I just came across this comment by coryatjohn in this thread that seemed particularly well related to temperature concerns.

"Another interesting thing to consider is if you have your pumps under your table, and they generate a significant heat load, they can actually change the precision of your table significantly, especially if the heating is uneven. Say you have your pumps at one end of the table and they get to 140f. That means there could be a 70 degree gradient over the length of your table. The change in dimensions of your table would be enough to be measurable."