Does anyone know how to do duct designs?

[Rookie]

I had planned on replacing my a/c unit later this summer. As luck would have it, it is officially dead. I'm going to replace almost everything, the flex duct will stay. This is an attic install, but I don't think that makes a difference.

I need a duct layout. Every run is eight inch runs. I know that's not the best, but, quite frankly, I'm too fat to change them out.

So, anyone willing to give me a duct design?

 

[Kirk Freeman]

 

[Rookie]

Well THAT was helpful. You should probably think about a new career, HVAC is definitely your calling.

 

[Rookie]

Btw, someone needs your help with air compressors...

https://www.indianagunowners.com/fo...1-anybody_with_air_compressor_experience.html

 

[D.B.]

Is this going to be a spider system (all of your flex runs coming back to the furnace plentum) or a main trunk running through the attic feeding each run? How many cfm is the blower on the furnace? How many 8" runs? Keep in mind the supply trunk and or any ducts in the attic must be well insulated or the will sweat.

 

[Woodsman]

This is not a simple matter of just providing a layout for ducts (not ducks as implied in a previous post ). You have to account for the friction (pressure) loss through the duct so that the pressure loss is constant across the whole duct system. Not doing this can result in unequal air flows to the desired point of use.

Each room should be checked for adequate airflow by design and then the duct work designed & selected to ensure that air flow is provided where needed.

IIRC, the flex-duct has a much higher friction loss than the sheet metal duct has, which I has the tendency to dive up the diameter of the flex-duct.

Kirk, that's a nice looking duct!

 

[longbow]

I have a ventilation design handbook.............think gentle curves and big diameter ducts..............Right angles are killers

 

[Indy_Guy_77]

think gentle curves and big diameter ducts..............

whoa...wait... What are we talking about again?

 

[IndyGunworks]

I have gentle curves and big diameter ducts..............Right angles are killers

i stepped into this converssation at the wrong time.

 

[scott delaney]

im in carroll county and do hvac for a living and have for the past 25 yrs....if you need help pm me and i can help you