I have a rather long house and I find my HVAC system is all over the board in terms of individual room temperature and I would like to "balance" my house so it is consistent. I was thinking that ductwork could be controlled using some sort of rotational valve, temperature by individual sensors and airflow the same. I figure this can all be done through a smartphone or tablet. Has anybody here had any experience with this type of system and if so, does it work well and how expensive is it?

 

Why not fix the real problem? Like why your HVAC is all over the place in certain rooms..
poor insulation? inadequate returns? ,etc...

 

Zonal control with remote will likely cost more than you want to bother with. It's cool, but not so much once you're tired of playing with it.

If you can identify specific causes for one room going out of control, such as sunlight, closed or inadequate vents or returns, then you're money may be better spent on shades, attic fan or the like.