I actually looked into this myself the other day. It seems like the instructions frequently mention 103 - 130 C as the temp you want to hit, for about 8 hours, some have suggested 12 hrs at a low temp.
So, living in an apartment, smell is a thing I'm trying to control. So my next best plan was to buzz up the weed to powder, toss it in one of my small mason jars with a measured amount of coconut oil, and throw it in the crock pot on top of a roast and leave it for about 8 hrs. Just let the fucker cook all damn day. Once the roast is done, maybe just take the mason jar out and do a little double boiler situation on the stove with light heat for the remaining hours if it hasn't finished just yet. It's my understanding that it browns slightly when decarboxylated, so I would imagine a color change would be a decent indicator of completeness? Anyway..
I've heard frequently that people use the crockpot to do huge batches of coconut oil infusion, I wouldn't even bother filtering out the solids seeing as it's being eaten anyways. Some of the unit conversions I was given were:
The bud weight x 0.2 to approximate the mg dose of THC per unit volume (10 grams = 2000 mg THC, or 1 gram = 200 mg THC, just for some numbers to work with dose wise)
And obviously write down the weight of the coconut oil added.
Do a ratio conversion to figure out what volume (or weight) of CC oil = what dose of THC (weight of oil / {bud weight x 0.2} = volume to mg ratio), also I was told about 20 mg is a typical dose, and using the conversion given that works out to about 1/10 th of a g I think.. I'll have to actually writ some shit down.
I'll try out the equivalent of 5 - 10 mg, since I'm a "one puff" kinda guy, and that corresponds to 1/40 to 1/20 th of a gram of herb. Ya, 20 mg would be 1/10th... because 20 x 10 is 200, and 1 gram of bud is about 200 mg of THC using this crude conversion.
If there is a simpler way, I haven't found it yet. Also, I haven't tried this yet but I suspect it should work just fine seeing as people use the crock pot pretty regularly for this, having everything sealed in a separate jar inside the crock pot would fix the smell issue and make use of the rest of the heat, instead of running a whole crock pot for one tiny mason jar with a half cup of oil and like 11 grams of bud.
Thoughts?