Air carrier Captain reported the NOTAMs at IAH regarding cranes near the runway are confusing and make it difficult to determine the minimums and approach capabilities.

Narrative

There are some confusing and conflicting construction-related NOTAMs at IAH. I'll use ILS 26L in my examples; but I see the same for other approaches too.NOTAMs 1 and 2 reference a crane that's 5794 feet west of the runway. These NOTAMs make changes to the minimums and approach capability; except when advised that this crane is down.NOTAMs 3 and 4 also reference the crane that's 5794 feet west of the runway; but in addition they reference a different crane that's 5937 feet west of the runway. These NOTAMs make different changes to the minimums than the ones mentioned above; and these NOTAMs do not allow any exception for when the crane(s) are down.Finally; NOTAM 5 says a crane (which one?) will be lowered during certain approaches to 8R. It makes no mention of approaches to other runways; and it also appears to reference another NOTAM that I can't find.So... Is the crane down or not; which crane are we talking about; which NOTAM do we use to determine adjusted Category I minimums to ILS 26L; and which NOTAM do we use to determine if we can do a Category III to 26L?On this arrival the weather was variable at and below Category I; so we briefed the Category III to 26R (no NOTAMs; no confusion). Upon transfer to Approach; they said to expect 26L. Based on the above and not wanting to get into a protracted discussion on the radio; we just declined and stuck with 26R. However; multiple other company aircraft were executing the ILS 26L; apparently without regard to the NOTAMs.This is a large hub. Given the number of flights per day and the length of this construction project; I can't believe nobody has noticed these discrepancies.