unit issue: fixed heat flow rate per person

[veronikarichter]

In the UseConditions.json template, values for the "fixed_heat_flow_rate_persons" are stated. As described here, the unit of this measure should be W/Person. As a reference: The template states fixed_heat_flow_rate_persons = 70W/Person for a single office.

According to ISO 7730, the heat flow rate for a seated working activity is 70 W/m², where the surface area refers to the surface area of a person, where the conversion factor is 1.8. Thus, the correct fixed_heat_flow_rate_persons should be 70W/m²*1,8 = 128 W/Person, or the unit needs to be considered as W/m² if the value itself is not supposed to change.

My suggestion is, to keep the template as it is, but to consider the unit as W/m². Thus, for correct evaluation of the value, the template value needs to be multiplied by 1.8.

It is likely that we have to update all regression test results.

[DaJansenGit]

I don't know how you found the private repository of michael mans which is a fork of TEASER. For further reference please use the current development branch of TEASER on github which is the one we are using for our code.

But W/person is correct as you can see here

I disagree to use the value from template but interpret it as W/m² as this is really inconvenient and will lead to confusion in the future. If you want to use the value in EnergyPlus with the person area and thus the conversion of 70 * 1.8, I suggest to do so in the EnergyPlus Plugin part where you generate your model. Our Modelica models also do some further calculations with the base value of 70 W/person, like activity factor. So I would use the 70 W/person just like a base value and don't tinker with it inside the base core of the ThermalZone but only in exports to the specific simulation models.

Edit: I removed the bug label as this is no bug.

[veronikarichter]

I figured out that the fixed heat flow rate used in the teaser template bases on the German Standard DIN V 18599-10 (and that there is indeed no unit error in the template). As this Standard is written to calculate the energy demand of buildings (for energy efficiency ratings) but not for actual load calculations (used for further dimensioning of HVAC systems), these values are not suitable for any kind of more detailed simulation (e.g., evaluation of thermal comfort). I would recommend developing an improved set of templates that bases on standards for system sizing.

The VDI 2078 states calculations for heat emitted by occupants. DIN EN 16798-1 states input parameters for system sizing.

In terms of international standards, for modeling the internal occupant gains the ASHRAE Fundamentals could be used (Chapter 9 and Chapter 18):