light tubes and light wells

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I'm trying to model a light tube and a light well in eQuest. I'd like to
bring light into the core and maybe a lower level and have this reduce the
lighting required.

so, I create a window in the roof, change the window to "Tubular
Daylighting device" and have a daylighting sensor in the space below (a
core zone).
But there is no effect on the lighting energy. This is the same if I use a
skylight (aka a light well).

Has anyone used this successully?


norman wheatley's picture
Joined: 2011-10-02
Reputation: 0

Is your simulation going through successfully? Typically, just creating
a skylight in an existing roof (which I am guessing is currently
attached to your core plenum space) gives you an error.
You will have to create a new roof for the core space, use 'Skylt Roof
Construction' as the construction, and then create the skylight in this
new roof. See if this works.

Umesh Atre's picture
Joined: 2011-09-30
Reputation: 0


An extra thought: Don't count on daylight moving between/across
spaces... If your window is in roof surface that's a child of a plenum
space, I believe the light will only be measurable in the plenum for
daylighting control purposes.

An approach for detailed mode that may be instructive for core spaces
remote from the exterior: If your core space does not already have an
exterior surface defined, you will want to create one to host the
window. It could be a wall/roof... don't think it really matters. Play
with this exterior surface's location/dimensions/orientation until it is
situated above and parallel to your roof surface above, then create a
window within this remote exterior surface. Light should then "jump" to
the core space, bypassing any plenums or other spaces along the way.

Best of luck!



Nick-Caton's picture
Joined: 2011-09-30
Reputation: 805

I was thinking exactly along the lines of Nick - if you have a plenum you need to create a dummy roof to house you light tube. Just another thing to add - the wall that you host this light tube on is going to behave like it was a roof to the space (in terms of conductance) so you probably want to create a material that makes it close to adiabatic (high R-value material)

Vikram Sami, LEED AP BD+C

Sami, Vikram's picture
Joined: 2011-09-30
Reputation: -1

Vikram & Nick, you are both correct.
I suggested creating the new roof surface with the 'Skylt Roof
Construction' (this is a construction in the library with U-value
0.001), and
attaching it to the core space vs the plenum for the same reasons that
you mention.

Umesh Atre's picture
Joined: 2011-09-30
Reputation: 0