Ceiling register vs difuser

[radstorm]

Greetings all;

I am planning to run new duct work throughout my home, and I am trying to figure which was is best to go.

My house is small, and the rooms are mostly 10x10, 10x12. I have been told by some using round diffusers are better located center room, and others say go with register vent.

Also is flex duct ok to use? ..I hear pros and cons on that too. I guess the main pro is easy installation.

Some rooms have small windows, other have no windows at all.

My furnace is electric, and horizontal flow in the attic space.

Any suggestions?

Thanks

[HayZee518]

heated air by any means stratifies to the ceilng because heat rises as you know. registers in the wall create convection currents to heat a room while ceiling diffusers distribute heat at the ceiling level. eventually the heat will make it 'round the room but for the most part is inefficient. if you have the means install wall registers and have at least one central space where the makeup air can travel back to the heat source [furnace] to be recycled.

[radstorm]

Yup I got a lesson on heat rising first time I ever saw a hot air balloon The problem is however my walls are concrete, so I am pretty much confined to overhead venting. There is no way I will start tampering with my walls and weaken my structure. I kinda like it being a bit wind proof. Also as far as flex duct, is is wise to go up one size compared to metal duct? Right now most of my ceilings are tore out as I am replacing the old plaster with drywall, so I have pretty easy access to the attic space.