What is the best way to handle unconditioned spaces in eQUEST? Right
now, I am zoning it separate and calling it unconditioned in the WIZARD.
Then, when I assign systems, I am putting the unconditioned zone in a
system with a conditioned space and saying " one system per floor". Is
this the proper way to do it?
I have tried just leaving the zone as unconditioned and on its own, but
then when I do the "permit submittal" calculation it still asks for the
fan flow and cooling capacity for that zone.
Amber Welsh, P.E.
Amber,
If I?m following your description, you must be specifying the unconditioned zone in Shell Wizard/Screen 2/Zone Characteristics button. Then you?re obviously specifying system-per-floor in the HVAC wizard. This sounds like it should work, but what is happening is Shell Wizard/Screen 14 settings are trumping Shell Wizard/Screen 2. There are two solutions:
1) Simply change the zones to unconditioned in the detailed interface.
2) Create a new zone group in Shell Wizard/Screen 14. Assign the unconditioned zones to this group, and then make sure the ?Conditioned? check box is not checked. Assign the group to whatever system makes sense and move on (making sure that at least one conditioned zone group is also assigned to that system). All zones have to belong to a system, but if they?re unconditioned their parent system is irrelevant. This method is only slightly longer than the one above, but it lets you stay in the wizard.
If you try to leave an unconditioned ?on its own?, which I interpret as being assigned to its own single-zone system, you?ll get an error saying every system has to have at least one conditioned zone. Let me know if I have misunderstood you.
DAKOTA KELLEY
Maybe I was too vague in my reply.
I, too, was hoping for some insight into this particular issue.
While I do believe this to be a software (developer) oversight, I also
believe that any offered solution(s) to such a 'problem' could be handled
with slightly more dignity; perhaps even some humility!
It is more likely that 'this' is a software issue more than anything else.
Hopefully this, and many other issues, will have been addressed in '3.6.4'!
It makes absolutely no sense to me to assign a system to 'unconditioned
space' that is being used to 'condition', condition space. Since every
'space', or zone requires the assignment of a specific mechanical system,
then wouldn't it be likely [as in the 'real world' vs. our 'virtual' one, be
equipped with 'NO" system since it is 'NOT' conditioned, versus an
'operable' system that supplies conditioning to a space that requires such?
While it agreed that all zone 'must belong to a system', I'm not convinced
that your [emphatic] solution employs the ideal method for addressing such
an issue. It seems to me that you're placing her back to the same point in
which she came to discover such a unique condition.
Looking forward to a legitimate response!
Sincerely--
John
Hi John,
My perceptive powers are not the greatest, as my wife will assure you,
but I'm failing to see the reason to get any feathers need to be hackled
here (I did miss your reply, perhaps it wasn't copied to the list?)....
The reality that DOE2 has a "no child-zone left behind act" of sorts is
just the nature of the beast, and nobody is arguing that's unintuitive -
it's simply something we have to learn as we become familiar with the
engine. I don't know that I'd expect this issue to be resolved in the
next major update as it's something a user can work around (unlike some
other more pertinent issues), as Dakota is plainly demonstrating with
his (typically) thorough response.
Everyone is here to help each other, rest assured (^_^)b, those who
aren't don't stick around long, and Dakota's certainly been around for
awhile! If you have a "more correct" or otherwise better solution to
handling unconditioned zones before or after the wizards, I would
personally like to know also - I do the same as Dakota. I understand
others simply ignore the zone grouping wizard screens altogether (though
I find them to be quite a time-saver), so his inclusion of "simply do
this" in detailed is very appropriate to the group at large...
Wishing everyone a safe and happy weekend,
NICK CATON, E.I.T.
Nick,
You are absolutely right! My (so-called) feathers get ruffled way too
easily, which is why I make a conscieous effort not to comment in here
unless I'm 'mostly' confident that my contributions could even
potentially benefit someone encountering a problem similar to one I've
encountered in the past. Such constraint on behalf of all contributors
would do wonders for such an environment. The quality of query in
which I witness here for the most part is astonishing. (i.e. 'how do
spell equest'?). Rather than doing the research on their own, or at
the very least, exploring the 'onebuilding' query history, this
platform makes it all too easy to ask the infamous 'stupid question',
though I realize there exists no such thing.
I am beginning to believe that Carol is right in suggesting a more
professional and reliable authority to more acurately respond to user
querries. And someone else who suggested an eQUEST-wiki might just be
spot on. Thought I will admit, in an age where electronic response has
become the norm, there is certainly something something quite a bit
more 'personal' about receiving a reply from a beating heart.
As such, it is my feeling, that any 'responder', should not respond so
specifically so as to ignore the larger question an inquiry might be
addressing, particularly when a prior responder has already replied
and explicitly requests additional input on his offered solution.
In the spirit of community (as you have suggested) I would challange
anyone who posits a potential solution to address the formal issue at
large, rather than simply offering his(her) two-cents in contrast
simply for the purpose of seeming 'right'.
To do so, I am sure, would more likely benefit the group as a whole.
John Waller
Sent from my iPhone
Boy, I guess it's been a long week for many of us. Since my name was brought
up I thought I'd chime in. Thanks for the shout out, John
I was reading this email chain and thanking my lucky stars that I learned
how to do this stuff back before dirt was invented and you had to enter your
input deck line by line using BDL. It gave me a pretty solid background as
it turns out.
It seems to me that some of you guys are spending entirely too much time in
the Wizard doing things that might be able to be done easier in the DDedit.
I know I've said this before. For instance if you think of an unconditioned
zone for awhile you realize that it really doesn't matter what system it
gets attached to, its unconditioned. You will see on your SV-A report that
there isn't any cfm for it or any load. If there is you are doing something
wrong. I always makesure that the space and the thermal zone are both
labeled "unconditioned" because I don't trust eQUEST for a minute if there
are inconsistencies.
So back the the utility of having a "reliable authority" dedicated to
answering questions on this site. While I can't claim entire reliability, I
ran across something last week that really had me trembling with
trepidation, sorry it's Friday night after all, related to eQUEST.
If you'll remember I asked a question about EIR curve fits last week to
which I received a resounding non response. I'm pretty sure I know why and
it's probably bad news for the results we are giving people. I don't think
people really know how to do curve fits properly. I know I learned something
new as I researched and researched every where I could think of to find the
answer. And even then I had to make a desperation call to one of the few
real experts.
Some background on the problem: all curves using raw data need to be
normalized around ARI data points except for refrigeration compressors, see
Volume 2r written in 2008. So if you are entering a curve, say the cooling
capacity as a function of the entering wet bulb and the outdoor dry bulb,
you would have three lines of data: 2 independent and 1 dependent. The
independents would be your selected wet bulb temperatures and your selected
dry bulb temperatures. You are allowed to enter up to 20. The tricky part is
when you specify the dependent value: the capacity. The person who I am
helping with this model had simply entered the capacities as they varied
based on the temps: 307 kBtu, 299 kBtu, and 292 kBtu (the ARI capacity),
etc. [Note: I'm just making these numbers up.], and didn't normalize them
around the ARI data point capacity. If they had the numbers would have been:
1.051, 1.024, 1.0, etc. And the file ran with no indication of an error
anywhere. I've seen this over the years in some surprising places. It scares
me because I don't know how the results are being effected. I guess no one
else does either because I haven't heard anyone saying anything like "hey I
entered bad data into eQUEST and it ran" or hey the LEED reviewer said XX,
fill in the blank.
Anyway, back to the EIR curve-fit. With further research I found the actual
equation that is being used in eQUEST which are EIRt = Cooling EIR *
Cool-EIR-FT (EWB,ODB) * Cool-EIR-FPLR (PLR). That's when I asked my question
to you all: what equation type do I use when there are three independents as
there seem to be here - EWB, ODB & PLR. No answer. So I placed the call and
was told that eQUEST solves the equation using 2 curves: the EIR varying
based on the EWB and ODB, normalized around the ARI EIR as discussed above,
and the EIR varying based on the part load conditions. I didn't know that
before because I usually can avoid curve fits. In this case, however, I was
modeling a VRF system so it's pretty much required since they are not like
the current systems that are accessible to us. Luckily I had really good
data from Daikin, although it took awhile to get it. I was modeling European
units, too, just to further complicate things.
Anyway, lesson learned. Sorry to be so long winded, I kind of reminded
myself of Nick here. Sorry, Nick, just kidding! Your answers do lean towards
being thorough, though, but that's good. You have a great knowledge of how
to use the Wizards as well as the DDedit. I think that in this case, though,
my past experience of entering the line by line BDL really helped me. When
we had to do that we had more time to think about how and why we were doing
things and generally more access to the engineering formulas behind it all.
With the friendly front ends we have now, and make no mistake I love them,
modeling has become more of an art and less of a science. This is both good
and bad. It's why I think that there is room for having a dedicated,
experienced resources person for eQUEST as well as the users of this
listserv. There's a lot to know and it takes time to learn it.
I rest my case.
Carol
Carol - wow! Your verbosity makes me so proud... I managed to learn
something darn useful to boot, thanks!
John,
I fully agree that there's a fluid line of professionalism and expertise
in this body of respondents, and I suppose that's likely inherent to any
resource without a paid staff. In some ways, it's a real benefit as you
can get feedback from so many perspectives. Many of us are
"self-taught" in the sense that we've had to come up with our own way of
getting various things done - and it's always a benefit to the group
when we compare notes... Just as the seasoned veterans will share "tried
and true" means and methods, so do the less-experienced
discover/stumble-into innovative ways to approach a problem that may
save those veterans time and frustration.
As someone on this list once advised me, sometimes the best way to ask a
question is to deliberately give a wrong (!) answer. I haven't
exercised any intentional mis-information, but I do respond with partial
answers as I can, and make clear what I don't know. This approach often
elicits responses from otherwise apprehensive individuals containing
their own experiences and insights. People are more prone to provide a
partial response once the ball is rolling, so to speak.
The "quality of queries" on the lists ebbs and flows over time with
regard to the degree of sophistication and effort on the part of the
poster. Every once in a while, new subscribers need to be reminded of
the implications this voluntary list entails... In order to get the
best response, they must recognize a degree of courtesy,
professionalism, and background knowledge as prerequisite to others
being inclined to volunteer their time to help out a total stranger.
People sometimes don't realize this is an international body of
subscribers, and an email spell-check/proofread can be very helpful when
asking a complicated question - sometimes attaching a representative
cutsheet or your project files is the fastest way to begin discussing a
topic... stuff like that.
The "quality of responses" on the other hand is something that is
terribly easy to take for granted. Any response to a query on this list
is ultimately one individual lending their time and experience to help
another. Personally, I choose to contribute partial answers where I
don't have the time to address an otherwise broader question. Sometimes
it's impossible for the asker to know that a question is actually very
broad, and it's most helpful in the short term to point this out so they
may "narrow" their question. Other times, it's most helpful, even if it
appears blunt/rude, to direct a questioner to "read this" or "look the
answer up here" ("teach a man to fish..." as the saying goes).
Also, it's a common situation to see one big email with a series of
questions (of varying breadth/complexity). When listed or bulleted out,
it becomes easier to respond to the whole post, but ultimately such
posters should anticipate they may receive partial answers to the
posting. For example: Perhaps I feel I have the time to respond, but
only know a complete answer to 4 out of 5 questions... should I not
respond at all? Extrapolating that line of thinking to the everyone -
perhaps nobody would respond to that post. I'd rather encourage anyone
willing to contribute to definitely share what you know, and don't feel
pressured to know everything - others on the list can "fill in the gaps"
as may be necessary.
This branches into an elephant in the room - questions are certainly
posed that nobody knows the answer to, indeed with no solution! As long
as it has been around, the science/art of building energy modeling still
seems (to my young eyes) a fairly bleeding-edge field of study and
practice. Students and other end-users getting their feet wet in this
skillset should recognize coming in that it's not unheard of to run into
a question nobody has explicitly asked before! This is where the
partial answers, experiences and open suggestions available through a
'meeting-of-the-minds' in venues like the onebuilding.org lists can be a
key resource for one's own search for a solution (delving into google,
DOE2 docs, digging in the archives, etc). Such queries are where a
community like this really shines over the potential for any support
department/hotline.
That said, an expert staff of compensated, full-time eQuest/DOE2
answer-givers would certainly be a welcome thing, but it would be a
complement to (not a replacement of) the function of this existing
community at-large.
In light of the context, I'd like to avoid saying that's my two cents,
but there you have it =)!
NICK CATON, E.I.T.
I agree with Nick on all points in this email. I would add the old saw "in
order to ask a question you already know the answer", and it's corollary,
"you don't know what you don't know". WRT to the first old saw, if we
remember it when in the process of posing a question to the group we might
just find that we can answer our own question. WRT the second old saw, this
is the one that scares me as I have shared before, because I know there are
mistakes being made even by experienced modelers and no one, even the LEED
reviewers, I suspect, knows they are there either. A person working at the
level of finding and sharing these errors and their solutions would be the
person who needed to be paid.
Any ideas?
Carol