Thanks. I have those little felt pads for under chair legs on the top one. Was hoping that 1/4" air gap would be enough to minimize it. I will keep and eye on the floor of the top cage and see if I need more separation. I gave myself a month to get the tweaking in so I should have plenty of time to get it all figured out. I bought the dual zone VE thermostat so I only have one unit to work with and it was cheaper then buying 2 separate ones. I have it set to proportional.