[TRNSYS-users] Heating Type Manager (Heating Load is too high)

[hotline]

Hey Asma,

did you take the higher air change rates in the WCs into account? Your supply air temperature is affected by the ambient temperature, so higher ach rates would lead to higher heating loads.
The boundary conditions seemed fine to me I think

Best,
Christina
________________________________
Von: TRNSYS-users <trnsys-users-bounces at lists.onebuilding.org> im Auftrag von David BRADLEY via TRNSYS-users <trnsys-users at lists.onebuilding.org>
Gesendet: Donnerstag, 26. November 2020 00:23
An: TRNSYS users mailing list at OneBuilding.org <trnsys-users at lists.onebuilding.org>
Cc: David BRADLEY <d.bradley at tess-inc.com>; Asma Sohail <asma.sohail at hotmail.de>
Betreff: Re: [TRNSYS-users] Heating Type Manager (Heating Load is too high)


Asma,

 Take a look at the ground floor boundary condition. Depending on whether you used the building wizard or not, the temperature of the ground underneath the slab can default to 0C, which often causes unrealistically high heating loads and unrealistically low cooling loads.

kind regards,

 David



On 11/25/2020 09:52, Asma Sohail via TRNSYS-users wrote:
Hello Christina,

thank you for the quick reply. Yes you're right, I'm converting the Qsens only from kJ/hr to W. I then enter the values ​​in Excel and divide my total heating load from a zone by the zone-area. I have a problem especially with the zone 15 and zone 16. These are interior rooms. An elevator and installation shaft (no heating on) is adjacent to these rooms. The elevator and installation shaft do not fall below a temperature of 15 degrees, so it's impossible that the zone 15 and zone 16 needs that much of heating power I get in the simulation. I even calculated the heat load manually. I don't know why, but I only get for interior zones a heat load that is way to high. There's somewhere a problem, maybe it's an easy problem, but I do not find it. I checked every link and the .b18-file but I do not find it. I also have to say, it's my first time working with TRNSYS. Perhaps the problem is in some setting I did wrong.. I hope really you could help me. Thank you in advance for your time, effort and help.

Best regards,

Asma

________________________________
Von: Sohail, Asma <st159047 at stud.uni-stuttgart.de><mailto:st159047 at stud.uni-stuttgart.de>
Gesendet: Mittwoch, 25. November 2020 07:25
An: asma.sohail at hotmail.de<mailto:asma.sohail at hotmail.de> <asma.sohail at hotmail.de><mailto:asma.sohail at hotmail.de>
Betreff: WG: Heating Type Manager (Heating Load is too high)


________________________________
Von: TRNSYS-usersIm Auftrag vonhotline via TRNSYS-users
Gesendet: Mittwoch, 25. November 2020 03:24:44 (UTC-12:00) Internationale Datumsgrenze West
An: TRNSYS users mailing list at OneBuilding.org
Cc: hotline
Betreff: Re: [TRNSYS-users] Heating Type Manager (Heating Load is too high)

Hello Asma,

I had a quick look at your .tpf-File and it seems that you are using the Qsens output from the building, converting these in the Equations "Q_sens" and then plotting them, right? The building outputs come in kJ/hr, so in the equation you're only converting them to W, not W/m². I didn't check the project in detail though, so i don't know if that accounts for all of the difference.

I hope this helps, let me know if it is a different problem.

Best,
Christina

________________________________
Von: TRNSYS-users <trnsys-users-bounces at lists.onebuilding.org><mailto:trnsys-users-bounces at lists.onebuilding.org> im Auftrag von Asma Sohail via TRNSYS-users <trnsys-users at lists.onebuilding.org><mailto:trnsys-users at lists.onebuilding.org>
Gesendet: Mittwoch, 25. November 2020 14:15
An: trnsys-users at lists.onebuilding.org<mailto:trnsys-users at lists.onebuilding.org> <trnsys-users at lists.onebuilding.org><mailto:trnsys-users at lists.onebuilding.org>
Cc: Asma Sohail <asma.sohail at hotmail.de><mailto:asma.sohail at hotmail.de>
Betreff: [TRNSYS-users] Heating Type Manager (Heating Load is too high)

Hello trnsys-users,

this is Asma from the University of Stuttgart. Right now I'm working at my diploma thesis using TRNSYS and a problem occured we were not able to solve yet. I hope that you might have a solution or an idea how to fix it. In TRNBuild I'm using the Heating Type Manager with unlimited power to heat a room to a  certain temperature (20°C). I'm only using convective heat. But something is not working properly with the simulation. I get a heating load that is far too high for certain rooms. Specifically, it is about interior rooms with a too high heating load. I've already checked all links or sources of error, but haven't found anything that causes an error. My maximum specific heating load should actually be around 40 W / m² (144 kJ / h per m²), but I get around 100 W/m² (360 kJ/h per m²), although the outside temperature does not fall into the minus range. It would be great if you had an idea
how to fix that or if you could identify the problem. Thank you very much in advance!! I attached the files I used in case you have time to have a look at them.

Thanks and kind regards

Asma







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David BRADLEY
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Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
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