Basement slightly below grade

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Equest users,
I need to model a building that is built partially into a hillside, so that
te basement is partially below grade. One wall of the basement is almost
completely adjacent to earth, and the hill slopes pretty evenly down
towards the opposite side, which is completely exposed. Any tips on how to
reflect this in my model?
Thank for any help here,
-Phil

--

*Phil Boutelle,* *PE, CEM* | Energy Engineer
philboutelle at gmail.com | M (831) 359-5268

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Hi Phil:
If you are not as concerned with the 3-D rendering, I would have half the basement above ground, half below. A simple step. Thermodynamically, it should be fine.
John R. Aulbach, PE
On Saturday, January 21, 2017, 8:29:20 AM PST, Philip Boutelle via Equest-users wrote:Equest users,I need to model a building that is built partially into a hillside, so that te basement is partially below grade. One wall of the basement is almost completely adjacent to earth, and the hill slopes pretty evenly down towards the opposite side, which is completely exposed. Any tips on how to reflect this in my model?Thank for any help here,?-Phil

--

Phil Boutelle,?PE, CEM? ? ?| ??Energy Engineer
philboutelle at gmail.com? ?| ? M?(831) 359-5268

?

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Hi Phil,

As far as modeling a basement half exposed is concerned, you are required
to have the basement above the ground as an above grade floor.
Also then, kindly have the unexposed construction or the face facing the
hill to be underground construction which will have light soil in the layer
as well as very low U value meeting the thermodynamic conditions.
You can use the default underfloor constructions.
The layer will help you to have the properties like wall facing soil and
low U value to meet the low heat transfer as far as hill is concerned.
I think the default underfloor construction is such as that it would meet
the requirements with low U value of 0.010 Btuh / sq. feet/ degree F.
As far as the hill part is concerned the result shall show it.

*Thanks,*
*Sharad.Kumar*
*..........................................................................................................................................................................*

On Saturday, January 21, 2017, 8:29:20 AM PST, Philip Boutelle viaEquest users,

I need to model a building that is built partially into a hillside, so that
the basement is partially below grade. One wall of the basement is almost
completely adjacent to earth, and the hill slopes pretty evenly down
towards the opposite side, which is completely exposed. Any tips on how to
reflect this in my model?
Thank for any help here,
-Phil

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400

Phil,

To add a little more detail to splitting the wall in two?

1. Make a copy of the basement wall.

2. Raise the bottom of one of those walls and make sure it has an above-grade construction.

3. Lower the top of the other wall and make sure it has a below-grade construction.

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

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Joined: 2016-07-15
Reputation: 400

Earlier answers answer to the most time-efficient approximations/methods.

But? Semi-exposed basements are the perfect opportunity to learn how to do some detailed geometry manipulations through the eQUEST interface!

This involves a few more steps for no appreciable gains in simulation accuracy, but from a learning/training perspective this will get you more comfy with detailed edits (which will get you out of some tight spots in more complex scenarios, and also put you in a good spot to tackle more complex challenges). That it will ?look? right is just icing on the cake ;):

0. Starting point (this is easier to demonstrate when you don?t have plenums specified for below-grade spaces). I?m going to make the highlighted surface our ?fully exposed? basement wall:
[cid:image001.png at 01D27722.866B0640]

1. Select the fully exposed wall, and delete it via right clicking in the component tree:
[cid:image002.png at 01D27722.866B0640]

2. Right-click the associated parent space in the component tree > Create Child Component . Create child Exterior Wall?
[cid:image003.png at 01D27722.866B0640]

3. (continuing) ? Choose to copy another exterior wall, and give it a recognizable name if you like
[cid:image007.png at 01D27723.25CF29A0]

4. Based on whatever you copied, you might need to toggle the vertex (i.e. ?V1 vs. V2 vs. etc? of space polygon?) and/or re-initialize / refresh the 3D view, but on choosing the correct vertex you should see the surface appear in the 3D view:

[cid:image006.png at 01D27723.997CCF60]

5. Now select one of the ?sloping exposures,? and double click it in the component tree to review its inputs:

[cid:image008.png at 01D27723.997CCF60]
[cid:image009.png at 01D27723.997CCF60]

6. Note the height/width dimensions (12.00 and 91.30 in this case). We?re going to make a polygon with that info.

7. Scroll down to polygons in the component tree, right-click, create polygon.

8. Give it a name & create from scratch:

[cid:image010.png at 01D27724.41366EA0]

9. Polygons require a minimum of three vertices to start? handy that our example is a triangle, eh?

[cid:image011.png at 01D27724.CDAC8810]

10. A few tips here:

a. This is EXACTLY like what you?re used to seeing in the wizards for tracing out CAD zones.

b. Specifying vertices in a counter-clockwise fashion is still a good idea

c. Imagine an X-Y plane with the origin at one of the associated SPACE floor vertices ? from there you can figure out which direction to go first.

11. Return to the underground surface at-hand, and assign the polygon you just made:

[cid:image013.png at 01D27725.22681EF0]

12. Now, just like the fully exposed wall, create a new exterior surface under this space. Copy the custom exterior wall you made for that case.

[cid:image014.png at 01D27725.22681EF0]

13. If you highlight it in the 3D view, you can see it also needs to be turned into a triangle. It?s exactly the same process. We could save a minute and round an aesthetic corner by assigning the same custom polygon you made for the underground exposure, but that?s not what tutorials are for! Note for this second polygon, I?m plotting points relative to the same space vertex as the origin (this keeps everything on the same plane):

[cid:image015.png at 01D27727.5A5E11F0]

14. Assign the new polygon to our new exterior surface and voila! Rinse and repeat for the opposite side and you?ll have exactly the scenario you posed represented in your model..

[cid:image012.png at 01D2772A.05D71840]

15. In the interest of at least addressing absolute accuracy, so that we know where it lies, a few extra steps would accurately represent the perimeter floor losses:

a. The basement level space hosting the fully exposed wall after this exercise will have more in the way of actual floor perimeter losses than would be spit out from the wizards. Remember, the wizards thought this would be a basement floor 12 ft under grade. If I wanted to lock that down, I?d create a geometrically identical on-grade space in the wizards, using appropriate inputs for the associated constructions and perimeter insulation (as occurring), finish the wizards to generate the INP, then copy the inputs for the resulting underground construction tied to that space?s on-grade floor over to the basement-level floor for my ?working? model.

b. Similarly, the perimeter floor losses for the two ?semi-exposed? sides will be slightly higher than the wizards? generated floor constructions will represent. The amount of heat loss on the ?fully underground? side is going to be minimal, and losses per lineal foot will approach fully exposed levels as you approach the ?fully exposed? corner. Intuitively I don?t think this would be a linear function (someone more practiced in underground 3D heat transfer studies would know ? shoutout to Neal Kruis?), but that?s probably a close enough approximation.

c. Losses on the face remaining fully under grade should be correct as generated by the wizards ? no work there.

You could go on to specify doors / windows on the exterior surfaces if desired.

Hope that helps a few of you!

~Nick

[cid:image004.png at 01D27722.866B0640]
Nick Caton, P.E., BEMP
Senior Energy Engineer
Regional Energy Engineering Manager
Energy and Sustainability Services
Schneider Electric

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

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

[cid:image005.png at 01D27722.866B0640]

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