insulating rack systems?

Hello,

I was wondering if anyone has come up with a clever trick to help retain heat in rack systems.

I use 16 and 32 qt boaphile rhinorax with 4 in wide flex watt for my BPs and as the ambient temps have been going down in my home I have become progressively concerned about the ambient temp in the racks at night.

Heating the whole room isn't an option for me because I have a large reef aquarium that tends to overheat if the ambient temp gets too high.

Currently, I've been partially covering the front of each shelf of the rack with a section of the pink foam board used to insulate houses. This helps to some extent but isn't keeping things as warm as I think would be ideal. On cold nights, my ambient drops to the mid-low 70's.

Another tick I have used is to make a hide out of a cardboard gift box that covers about 2/3 of the cage bottom and is about 2" tall. This creates a large warm hide with a thermal gradient.

Any other tricks you guys use? As I mentioned heating the whole room really isn't an option. If I cant warm things up a bit in the rack, I may move the rack to another room.

Place a blanket over it.

This simple solution seems to have worked well. It's hard to tell because the temps seem to have warmed up outside.

I draped a down comforter over the rack in a way tha covered three sides and about hald of the front.

I also put closed empty 1 gallon water bottles on the unused shelves to try to keep warm air in place.

Looks like its maintaining ambient temps about 5 degrees warmer.