Modelling heating

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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

Rathna Shree's picture
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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"

Joe Huang's picture
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1) Make sure your zoning pattern will not require any reheat. Certain VAV
zones served by the same system may require reheat if the central ahu
supplies much cooler air than what is required by some zones.
2) If there is no heating system in your building you should not include it
in the model. Make sure the heating system is set to Not installed. Then
the heating setpoint does not even matter.

k bk's picture
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Joined: 2015-03-26
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But ASHRAE 90.1 appendix G requires identical heating to be modelled in both base and proposed case. So modelling a setpoint such that heating doesn't switches on is important.But how much ever lesser temperature i model, heating energy consumption is coming down but fan energy consumption is going up due to Zone fans (PFP boxes).

1) Make sure your zoning pattern?will not require any reheat. Certain VAV zones served by the same system may require reheat if the central ahu supplies much cooler air than what is required by?some zones.2) If there is no heating system in your building?you should not include it in the model. Make sure the heating system is set to Not installed. Then the heating setpoint does not even matter.
?
?

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

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"
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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Rathna Shree's picture
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Hi,
According to Ashrae 90.1-2007 Appendix G Table 3.1.10 d "Where no heating system exists or no heating system has been specified, the
heating system classification shall be assumed to be electric, and the system characteristics shall be identical to the system modeled in the baseline building design."So you can not set the heating as not installed.

------------------
Yongqing Zhao
Changsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan
Telephone:13574805636
Email:zhaoyongqing1987 at 126.com
503271081 at qq.com

------------------ ???? ------------------
???: "Rathna Shree";;
????: 2015?3?26?(???) ??3:16
???: "Joe Huang"; "bldg-sim at lists.onebuilding.org";

??: Re: [Bldg-sim] Modelling heating

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

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
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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=?GB2312?B?1dTTwMfg?='s picture
Joined: 2013-07-05
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Exactly. Thats the reason, i want to model such a way that heating never switches on and even the zone fans (PFP boxes) never comes on. I am not able to exactly figure out how to do that?

Hi,According to Ashrae 90.1-2007 Appendix G Table 3.1.10 d "Where no heating system exists or no heating system has been specified, the
heating system classification shall be assumed to be electric, and the system characteristics shall be identical to the system modeled in the baseline building design."So you can not set the heating as not installed.?------------------Yongqing ZhaoChangsha Green Building & Energy Saving Technology CO.,LTD
NO.438,Shaoshan Road,Changsha,Hunan?
Telephone:13574805636Email:zhaoyongqing1987 at 126.com???????? 503271081 at qq.com??

------------------??????------------------???:?"Rathna Shree";;????:?2015?3?26?(???) ??3:16???:?"Joe Huang"; "bldg-sim at lists.onebuilding.org"; ??:?Re: [Bldg-sim] Modelling heating
Thank you Joe Huang. I am using Equest for the simulation. Can we set the heating as not installed for LEED submissions?

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"

Rathna Shree's picture
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Joined: 2011-10-02
Reputation: 0

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"

Joe Huang's picture
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Joined: 2011-09-30
Reputation: 406

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"

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