We are in the process of installing a 3.5 ton carrier water cooled heat pump in a ceiling.The unit is just a bit over the drop ceiling.Went to finish hooking up the drain line from the pan, and realized I dont have enough room to make a trap.We are using clear vinyl tube to provide some vibration elimanation.The drain will terminate in the basement below into an open 3" standpipe with a 1 1/2" trap on the bottom.Any thoughts are appreciated.Thanks.