Dear forum,
I have not followed this thread closely, but I doubt that it’s a simple matter to model a specific boiler’s part-load efficiency without a lot of data. I think some of the condensing boiler catalogs have enough data to make a decent curve, but I don’t know if it’s common.
For a Baseline boiler, I agree with Francesco – it’s not worth spending a lot of time refining the efficiency of a “fictitious” piece of equipment. My approach so far is to use the ASHRAE 90.1 required efficiency and also to use a curve that reflects some degradation at low loads. After I read the AHRI test procedure (and after I wake up the next morning J) I’ll see if that makes sense.
Thanks for the link Francesco!
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of FrancescoP
Sent: Friday, August 10, 2012 10:02 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Re: Boiler efficiency according to ASHRAE (e.g. according to CFR)
Thank you Javed,
it seems that the test conditions are indicated here:
http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/BTS-2000.pdf
During the test the "outlet water temperature" has to be maintained at "180°F" (i.e. 82°C). Unsurprising, 82°C is also the hot-water supply temperature for the baseline model according to G3.1.3.3 (ASHRAE 90.1-2007).
Modeling the thermal efficiency of the baseline model has constant would be a good idea? It doesn't correspond to a real boiler, but to a reference boiler.
Regards
Francesco
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Javed Iqbal <eee.javed@...> wrote:
>
> Hi,
>
> You can find 10 CFR Part 431 boiler test procedure here. look at page no.
> 461 .
> http://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol3/pdf/CFR-2011-title10-vol3-part431.pdf
>
>
> Check this for Boiler efficiency. ..
> http://www.designbuilder.co.uk/helpv3/Content/Boilers.htm
>
>
> On Fri, Aug 10, 2012 at 5:00 PM, FrancescoP <direzionecontraria@...>wrote:
>
> > **
> >
> >
> > I'm developing a baseline model for LEED certification. The boiler
> > efficiency has to respect Table 6.8.1F of ASHRAE 90.1:2007. The thermal
> > efficiency Et shall be equal to 80% according to the test procedure 10 CGR
> > Part 431. I'm modeling the boiler using the object Boiler:HotWater. I
> > imposed the "nominal thermal efficiency" equal to 0,8 but what about the
> > "normalized boiler efficiency curve"? Any suggestion, please?
> > Do you have any information regarding the conditions of the test procedure
> > 10 CFR Part 431?
> > With Regards
> > Francesco Passerini
> >
> >
> >
>
>
>
> --
>
>
> Javed Iqbal, LEED AP, CEA
> Energy Analyst
>
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___