I see this approach a lot in Lloydminster homes. I am not sure if only one or two contractors do this or if several contractors do it. My belief is that this approach is not a good idea as the trap will work to collect moisture but it will also freeze solid and block the line from venting. I have seen water traps under the insulation that keep the moisture in liquid form but most are hanging just above the insulation and are like a block of ice. My advice is to try to keep the vent short and as direct as possible to a vent in the roof. This way the moist air exits the house quickly and condensation levels are kept low. vent trap - full of ice