Outside wall to outside wall

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Tough call, but I?d probably be conservative and err on the side of making assumptions that result in MORE energy consumption in my modeling (unless there is some benchmarking you can compare to).

That means I?d probably assume the walls are exterior and fully shaded. There is a pretty good chance there is at least small dead-air-space between the buildings (even if it is only a few inches), plus you have no control over what is happening on the other side of the wall? maybe the neighboring building is minimally conditioned, or becomes abandoned.

Nathan Miller, PE, LEED AP BD+C ? Mechanical Engineer/Senior Energy Analyst
RUSHING | D 206-788-4577 | O 206-285-7100 | C 207-650-3942
www.rushingco.com

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Thank you all. I just had to shake the trees to jog my DOE-2.1 memory.
A fully shaded outdoor wall is probably the best way, so thank you all.
John

#yiv7061350929 #yiv7061350929 -- _filtered #yiv7061350929 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv7061350929 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} _filtered #yiv7061350929 {font-family:Verdana;panose-1:2 11 6 4 3 5 4 4 2 4;}#yiv7061350929 #yiv7061350929 p.yiv7061350929MsoNormal, #yiv7061350929 li.yiv7061350929MsoNormal, #yiv7061350929 div.yiv7061350929MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}#yiv7061350929 a:link, #yiv7061350929 span.yiv7061350929MsoHyperlink {color:#0563C1;text-decoration:underline;}#yiv7061350929 a:visited, #yiv7061350929 span.yiv7061350929MsoHyperlinkFollowed {color:#954F72;text-decoration:underline;}#yiv7061350929 span.yiv7061350929EmailStyle17 {color:#1F497D;}#yiv7061350929 .yiv7061350929MsoChpDefault {font-size:10.0pt;} _filtered #yiv7061350929 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv7061350929 div.yiv7061350929WordSection1 {}#yiv7061350929 Tough call, but I?d probably be conservative and err on the side of making assumptions that result in MORE energy consumption in my modeling (unless there is some benchmarking you can compare to). ? That means I?d probably assume the walls are exterior and fully shaded. There is a pretty good chance there is at least small dead-air-space between the buildings (even if it is only a few inches), plus you have no control over what is happening on the other side of the wall? maybe the neighboring building is minimally conditioned, or becomes abandoned. ? ? Nathan Miller, PE, LEED AP BD+C ?Mechanical Engineer/Senior Energy Analyst RUSHING|D206-788-4577 |O206-285-7100 |C207-650-3942 www.rushingco.com ?

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John,

If the wall touches the other building and the other building is about the same temperature (not an open parking garage) so that there is no heat transfer through the wall, then I would treat it as an adiabatic wall.

If there is a gap, I would treat it as an outside wall and put a site shade right next to it.

If the gap is really small so that it?s neither totally exposed to the outside ambient conditions nor totally adiabatic, you could increase the wall?s effective R-value to approximate the heat transfer rate you think is really happening.

Keith Swartz, PE | Senior Energy Engineer
Seventhwave
608.210.7123 seventhwave.org

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John, looks like this didn?t leave my outbox? sorry! Give me time to refine my response:

How I?d react would depend on my motives/goals.

Ideally, I?d like to find & assert both neighbors are conditioned to similar temperatures and therefore declare no substantive heat transfer: adiabatic surfaces with thermal mass to effect hourly heat storage/transfer lag. This is probably accurate enough (in-aggregate) for many cases, short of exposed walls where one building is taller than another.

Conservatively ? Nathan?s suggestion is the ticket however. If there?s going to be appreciable heat transfer, you?re now in a position to decide where to draw a line in the sand: what?s your worst-case? This may be the more appropriate response if you?re doing simulation to aid/inform equipment sizing or if you know of planned demolition/renovations in the neighboring spaces. I can say short of FEMA shelters and the like (this is tornado country?), I don?t normally make the destruction of an attached portion of my buildings a part of my design calculations or energy simulations, but you might have some good reasons to pull that possibility into the picture.

Applying the likes of 90.1 conditioned envelope definitions notably gets a little trickier if you have an enclosed or partially enclosed gap between the buildings. If you?re heading down a 90.1/LEED based simulation path or something similar for compliance, look hard for shared wall/space construction details on that front to understand what exactly lies beyond your ?envelope.?

Finally, I notice you mentioned an disquieting location: New York City (or NEW YORK CITY?!? as we say in the midwest). I want to say there was a mailing list discussion on this exact issue in relation to NY?s energy standards some time back either in equest-users or bldg-sim? but on cursory searching I?m having trouble finding it? suggest digging the archives further!

~Nick

Nick Caton, P.E.

Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric

D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

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Thanks, Nick. I have an even more interesting scenario. This building was built originally in 1855 (yes, even before me and 19 years after the Battle of the Alamo)). The owners will leave the concrete 1855 side walls (I think I will let them be totally shaded outside walls), gut the rest of the building, and rebuild a 5 story single residence (no, not one of the Trump kids).
SO..for the City of New York 2011 Energy Code (2014 doesn't take place until October, 2016), we use ASHRAE 90.1-2010. Good old Appendix G (as I interpret it) say that, for either New or Alterations, the Base model is Steel Frame. ALL of it. So I don't apply the 1855 walls (with some added insulation) until the Proposed Run (Thank GOD I don't have to spin the building like LEED).
Does this base building approach seem correct to you?
Don't forget. I am originally a Chicago boy.
John

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| ? Senior Energy Engineer
? Energy and Sustainability Services
? Schneider Electric | D??913.564.6361
M??785.410.3317
E??nicholas.caton at schneider-electric.com
F??913.564.6380 | 15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States |
| |

? ?

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John,

It would be worth checking in the tables in Appendix G ? however, there used to be the following wording at the bottom of the baseline performance column?

Existing Buildings. For existing building envelopes, the baseline building
design shall reflect existing conditions prior to any revisions that are part of
the scope of work being evaluated.

This one is from ASHRAE 90.1 (2007) and I?m not sure if it is in the 2010 version but it would be worth a look.

Though modeling 1855 concrete side walls would be a different issue, entirely! LOL.

Good luck, sir!

Chris Baker
CCI Alliance of Companies
Fort Wainwright, AK

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Confirming ? that language remains in 90.1-2010. I?ve had similar experiences with old concrete & masonry buildings (zero insulation), where that?s turned out to be a boon for the likes of LEED points.

Also since it sounds like you?re dancing with compliance, be advised for any prescriptive purposes those concrete walls are most likely a mass wall by 90.1 definitions.

Sounds like a fun one alright!

Nick Caton, P.E.

Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric

D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

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Hi Folks,

Just a heads up that this language is removed from 90.1 ? 2013. We?ll still be able to get the point bumps on LEED v4 projects since the baseline is 90.1 ? 2010, but it will impact new code adoption in certain states. There are also key changes to the window to wall ratio baseline requirements and baseline building rotation. We?ve been prepping for the imminent code changes in MA and have had to deal with these things?.

Good luck with that project John!

-Dana

----
Dana Etherington | PE, CEM, BEMP, WELL AP
RDK Engineers
P: (857) 221-5920 | C: (617) 583-3009 | F: (617) 345-4226

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Too many tag emails !!
Nick, remember, this is only the two side walls to remain. Everything else is to be gutted and replaced. So the Base is two side mass walls, and front/back are steel frame ?? Never build a building this way !!
John

Hi Folks, ? Just a heads up that this language is removed from 90.1 ? 2013. We?ll still be able to get the point bumps on LEED v4 projects since the baseline is 90.1 ? 2010, but it will impact new code adoption in certain states. There are also key changes to the window to wall ratio baseline requirements and baseline building rotation. We?ve been prepping for the imminent code changes in MA and have had to deal with these things?. ? Good luck with that project John! ? -Dana ? ---- Dana Etherington | PE, CEM, BEMP, WELL AP RDK Engineers P: (857) 221-5920 | C: (617) 583-3009 | F: (617) 345-4226 ?

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John,

Is this building a brownstone or something? Is it a brick building? Is the brick structural or just a veneer? (Hint: Look for weepholes if you can't look inside a wall, as I doubt you have any original plans). Where's this building located out of curiosity (neighborhood)? I'm not that familiar with 5-story brownstones (brooklyn brownstones are as far as I remember it most commonly 3-4 stories at least).

Is this a purely energy code compliance model (for trade offs) or are you modeling for EPact tax deductions?

If you're using the model to size your equipment is definitely wouldn't consider these side walls as adiabatic. I've seen first hand someone who started having temperature problems as the building next door went unoccupied for an extended period of time before it was knocked down. There are plenty of way to ensure that this extra capacity won't end up hurting your part load performance.

Julien

Envoy? de mon iPhone

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I think you?re in a position to make an interpretation.

The simpler interpretation (maybe) is that the entirety of the new envelope is a revision to the existing envelope, and therefore all of the baseline walls (and roof) = whatever was there to start, before demolition/gutting begins.

This interpretation could be relatively helpful, harmful, or neutral concerning to your performance rating. In my experience with large and relatively uncomfortable/ancient military facilities in the Midwest with zero insulation and bad infiltration, this interpretation turned out to be quite helpful.

If you want to draw a line and say the side walls are existing/renovated but the front/back walls are entirely new construction (I?ve never done this, but this passes logic as well), then I?d expect the sidewalls to reflect original conditions and the front/back to reflect steel frame baseline wall construction.

I only mentioned reviewing the mass walls definition in the event you have to discuss prescriptive compliance options (i.e. what?s in the envelope tables) ? I don?t think that nuance will matter for any Appendix G based exercise... sorry for any undue confusion!

Wouldn?t be a bad idea to seek some written agreement of your interpretation with whoever is going to be reviewing your outputs.

~Nick

Nick Caton, P.E.

Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric

D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

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Hi John,

For tilted wall one can have a help from the following box.It can be just
by right clicking on the supposed wall.

[image: Inline image 1]

Just change the tilt angle.

Then if the wall is aligned to the other building then the problem can be
resolved.Then it can be outside to outside wall.

Thanks,
Sharad.

*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
Behalf Of *John Aulbach via Equest-users
*Sent:* Wednesday, August 31, 2016 5:42 PM
*To:* via Equest-users
*Subject:* [Equest-users] Outside wall to outside wall

Hi Gang:

Food (and query) for thought.

I am doing a remodel of a New York Building that is essentially a tenement
(?). Building squished between other buildings. Side walls essentially lay
against next building.

Inside wall? Outside wall with no solar?

How would you model this?

John R. Aulbach, PE

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