We stopped by Aqua-Hot Systems in Fort Lupton Colorado and asked them to reviewed the Aqua-Hot installation in our 2006 36FDDS Alpine. Our main complaint was the very weak flow of hot air out of the vents in the bed pedestal. They quickly identified the problem "” the heat exchanger inside the bed pedestal did not have a cold air return vent. It was easy to demonstrate the difference with adequate cold air return by simply opening one of the access hatches under the bed. The hot air flow out of the bed vents was significantly stronger.
We added a vent by cutting a hole in the bed pedestal near the bottom center of the bed and now the bedroom heating is significantly improved. This location puts the vent nearest the heat exchanger under the bed, which they advised.
We didn't expect to run into the metal post in the center of the bed pedestal (oops!) otherwise we would have offset the vent to one side of the post. However we were able to trim our vent (from Home Depot) to fit around the metal post and by judicious use of black tape the metal post is no longer obviously seen through the vent.
The heat exchanger under our couch has ducting of wood construction which does not deflect the heat low enough to exit under the front. On cold nights we remove the front of the couch so the heat can get into the living area. This week we saw the 2009 34FDDS Limited SE and noticed that Western RV has solved this problem by using a special vent which attaches to the cut-out on the front of the couch.