How to get indoor temperature for basement pre-processor?
Hi all,
I'm using the basement preprocessor to model the ground heat transfer for an existing small building in Energy plus. On the input parameters, I have to input Indoor temperature every month, so that the preprocessor can estimate the heat flux.
How shall I obtain those indoor temperatures?
I have tried running the model with two sets of monthly mean air indoor temperatures: 1) Obtained from a preliminary run considering the surfaces in contact with the ground as adiabatic. 2) Obtained from a preliminary run considering a simplified ground temp of 18ºC
I am comparing the resulting zone temperatures of the simulation with temperature recordings we made in the building (unheated), but none of the options seems to get close enough to give us confidence. One option shows consistent 3-4K above, the other is some 3K below.
I've checked E+ documentation and the Ground heat transfer manuals but it didn't clarify this. Thanks, Rafael
Have you considered using Kiva instead? This doesn't need a preprocessor step in your workflow like the basement or slab tools.
Hi Aaron, Kiva has been on my to-do list for a while, but I never manage to make time and get my hands on it. Since we have automated part of the idf syntax for the Preprocessor, we always find it faster to rely on it.
For the medium term, entirely agree that Kiva would be the solution. But I´m still hoping to find an answer for this one.
Are the 3-4K differences in zone temperatures at an hourly frequency, or monthly average, or something else? Having the preprocessor calculate hourly loads from a monthly air temperature will make it difficult for hourly model results to match hourly recorded data.
The 3-4K difference was in hourly temperature. We just realised we were comparing Zone Operative to Ambient air recordings which is not really comparable. Comparing Zone Mean Air output to the Air temperature recordings shows values that are much closer, below a 0.5K difference. Solved, apologies Aaron for the initial confusion.
Ah! Cool, no worries and I'm glad there was a solution.