Hi,
I am attempting to model energy saved by installing electrochromic glass
for use in a large west facing lobby area into eQUEST. Given that eQUESTS
capabilities only include modeling a single tint for a pane of glass in a
shell, how would I go about analyzing electricity consumption with the
electrochromic glass for each hour over the course of a year? If anybody
either has thoughts on this or has done this in the past, I would sure
appreciate it.
Thanks,
-Brian Cline-
Hi Brian,
Actually I think you are in luck!
Electrochromic glazing is directly addressable. For one possibility, you
can have the transmittance adjust each hour based upon the incident solar
radiation (or other variables) for each window:
In detailed edits (past the wizards), check out the second tab after double
clicking on any window in the component tree. Review the associated DOE-2
help entries under Volume 2: Dictionary > Envelope Components > WINDOW >
Switchable Glazing.
You?ll need to become familiar with the actual system?s ?hi? and ?low?
state properties, and also with how the system is controlled. There are a
variety of options to emulate different control schemes.
The only frustration I?ve experienced using eQuest for ?smart glass? was
with a request to address manual overrides. For systems featuring a ?force
shade/clear? function, I haven?t found great guidance to reinforce when/how
occupants might use that feature, so it becomes a tricky matter to carry
into the simulation without a series of my own assumptions. If anyone has
come across some research or polling along these lines I?d like to add that
to my library!
~Nick
*NICK CATON, P.E.*
*Owner*
*Caton Energy Consulting*
603 N Ferrel
Olathe, KS 66061
office: 785.410.3317
www.catonenergy.com
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
Behalf Of *Brian Cline
*Sent:* Tuesday, July 21, 2015 5:32 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] Problem with Sage Glass Analysis
Hi,
I am attempting to model energy saved by installing electrochromic glass
for use in a large west facing lobby area into eQUEST. Given that eQUESTS
capabilities only include modeling a single tint for a pane of glass in a
shell, how would I go about analyzing electricity consumption with the
electrochromic glass for each hour over the course of a year? If anybody
either has thoughts on this or has done this in the past, I would sure
appreciate it.
Thanks,
-Brian Cline-
I received the attached files from Sage Glass for my eQUEST model. Contact Josh ? see below- for additional information.
Josh Battles, LEED Green Associate | Architectural Solutions Manager | o:507-331-4921 c:507-323-5626 | josh.battles at sageglass.com
www.sageglass.com
Sincerely,
[ARCH | NEXUS][Facebook][Youtube][LinkedIn]
DAVID W. GRIFFIN II
BEMP
ENERGY ANALYST
2505 E Parleys Way
Salt Lake City, UT 84109
Office 801.924.5028
archnexus.com
[Twitter]
As others have indicated, yes, this can be modeled in eQUEST.
Rather than using the library file provided by a vendor, we created our
own G-T-C descriptions using the WINDOW 6 program and importing into
eQUEST. We found some interesting bugs/constraints that I think might
help reduce some headache for others, and in the case of #1, give more
realistic results. Haven't reviewed the materials provided by Josh to
see if these are now addressed in the directions provided by Sage Glass,
though I did forward this to them earlier this year when we discovered them.
1. In eQ v3.63 and 3.64, the import of WINDOW data neglected to
populate the FILMS-COND keyword when creating the custom
GLASS-TYPE-CODE (G-T-C). This resulted in much lower U_cog values
than expected. We tested import with v3.65 and this bug appears to
have been fixed.
2. If used for switchable glazing, the GLASS-TYPEs referenced by WINDOW
objects must be listed in the input file in consecutive order.
Otherwise, a BDL error will result.
3. If used for switchable glazing, the G-T-Cs used must have an numeric
integer name that is >1000. Otherwise, a BDL error will result.
Hope this helps,
David
Does anyone know which values I should use for 'switch high' and 'switch
lo' for the window properties in the detailed design wizard? At the moment,
I am using 2862 and 2863 glass types to model tinted and un-tinted glass. I
am also using the 'direct sol inc' option for the switch control.
IIRC, the switch-hi properties correspond to when the variable (direct
solar radiation in your case) is at the high point you provide.
If #2862 is the relatively tinted option, I would intuitively assign that
as the ?switch hi? option.
To move your simulation towards better accuracy, you will probably want to
define custom glass types for both the ?switched? and ?unswitched? states,
with reference to the properties specified/documented for the product you
are emulating.
~Nick
*NICK CATON, P.E.*
*Owner*
*Caton Energy Consulting*
306 N Ferrel
Olathe, KS 66061
office: 785.410.3317
www.catonenergy.com
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] *On
Behalf Of *Brian Cline
*Sent:* Monday, July 27, 2015 12:27 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Problem with Sage Glass Analysis
Does anyone know which values I should use for 'switch high' and 'switch
lo' for the window properties in the detailed design wizard? At the moment,
I am using 2862 and 2863 glass types to model tinted and un-tinted glass. I
am also using the 'direct sol inc' option for the switch control.