 
>>cooling energy of the individual systems, it equals the heating and cooling 
>>energy for the whole facility, so far so good.
>>
>>
>>Next, we looked at this heating and cooling energy and compared it to the 
>>"monthly and annual energy consumption by enduse" report that eQuest spits out. 
>>These numbers were not in agreement. For example, according to the hourly 
>>reports, the electricity used for space heating is 18,615 kWh while the space 
>>heating electricity in the "monthly energy consumption by enduse" report is 
>>10,930 kWh. Big difference. 
>>
>>
>>In some modeling programs (cough, Trace), I've seen heat pumps output the 
>>combination of their energy in either space heating or space cooling and not 
>>differentiate (which appears to be happening in eQuest as our space cooling 
>>energy is going up in the winter with the VRF system... and the building is 
>>definitely in a heating-dominated climate and has little internal space). The 
>>combination of the hourly report heating and cooling energy was 74,224 kWh and 
>>according to the "monthly energy consumption by enduse" report, the combination 
>>is 64,330 kWh. 
>>
>>
>>I tried adding in the "HP Supp" energy  and some other uses from the "monthly 
>>energy consumption by enduse" report to no avail. I've had another eQuest user 
>>check my excel calculations and my hourly reports and they seem to be in good 
>>working order. 
>>
>>
>>Any guesses, suggestions, strong reactions?
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>On Tue, Oct 5, 2010 at 9:39 AM, Paul Diglio <paul.diglio at sbcglobal.net> wrote:
>>
>>Gary:
>>>
>>>Please find attached file.
>>>
>>>Paul Diglio
>>>
>>>
>>>
>>>
________________________________
 From: "Gary.Schrader at buildings.schneider-electric.com" 
<Gary.Schrader at buildings.schneider-electric.com>
>>>
>>>To: equest-users at lists.onebuilding.org
>>>Sent: Tue, October 5, 2010 9:06:28 AM
>>>
>>>Subject: [Equest-users] VRF/VRV PowerPoint on Modeling
>>>
>>>
>>>
>>>All,
>>> 
>>>At one time I recall seeing a PowerPoint presentation posted to the ListServ 
>>>about how to model VRV/VRF in eQuest. It took you through each of the individual 
>>>steps necessary to create a system.
>>> 
>>>In searching the archives, I believe that this file was scrubbed. Does anybody 
>>>have a copy of it to repost? My understanding is that it was developed by a firm 
>>>out on the west coast, perhaps  Oregon .
>>> 
>>>Thanks,
>>>Gary
>>>
>>>_______________________________________________________________________________________________________________________
>>>
>>>Gary Schrader| Schneider Electric | Buildings Business | Energy Solutions | 
>>>Engineer I
>>>Phone: +1 913 217 8068 | Fax: +1 913 469 0206
>>>Email: gary.schrader at buildings.schneider-electric.com | Site: 
>>>www.schneider-electric.com/buildings | Address:  16011 College Boulevard, Suite 
>>>212 , Lenexa ,  KS 66219 ,  USA
>>>
>>>*** Please consider the environment before printing this email.
>>> 
>>>______________________________________________________________________
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>>
>>
>>-- 
>>Gregory Raffio, LEED AP BD+C
>>Go Sustainable Energy, LLC
>>graffio at gosustainableenergy.com
>>Cell: 773-484-9610
>>Skype: Gregory.Raffio
>>http://www.gosustainableenergy.com/
>>
>>_______________________________________________
>>Equest-users mailing list
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>>To unsubscribe from this mailing list send  a blank message to 
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>>
>>
>
>
>-- 
>Carol Gardner PE
>


-- 
Gregory Raffio, LEED AP BD+C
Go Sustainable Energy, LLC
graffio at gosustainableenergy.com
Cell: 773-484-9610
Skype: Gregory.Raffio
http://www.gosustainableenergy.com/
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