Where to get Ground temperature values
Hi, this question is less aimed at the software and more on where I might be able to find ground temperature values.
I am able to use the measures SetGroundTemperatures:Monthly and SetGroundTemperatures:Constant in OpenStudio. I unfortunately have a hard time looking for ground temperature values to input, so I am asking if there are any viable ways I can get this data myself? OS uses the default value of 18degC, for context the site is located in the Philippines, and I don't think that's a realistic value for the tropics.
Do I go to the site and use an infrared thermometer on the ground itself? I am not aiming to look for the temperatures at different depths, as the OS measures only ask for average-monthly or even constant values. I just would like to know how it is usually done for a case like mine.
I have read FCFactorMethod and KIVA being mentioned in a few forum posts, but I am not at all familiar with them and don't know if they can be applied to my project.
If possible, I would much prefer if there are any reliable sources for this, as opposed to rule-of-thumbs, as I would like to cite them in my paper. If anyone can direct me to studies or methodologies regarding this that would be a huge help!
General recommendations, as echoed in the IO Reference. Monthly ground temperatures (adjacent to surfaces) depend on: depth (slab-on-grade vs basement), soil saturation/irrigation, internal loads, cooling/heating setpoints, etc.
IMO, there's no reason you couldn't use KIVA instead.
@denis-bourgeois My building is unconditioned and doesn't have a basement, how should I start with KIVA? Slab is also mentioned in the reference, do these do the same thing? Thank you.
@mther, Slab is an auxiliary program one runs using the run/in.idf file (generated by OpenStudio) as input. "Option 2 - Average Temperatures" describes what you're after. Instructions here.
As suggested elsewhere (e.g. here), you may want to drop the idea of setting monthly ground temperatures altogether, and instead rely on KIVA to update prevailing ground temperatures at runtime. Here's one way to access/set KIVA using the OpenStudio Application. Hope this helps.