AC Heat Pump use same drain pan?

[Acheron2010]

Sorry if this is a silly question.

When using my Dometic AC units as air conditioners to cool, I get condensate dripping normally through the two street-side drip hoses in the wheel well.

When I use the AC unit as a heat pump, no drip hose draining, but I get a steady stream of drips off the roof that finds its way to the door-side rear where the gutter rail ends, most probably the way the trailer is less than level.

Should the heat pump operation use the same AC drip hose?

[moosetags]

We have experienced the same "phenomena". We have always done a lot of Airstreaming camping in the cooler weather. We have noticed that condensation usually drips from one corner of the trailer.

I think what is happening is that condensation forms on the roof of the trailer outside of the pan. The aluminum roof surface is cool or cold and the heat pump is blowing out some warm air. When the condensation get to a sufficient volume, the water drips down to the low end of the Airstream. It could appear at any point on the trailer depending on how you are leveled up.

By the way, this is my totally unscientific assessment based solely upon long term observation.

Brian

[A W Warn]

Condensation occurs at different places when the unit is in different modes.

When the unit is in heat pump mode, occasionally it might run a defrost cycle to keep the outside part of the condenser free from ice buildup. When this happens the melted ice/condensate might run onto the roof.

This is just the opposite of when cooling mode is used, when ice/condensate builds up on the inside of the unit and drips out the drip tube.

[Acheron2010]

As they say, A-HA!

Thank you, Brian and Alan, for your wisdom and experience. Just love this board and all of you. The journey is safe and fun with you along for the ride.

[HHPJ]

2017 25a FC, and the exact same situation happens on the door side to... confirmation.