I knew my rack would be in a 72-76 degree room so I used 12" wide THG tape in 15" long strips. This is on a 41qt rack and each piece takes up 1/3 of the floor space . This keeps my cool side in the high 70's and warm in the high 80's. You need bigger tape. Another tip would be to add a door on the front of your rack. You could also try a thick curtain to keep in the warm air. Ventilation then becomes an issue though.