I think using NTYPE 25 is actually more precise, as it seems to
use variable exchange coefficients (the formula is in the manual 5).
I guess NType25 was not available when we had this discussion,
so I guess using it is probably better than writing the formula (which was
mainly used to show the basic idea).
Werner
De : Kent Beason
[mailto:kbeason@schlitterbahn.com]
Envoyé : jeudi 18 février 2010 15:36
À : keilholz, werner
Objet : RE: [TRNSYS-users] Simplified heating and cooling
basedonoperativetemperature
Werner,
Does this approach give a different result than that which the
NType28 provides from the Type56 outputs?
Kent Beason
Schlitterbahn Development Group
830-609-8904 m
From: keilholz, werner
[mailto:werner.keilholz@cstb.fr]
Sent: Thursday, February 18, 2010 8:18 AM
To: Sabine Jansen - BK; Maarten Sourbron; trnsys-users@cae.wisc.edu
Subject: Re: [TRNSYS-users] Simplified heating and cooling
basedonoperativetemperature
I once proposed to define an equation
:
(using the definition from Wikipedia)
tr
mean wall temperature;
ta
mean air temperature
ts
mean skin temperature
and link it to the building as in the
attached picture.
- In
TRNBuild, add all ‘wall temperatures’ as outputs (yields tri,
for i 1 to n walls)
- Add an
equation to compute
, then T0
Estimate v (wind speed) and ts (skin temperature)
- Connect
the result to a controller which pilots the heating in type 56 in mode « temperature
level control »
But I agree it would be much nicer to have
a switch in type 56 allowing computing based on operative temperature.
I’m not at all an expert in this
domain, but my expert colleagues never contested the approach J
(except for the hint that the mean surface
temperatures should also be scaled depending on the surface area to be
precise…).
Werner
De : Sabine Jansen - BK
[mailto:S.C.Jansen@tudelft.nl]
Envoyé : jeudi 18 février 2010 14:51
À : Maarten Sourbron; trnsys-users@cae.wisc.edu
Objet : Re: [TRNSYS-users] Simplified heating and cooling based
onoperativetemperature
Dear all,
I
am also interensted in that question.
The
only way I know now how to solve this is by using a type (controller, type 2 or
thermostat, type 8) outside type 56. The the operative zone temperature
must be connected to this type (e.g. 2b and creating a schedule elsewhere, in
an equation solver), and the heating must be defined as a limited power connected
to an input, which is then the output of the control type (type 2 or type 8).
One
problem with this approach is that I cannot use a very large heating power
anymore, since that causes the controller to switch on and off. Thus the
heating power must be determined using the ideal heating, based on air
temperature, first.
If
there is an easier way, I am also very happy.
Kind
regards,
Sabine
Jansen
Van: Maarten Sourbron
[mailto:Maarten.Sourbron@mech.kuleuven.be]
Verzonden: do 18-2-2010 13:53
Aan: trnsys-users@cae.wisc.edu
Onderwerp: [TRNSYS-users] Simplified heating and cooling based on
operativetemperature
Dear all,
The simplified heating and cooling in Trnbuild is now comparing the zone
AIR temperature with the given set points. Is there a way to change
this (or another controller model) to have the zone OPERATIVE
temperature compared with the set points?
Kind regards,
Maarten Sourbron
--
Departement Werktuigkunde-Department of Mechanical Engineering
Katholieke Universiteit Leuven
Celestijnenlaan 300A bus 2421
3001 Heverlee (Leuven)
T : 0032 (0)16 32 28 73
F : 0032 (0)16 32 29 85
E : Maarten.Sourbron@mech.kuleuven.be
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