freitasm: Arghhh... We have an old DVS here (installed in 2001 apparently, way before we bought the house). We thought adding a tempervent would be a good measure, after all it heats up the ari being pushed to about 15c, which is a lot more than the air temperature outside during winter, so we can leave the DVS running without getting too cold.
Their agent came up saying they can't retrofit to specific model we have, so it would be about $2,500 to install a new model, a second vent and the two tempervents we want.
We decided to use $1,000 to improve our current ceiling insulation and put the difference into a heat pump.
Their loss...
And your gain! They really did you a favor, not installing a heater that would be constantly running wasting heaps of power. A heat pump is a much more energy efficient form of heating, and ceiling insulation is certainly worth the money. It makes me angry seeing inline duct heaters with 'eco' or 'econo' in the name.