Radiant time series method for ground modeling?

edit

Hello all,

I'm trying to wrap my head around building heat loss of a building through the ground, and there are a few ideas that I'm confusing or mixing up.

Firstly, my goal is to a spreadsheet where I can calculate cooling loads of a building, and compare to simulation results from EnergyPlus. I have good results for walls, roof, and glazing, plugs loads, occupancy loads, and lighting loads, but ground loss is turning into a real challenge. I'm fairly comfortable with the non-ground elements, and used Slipstream's Back-of-the-envelope-Calculator and ASHRAE's RTS spreadsheets.

From here I'm trying to apply the same methodology to ground losses. Now I have seen some of the conversations here on ground modeling and I understand it's no simple as to apply other methods to ground modeling. I've tried Kiva and it gives me a roughly consistent value that is not represented in my EnergyPlus simulation results.

So, does anybody have any experience with CTS/RTS/Sol-Air calcs for slab-on-grade ground modeling?

Thanks.