[Equest-users] [Bldg-sim] Expert advice on Wall Insulation study in eQuest

Tue Apr 28 11:56:22 PDT 2015

Dan,

Very good point!   I didn't even think about this, i.e., that the plot was against 
conductance and not resistance.
Therefore, I would conclude that eQUEST is behaving properly.

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 4/27/2015 11:12 AM, Daniel Knapp wrote:
> Hi Mayank,
>
> I think on further reflection you are seeing exactly what you should be seeing. The 
> energy consumption should go down linearly with the U-value. What does saturate is the 
> energy savings compared to insulation thickness or R-value which is plotted as 1/U. Here 
> is a graph of energy vs. U and energy vs R for your building:
>
> All the best,
> Dan
>
>
>
> —
> Daniel Knapp, PhD, PPhys, LEED® AP O+M
> danielk at arborus.ca <mailto: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 Apr 27, 2015, at 6:15 AM, Mayank Bhatnagar <mayank.23aug at gmail.com 
>> <mailto:mayank.23aug at gmail.com>> wrote:
>>
>> Thank you Joe and Daniel for your response.
>>
>> As you suggested, I checked LS-C report for wall conduction variation w.r.t. U-value. 
>> It is also giving linear trend for wall conduction. Additionally, I have done same 
>> analysis for without internal loads (occupancy, lighting and equipment load) as Joe 
>> indicated about the compounding effect. I still get linear trend between the energy 
>> consumption and U-value.
>>
>> For your reference, I am attaching inp, pd2 and weather file.
>>
>>
>>
>> On Thu, Apr 23, 2015 at 8:10 PM, Joe Huang <yjhuang at whiteboxtechnologies.com 
>> <mailto:yjhuang at whiteboxtechnologies.com>> wrote:
>> Mayank, Daniel,
>>
>> I think it's a good idea to look at the component loads in the LS-C reports, but I want 
>> to add some words of caution.
>> The loads (actually heat flows) shown in those reports are calculated at the constant 
>> Reference Temperature, and categorized as either heating or cooling if the total load 
>> of the building that hour is negative or positive. These loads are corrected when DOE-2 
>> solves for the actual room temperature based on simple UA-deltaT principles.  If you 
>> want the corrected wall loads, you need to get an hourly report of the wall loads 
>> and then correct for the temperature difference Troom - Treference.
>>
>> I'm not sure if this level of detail is warranted, though.  I also suspect there's some 
>> other compounding effect that's giving you the results that you report.
>>
>> 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
>> http://www.whiteboxtechnologies.com
>> (o) (925)388-0265
>> (c) (510)928-2683
>> "building energy simulations at your fingertips"
>>
>>
>> On 4/23/2015 6:18 AM, Daniel Knapp wrote:
>> Hi Mayank,
>>
>> I recommend opening up the SIM file (you can do this by going to Tools -> View 
>> Simulation Output) and looking at the LS-C and LV-D reports. In the LS-C report you can 
>> find the contribution to the peak heating and cooling loads that come from the walls. 
>> From this you should be able to figure out how the wall conduction is changing as a 
>> fraction of the peak loads as you decrease the wall U-value. In the LV-D report (scroll 
>> to the very end of it) there is a summary of the U-values for each exterior surface. 
>> This might be a good place to look to make sure that the effective U-values that eQUEST 
>> is simulating are matching up with your expectations of what the U-values should be.
>>
>> I would agree that the energy savings should saturate at some point.
>>
>> All the best,
>> Dan
>>
>>
>> —
>> Daniel Knapp, PhD, PPhys, 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 Apr 23, 2015, at 5:00 AM, Mayank Bhatnagar <mayank.23aug at gmail.com> wrote:
>>
>> Hi Claire,
>>
>> Thanks for your response.
>>
>> The analysis has been done on an 8 hour operating office building in New Delhi. The 
>> mechanical system is packaged single zone system with electric resistance heating.
>>
>> Please let me know if you need more information.
>>
>> Thanks
>>
>> Regards,
>> Mayank
>>
>> On Thu, Apr 23, 2015 at 2:25 PM, Claire Das Bhaumik <claire at inklingllp.com> wrote:
>> Mayank,
>>
>> I think we need to know a bit more about the building:
>> - Location (some parts of India are cool, others hot!)
>> - Building usage - office, domestic, retail? Hours of use?
>> - Servicing - heating and cooling? Mechanical or natural vent?
>>
>> Regards,
>>
>> Dr Claire Das Bhaumik CEng FCIBSE
>>
>> Partner - Inkling LLP
>>
>>
>> e: claire at inklingllp.com
>>
>> t:  07950 282800
>>
>> w: www.inklingllp.com
>>
>> Follow us on Twitter: @DasInkling
>>
>> Partnership No. OC367619
>>
>>
>> On Thu, Apr 23, 2015 at 9:51 AM, Mayank Bhatnagar <mayank.23aug at gmail.com> wrote:
>> Dear All,
>>
>> We are working on a national level research project in India. A building envelope 
>> analysis is a part of this project. By doing analysis, we have found a vague results in 
>> trend (linearly downward) of reduction in energy consumption with reducing wall U-value 
>> in eQUEST.
>>
>> Theoretically, the energy consumption should approach to stagnant with reduction in 
>> wall U-value.
>>
>> Please refer figure.
>>
>> Appreciate if anyone put light on this.
>>
>> Thank you.
>>
>> Regards,
>>
>> Mayank Bhatnagar
>>
>> Theoretical should come like this.
>> <image.png>
>>
>> In eQuest the trend is-
>> <image.png>
>>
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>> <Small Office Bldg_v5_4.pd2><Small Office Bldg_v5_4.inp><IND_New.Delhi.421820_ISHRAE.BIN>
>

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