I'm confused with the following results on my model,
1.) how the absorbed solar radiation value in the component relate to total calculation/heating period heat gains as it uses a unit of Wh/m2 and what is the use of total calculation time/heating period in the component results. (see picture attached---solar radiation on component).
solar radiation on component.jpg (76.91 KiB) Viewed 6710 times
2.) how the heat gain/loss calculated (Kwh)? because some of my component like heavy construction wall with insulation had a quite high heat gain. (see picture attached---heat gain_loss).
1.) the shown absorbed radiation (per square meter surface area) is related to the total calculation. It directly influence the transient hygrothermal behavior of the component. The absorbed radiation on the outer surface is not regarded as heat gain for the zone result (but of cause, may indirect if there is a heat flux to the inner surface). Instead the absorbed radiation on the inner surface. This radiation comes from the zone and is shown as heat gain (solar radiation via transparent components, inner radiant heat sources) within the zone.
For the heating period only gains and losses are surmised if there was heating power necessary to keep the inner climate within the design conditions.
2.) This shown gains and losses are related to the inner surface of a component, influencing the inner zone climate. So if you "Retain the calculation results" for a component ( the check box in the result tab) you can store the heat fluxes (per square meter surface area) per simulation time step. If you sum the positive values (the gains regarding the zone) and the negative values (the losses) and multiply the values by the surface area you should get these values for the total calculation period.
Yes, I found how the figures came out in the total calculation period and heating gain period as your above instructions. A big thank for that. But anyway, to complete my work in my project, I need to clarify the following;
1.) the picture below is the result of a roof component exported from the calculated courses. I need to know how to calculated the Inner surface Heat flux (W/m2) to support the heat gain/loss results. I have tried various formula's from H. Kunzel reseach -"one and two dimensional calculation using simple parameters" (i.e. equation 43 and 27 -second attachment , 29 and table 5-third attachment) but no luck. It's a big help if you can show/give me one example incident in the picture below (marked in red) came up with that heat flux (marked green).
picture of results.jpg (118.21 KiB) Viewed 6684 times
heat flux_formula_1.jpg (25.3 KiB) Viewed 6684 times
heat flux_formula_2.jpg (37.92 KiB) Viewed 6684 times
2.) How to find the heating power for each time step? Do I have to base on the heat flux of all the components?
1.)
the heat flux on the is calculated with a kind of equation 29 in your second attachment (heat_formlua_2.jpg). But instead of the heat transfer coefficient (alpha) the heat transfer resistance (input parameter in the surface->thermal Tab page) for the exterior or interior surface is used. The equation is:
q = (-) 1/Rsi *(Inner air temperature - component inner surface temperature)
regarding the heat flux for a component defined from outside to inside to be positive.
I presume that your results not show the surface temperature of the inner surface (..., 0,124cm). this lenght represent the depth in the layer. I think this point is insde the component.
2.)
you find the heating power each time step per zone in the heating /cooling graph (in the results for a zone). You can export the "heating power" time step values if you select the case in the project tree, in the Results->Export Tabs. However, the heating power is only calculated if you have a (ideal) heating system defined for the zone, to keep the inner climate at the minimum design temperature.
Thank you for the information above, I found exactly the result. Anyway, I have one more question, I'm looking on how to solve the inner surface temperature of the succeeding time steps as it is the only unknown on the formula in jpg. no. 29. Thank you.
