Comfort tools

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Comfort Gradients

Are there other tools out there which are specifically developed to perform
only comfort calculations, PMV, PPD, etc.?

My understanding of the comfort models in DesignBuilder, ApacheSim
other energy modeling engines is that they calculate comfort only at the
central node of each thermal zone.

Is anyone aware of tools which calculate a gradient of comfort within each
thermal zone?

Thanks
Arpan

NYCCTgreen's picture
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Hi Arpan,

The CBE thermal comfort model can do this but may not be generally
available. http://www.cbe.berkeley.edu/research/briefs-thermmodel.htm

TRNSYS 17 with the detailed radiation model allows definition of
multiple comfort points in one zone and calculation of local comfort at
each point based on the operative temperature experienced at that
point. Air temperature gradients could be accounted for by defining a
single radiation zone with multiple air zones.

Regards

Erik Olsen, PE

Erik Olsen's picture
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Dear All;
Did anyone simulated a walk in cooler in a restaurant that he can share his experience, e.g. which software he had used and how he calculated the loads from the goods, was was the lighting load,
Thank you
H. Abaza

Abaza Hussein's picture
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Abaza Hussein's picture
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attached is a screenshot of the ashrae comfort tool output

Patrick J. O'Leary, Jr.'s picture
Joined: 2011-09-30
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Sounds impossible.

Information in bulk zone modelling is only stored at the node (typically
centre of zone) and on surfaces with no additional info in between.

There are too many unknown parameters to determine thermal comfort in
this way to determine a gradient.

You would have to use CFD which can be tricky without experience of
solar radiation modelling (depending on package used).

Tariq Abbas's picture
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I've heard that TAS can do this.

Julia Beabout's picture
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pretty much so if you're attempting to use to the ashrae comfort tools
to invidually "model" every space in a building. i am using it at the
system level only, more as a measure of setpoint/airflow to show a
compliance with ashrae 55 as the systems i typically work with are
simpler (i.e. smaller packaged units with not a lot of differentiation
in use met/clo per system).

the ashrae tool has its limitations but your question was about tools
that are specifically developed to perform only comfort calculations -
pmv, ppd, etc, - and that it does within the limitations of how it is
applied and what one is trying to use it for.

Patrick J. O'Leary, Jr.'s picture
Joined: 2011-09-30
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I don't think it can predict in zone gradients of TC.
TARIQ ABBAS BEng, MSc, LEED AP

Tariq Abbas's picture
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Hi Arpan,

What you described here is in the area of CFD simulation. You could not
expect an energy modeling engine provide you such data. Except for
ApacheSim, IES VE has a CFD module, MicroFlo, which can fulfill your
requirements easily.

Regards,

Cheney

chen yu's picture
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Thank you Cheney, I've used MicroFlo for ventilation studies, with regard to
comfort, how is MRT calculated, in your understanding with the limited
inputs.

Regards,
Arpan

NYCCTgreen's picture
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Hi Arpan,

You may have already known that the results, including surface temperatures,
from ApacheSim will be introduced as boundary condition into Microflo.
However, you can define the boundary condition yourself without referring
back to the ApacheSim calculation. I usually respect results from field
measurement more than those from simulation (My personal feeling is that the
simulation results usually are conservative in terms of estimating surface
temperatures). Using my recent simulation as an example, I increase my
boundary surface temperature from 20+ degree C (results from ApacheSim) to
40+ degree C (results from field measurement) and achieve more realistic
thermal comfort numbers.

So, back to your question, my premature thought is that, the method of
calculating MRT is not that critical compared as boundary condition which
will have significant impact on MRT. As long as a properly defined boundary
condition can be provided, MRT will be on the righ track.

Regards,

Cheney

chen yu's picture
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Arpan,

DesignBuilder CFD performs these calculations. You may want to look at it.
You can download free 30 days evaluation license of advanced CFD package
from our website:

http://www.designbuildersoftware.com/designbuilder.php

You may want to look at the introductory webinar posted at :
http://www.designbuildersoftware.com/db_support.php to see if it is helpful
in this project.

If you want to learn more about DesignBuilder CFD, we have one day webinar
coming up this Friday. The details are:

http://www.designbuildersoftware.com/Workshop-CFD-webinar.php

Please feel free to call or email you if you have any questions about
DesignBuilder CFD.

Best regards,

Mahabir Bhandari

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