I have a 2-stroy house that I want to zone, upstairs & downstairs, because currently the whole house is one zone. I have quotes to have dampers put into each supply line (16 total, 8 on each floor, all 6" lines) from 2 different contractors. One guy wants to use Arzel pnuematic dampers and another wants to use EWC electric motor dampers. Which way is better? Pneumatic vs. electric motors? Arzel vs. EWC?

Any thoughts or experiences would be great.