This is a nice change we very recently made to our RV’s ducted heat system and was so simple. We removed and replaced the washroom’s terminal louver with this new one. The former one swiveled to change the direction of heated air. The new one both swivels and has a damper knob on its face.
Even as much as we try to chase 75 degrees, it seems we often are outside that comfort zone. Our air heat system performs two jobs, it heats the living space and warms the holding tanks. The holding tanks should obtain some freezeproofing from this latter function, if we stayed in a sub-freezing climate more than a day or two.
The ducted system seems to have had no intentional air balancing. The heated air pours into the washroom far more than the room needs, especially since we spend the least time in the washroom. The new diffuser allows us to select the volume of air to the washroom and therefore we can increase the volume to the more oft used spaces.
Little changes, all added together, make our home fun to tweak and maintain. Maybe we are improving it. Or at least, we are customizing it. This was an inexpensive ($5?) change, easy to install, and it actually works as we imagined it would.
This is one of those aha moments that you sometimes just stumble onto. We weren’t looking for it. The air volume design (or accidentally achieved) into the bathroom was so excessive it was stupid. I imagined installing a slot damper inline in the duct under the lavatory. Then we saw this in the Airstream factory store. Aha!