[Bldg-sim] Modelling heating

[Nicholas Caton]

Hi Rathna,



It may be worth your time to peruse the CIR archives, or even to further
submit a formal query to GBCI with reference to your specific LEED project
prior to preliminary submission, to find for those specific
climates/regions of the world whether there may be some precedent
supporting your proposition to exclude heating altogether.  The
conservative/safe approach remains to stay the course of modeling heating
in both cases, as prescribed.



Before launching such a query – I would advise you to revisit your
assertions:  It’s seems rather shaky to simultaneously claim heating isn’t
broadly necessary based on your climate, and to observe space heating and
associated fan energies are a relatively big deal with regard to your
simulation results.



As far as I understand the intent of 90.1, in line with Joe’s suggestion,
the general requirement to simulate space heating for *conditioned**
spaces, even where none is installed, is rooted in the idea that a new or
renovated building should typically be trying to maintain occupant comfort
through all seasons.  If we hang the intent on “comfort” as the operating
word, it doesn’t take much of a stretch of the imagination to consider
there are occupant demographics, processes, activities, and indeed regions
of the world where the definition of a “normal” range of temperatures to
achieve comfort diverges from a ‘typical’ 70-75F during occupied hours.
It’s my general impression, and my practice, to assert the modeler has the
flexibility to assign thermostat setpoints as appropriate to reflect the
actual design, and within reason (i.e. to maintain comfort), so long as
those thermostat setpoints/schedules are held equal between both baseline
and proposed models.



On a related tangent, it’s probably worth a mention:  for LEED 2009
presently, GBCI seems to have pretty much fully adopted the notion to
permit/encourage the use of 90.1-2007 addendum ‘dn’ (Adding the
“heating-only” baseline systems #9 and #10 as they appear in 90.1-2010),
for the opposite scenario where you have heating only and no cooling in the
proposed design.



With specific regard to application in eQuest, the simplest way to remove
the call for heating *altogether* in many models is to remove the inputs
for zonal heating thermostat schedule assignments (HEAT-TEMP-SCH).  An
intermediate solution would be to modify those thermostat heating schedules
to pull the setpoints downwards, thereby reducing hours where heating is
called for.



Leverage this knowledge prudently – it’s well within reason to expect your
reviewers to require a full accounting/explanation of your simulation’s
thermostat schedules if the project’s heating energies diverge wildly from
similar projects in that region, especially if heating is missing entirely!



* Take note that  “*conditioned*” is a 90.1 glossary term – it’s worth
reviewing where this does and does not apply within your project, if you
are unfamiliar.



~Nick



*NICK CATON, P.E.*
*Owner*



*Caton Energy Consulting*
  1150 N. 192nd St., #4-202

  Shoreline, WA 98133
  office:  785.410.3317

www.catonenergy.com



*From:* Bldg-sim [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf
Of *Joe Huang
*Sent:* Thursday, March 26, 2015 10:23 AM
*To:* Rathna Shree; bldg-sim at lists.onebuilding.org
*Subject:* Re: [Bldg-sim] Modelling heating



The intention to always require heating in the base case is to prevent
people from claiming energy savings simply by not providing any space
conditioning!  However, if your building and climate makes heating
unnecessary, that should show up in your base case simulations where the
heating system never comes on. You should still use a reasonable heating
schedule, e.g., 21 C (70F) during the day and 18.3C (65F) at night (or
maybe even 15.6C (60F) if building is unoccupied), just to prove that
heating is indeed unnecessary.  You might also track the indoor
temperatures of your proposed building to convince LEED reviewers that
indoor temperatures are always above the comfort zone.

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 3/26/2015 12:16 AM, Rathna Shree wrote:

Thank you Joe Huang. I am using Equest for the simulation. Can we set the
heating as not installed for LEED submissions?





On Wednesday, 25 March 2015 11:59 PM, Joe Huang
<yjhuang at whiteboxtechnologies.com> <yjhuang at whiteboxtechnologies.com> wrote:



It all depends on which simulation program you're using, but all of them
should be able to accommodate you very easily.  You can either set the
Heating Schedule to be never on, and the Heating Setpoint Temperature to
something very low, like 10 C (50 F).

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 3/25/2015 2:58 AM, Rathna Shree wrote:

Dear All,



In few of the climatic conditions we work on doesn't require heating at
all. The temperature might go little less than 20deg C in winter but
heating will definitely not be installed in the project. For these
projects, how do we set the heating set point temperatures so that heating
never switches on. we are facing issues especially while modelling VAV with
PFP boxes in equest (PIU systems). The base case and proposed case heating
and fan energy consumption are highly affecting the final savings results.
I am looking to avoid this scenario and ensure heating never switches on,
therefore zone fans also do not work.



Please guide.



Regards,

Rathnashree



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