I am using 3" in a rack and the room is kept at stable temps with a heater. I have my flexwatt more towards the back which is all enclosed. I'd say maybe 1/3 from the back of the tub is about where I have it. The temps are good in my tubs but I also have a layer of material over the flexwatt that helps spread the heat some. I was thinking of using larger sized FW in a new rack but as said above with a room at a good temp you may not need to cover as much area to achieve the desired hot side temp.

I'm interested in what others have to say and what works for them. The cool side temp should be considered in the setup, having to much FW could cause the cool side to be warmer than it should be. I'd be interested in other configurations such as:

hot < cool
hot > cool
hot = cool

meaning you have more hot side than cool side or vice versa or you try and create equally hot and cool sides.


Edit: I'm going to make this question a poll