[Equest-users] Heat not working!

[Pasha Korber-Gonzalez]

Terry,

I took a look at your model file.  Here's a few things I notice even before
I could look at your heating systems.

   1. You file takes a REALLY long time to open--from observation you have
   way too many zones (think "thermal zones", not spaces.)  There is no need in
   a simulation model to simulate/zone each space individually.  You should
   combine thermal zones that are similar in thermal characteristics (i.e. same
   exterior exposure, same space type occupancy, etc.)  It makes the model &
   variables too complicated to manage when you are giving attention to very
   space in your building design.  For your sake, and anyone reviewing your
   model you should go back to the wizard and simplify your zoning patterns.
   This will help to reduce the number of inputs that you have to pay attention
   too as well.
   2. In your 3-d model view you have some spaces on the second level that
   do not have exterior wall constructions.  You may or may not have noticed
   the spaces with "white" walls or effectively no ext. walls.  Your sim calcs
   are not accounting for thermal & energy losses across these spaces, so your
   loads will be underestimated in the program and thus your overall energy
   consumption will be under-estimated.  This issue happens when you do not
   line your zone outlines up with your building footprint ext wall outlines.
   To fix the probelm you will need to go back to wizard mode and re-enter your
   zones for those spaces.  (I can talk you through this if you need assistance
   with it.)
   3. When I run the simulation you have results (energy consumption) for
   Misc. Equipm under gas consumption.  What type of equipment are you
   simulating for misc. equip. gas consumption?  Seems not right to me, but I
   don't know the details of your project...school & classrooms I assume.
   4.  Looking at your BEPU/BEPS reports you have 89% unmet loads.  Looking
   at the SS-F reports you have issues of underheating & undercooling, which is
   signifying that conditioned air is not getting to where it needs to
   go---what's blocking it?  ...I'm trying lots of things--(lesson:  don't be
   afraid to do experiments and test your inputs.
   5. For your undercooling try removing (undefine) your cooling
   availability schedule that is defined in the systems-cooling control tab.
   6. For your underheating, add baseboards at both the system level and
   zone levels, specify thermostatic (not outdoor air) and some amount of
   capacity at the zone level (like -50000.)
   7. For any other unmet hours you will need to experiment with your inputs
   primarily the schedules or controls inputs, this is likely where your unmet
   conditions are steming from.  Ask yourself what would contribute to cooling
   not being met in the space and then investigate the different inputs that
   might (or might not) affect the situation.  This is where the engineering
   analysis and scientist abilities come into play and can differentiate
   between any old energy model and a good quality energy model.  It is up to
   you to best represent what your client is asking for.

Good luck with the rest of your model, come back and ask more questions when
you come upon them.

Pasha


On Mon, May 10, 2010 at 6:57 AM, Terry Budd <terry at leesgood.com> wrote:

>  All,
>
>
>
> I'm modeling a building and for some reason I can't get the heat to turn
> on. The building is a VRF system - we are tricking a heat pump system into a
> VRF system per BSUG directions (attached).
>
>
>
> I've attached the model file. Can someone take a look and see what I did
> wrong?
>
>
>
> Thanks,
>
> -Terry
>
>
>
> *Terrence W. Budd, P.E., CPD, LEED AP*
>
> * *
>
> Lee S. Good Engineering
>
> 10483 Cleveland Ave NW
>
> Uniontown, Ohio 44685
>
> Phone: 330.494.1574  Fax:330.494.1567
>
> ü Please consider the environment before printing this e-mail.
>
>
>
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